0428

Required Turns for Tightening Using the Turn-of-Nut Method for Flat Surfaces Under Bolt Head and Nut* Bolt Bolt Length Required Turns 1/2\" through 2\" 1/3 turn over 2\" through 4\" 1⁄2 turn over 4\" through 6\" 2/3 turn 5/8\" through 21⁄2\" 1/3 turn over 21⁄2\" through 5\" 1⁄2 turn over 5\" through 71⁄2\" 2/3 turn 3⁄4\" through 3\" 1/3 turn over 3\" through 6\" 1⁄2 turn over 6\" through 9\" 2/3 turn 7/8\" through 31⁄2\" 1/3 turn over 31⁄2\" through 7\" 1⁄2 turn over 7\" through 101⁄2\" 2/3 turn 1\" through 4\" 1/3 turn over 4\" through 8\" 1⁄2 turn over 8\" through 12\" 2/3 turn 11/8\" through 41⁄2\" 1/3 turn over 41⁄2\" through 9\" 1⁄2 turn over 9\" through 131⁄2\" 2/3 turn 11⁄4\" through 5\" 1/3 turn over 5\" through 10\" 1⁄2 turn over 10\" through 15\" 2/3 turn 13/8\" through 51⁄2\" 1/3 turn over 51⁄2\" through 11\" 1⁄2 turn over 11\" through 161⁄2\" 2/3 turn 11/2\" through 6\" 1/3 turn over 6\" through 12\" 1⁄2 turn over 12\" through 18\" 2/3 turn *Application tolerances: 1/3 turn = ± 30° 1/2 turn = ± 30° 2/3 turn = ± 45° Table 9.7 Turn-of-Nut Method Required Turns Unit 9 — Bolting Up of Structural Steel 9.29 UNIT 9

with bolts and tightened to the snug position, conduct the final tensioning using the turn-of-nut method and tightening the nuts in the same order that they were made snug tight. Typically it is the nut that is turned; however, either nut or bolt may be turned, as Figure 9.12 shows. Calibrated Wrench Tightening If a calibrated wrench (commonly called a pneumatic, electric, or hydraulic torque wrench or impact wrench) is used to install bolts, preinstallation verification test- ing (see Objective 6) must be done each day with a minimum of three sets of each lot, grade, length, and diameter bolt. The wrench used must be adjusted to stall at bolt tensions that are at least 5% greater than the required preload, and it must be verified that the bolt head or nut rotation achieved by the calibrated wrench does not exceed the rotation permitted by the turn-of-nut method. Figure 9.12 Rotation to 1⁄2 Turn from Snug Condition Note: See Objective 7 for a discussion of match marks. 9.30 Structural Steel Erection UNIT 9

Calibrated wrench installation is based on torque control, and proper tension is assumed to be reached based on torque, rather than tension, values. To minimize the variation in friction between the underside of the turned surface and the gripped material, hardened washers must be placed under the turned element for this method. This also prevents galling. DTI Method Tensioning high-strength bolts with DTIs is permitted when the manufacturer can demonstrate that a bolt has been tightened to the minimum tension requirements. When DTIs are used, their protrusions must always bear against a hardened sur- face, and that surface should not turn during installation (if a DTI is used with a regular washer, slight movement of the round washer is acceptable). Approximately 1/8\" should be added to the bolt grip to allow for the thickness of the installed DTI. Tip: Single and double lines on the sides of the “chuck” or socket of the wrench can be placed at the needed intervals so that an Ironworker can easily determine the amount of the turn. Unless a “squirter DTI” is used, a feeler gauge inspection is undertaken to determine if a bolt using a DTI washer has been tensioned appro- priately (see Figure 9.13). Since a DTI may not be perfectly centered on a bolt and DTI protrusions may not uniformly flatten, this inspection must be based upon a series of gap measurements. Bolt installation is considered satisfactory when more than 50% of the time a gap is evident but the feeler gauge cannot enter it. At a minimum, one bolt or 1/10 of the total quantity of bolts within a connection must be checked with a feeler gauge. Table 9.8 provides allowable DTI gap measurements. Table 9.8 DTI Gaps Allowed Figure 9.13 Feeler Gauge Check Load Indicator Gaps to Give Required Minimum Bolt Tension (Black Finish Bolts Only) DTI Location A325 & A490 Under the Bolt Head 0.015\" Under the Nut 0.005\" Unit 9 — Bolting Up of Structural Steel 9.31 UNIT 9

Figure 9.14 Two Basic DTI Assemblies and One Showing the Use of a Beveled Washer DTIs may not be substituted for special washer requirements (such as those related to slotted and oversized holes), but may be used in conjunction with them. Figure 9.14 depicts the use of a DTI with a beveled washer, along with two basic DTI assemblies. TC Bolt Tightening TC bolts are tightened using a TC gun (see Figure 9.15), which ten- sions the bolt without impact until its spline twists off at the proper torque. The TC gun is placed on the bolt with the outer socket on the nut and the inner socket engaging the bolt’s spline. If the lengths of the bolts used are too long, the outer (or nut) socket will not engage the nut and the bolt cannot be properly tightened. Figure 9.16 illustrates the installation of a TC bolt using a TC gun. Figure 9.15 Ironworker Using A TC Gun 9.32 Structural Steel Erection Figure 9.16 TC Bolt Installation UNIT 9

If insufficient clearance makes using a TC gun difficult or impossible, a regular hex head bolt may be installed with a standard wrench as long as the bolt is properly tensioned. In this situation, the turn-of-nut method is used, and the bolt has no sheared spline to indicate that it has been tensioned. To indicate that it has been properly tensioned, match marks should be used. Note: Match marks and other inspection methods will be discussed more thoroughly in Objective 7. Unit 9 — Bolting Up of Structural Steel 9.33 UNIT 9

▶▶OBJECTIVE 6: PREINSTALLATION VERIFICATION TESTING OF BOLTS Preinstallation verifi- cation testing (Figure 9.17) is one of the most commonly overlooked aspects of proper bolt installation, but it should not be. Improper instal- lation and re-work, fas- tener failure catastro- phes, and the high cost of replacing fasteners after they are installed can all be avoided if preinstalla- tion verification testing of bolts is performed on every project. Figure 9.17 Preinstallation Verification Testing Note: Although preinstallation verification testing is strongly rec- ommended for all bolt installations, it is required for slip-critical and pretensioned connections. Preinstallation verification testing serves two purposes: 1. To ensure that Ironworkers understand and can perform the tensioning method used on a particular job site effectively and to standard 2. To ensure that the fasteners used can withstand the intended load Preinstallation verification testing is based on the four methods of tensioning bolts, and must be performed at the job site and on a minimum of three fastener assem- blies of each diameter, grade, length, and lot number. To perform the testing, insert each fastener assembly into a calibrator (i.e., a Skidmore-Wilhelm) and tighten the fastener using whichever method will be used to tightened it during the regular installation process, with these exceptions: 9.34 Structural Steel Erection UNIT 9

• Do not use an impacting tool; using an impacting tool will result in a false reading on the calibrator tension gauge. • A hydraulic torque wrench, and some electric torque wrenches, may be used as they are non-impacting. • If DTI washers are used with fastener assemblies, each fastener assembly tested must be checked with the proper feeler gauge. The calibrator dial will show the fastener assembly’s tension value; the fastener must be tightened until the bolt’s minimum tension requirements are met (see Figure 9.18). These requirements are given in specifications provided by the Research Council on Structural Connections. They are also available in the Structural Bolting Handbook (2006). The amount of minimum tension at which a bolt should be installed, however, is equal to 105% of the proof load of the fastener (proof load is equal to 70% of the ultimate tensile strength of a fastener, or 70% of its breaking strength). Figure 9.19 demonstrates the stretching (or bolt elongation) that happens when a 7⁄8\" A325 bolt is tensioned, as well its proof load. Figure 9.18 Fully Tensioned Bolt Figure 9.19 Load-Elongation Relationships for A325 Bolt If a fastener assembly fails (breaks, or the threads strip), or if any part of a hex-head assembly fails, the entire lot assemblies or parts must be replaced. Do not use them in the structure, and inform your supervisor immediately. Unit 9 — Bolting Up of Structural Steel 9.35 UNIT 9

▶▶OBJECTIVE 7: INSPECTING BOLTS Bolting labor is often the single largest cost component of steel erection, consuming up to 40% of in-field labor hours. It is also frequently considered late in the plan- ning process. As a result, it is sometimes done quickly and/or without adequate planning. Indeed, many well-designed and engineered connections are put near failure because of bolts that are the wrong length or improperly tightened. A poor job of bolting up can be caused by many factors, including the following: • improper supervision • poor attitude • little or no inspection • disregard of bolt lists A poor bolting job may necessitate reworking of bolted joints or even the complete rejection of a bolted structure, which may in turn result in significant construction costs and delays. Proper bolting inspection can help prevent or uncover these and other poor bolting problems and dangers, particularly those caused by poor understanding of which bolting methods are to be used and what they are intended to accomplish. There are four types of inspection: visual examination of nut surfaces, verification of match marks, calibrated wrench inspection, and DTI inspection. Visual Examination of Nut Surfaces This type of inspection determines whether or not a fastener assembly has been impacted. Figure 9.20 shows a close-up of nuts after tightening. If you look closely, you should see marks near the edge of each nut that appear “flat.” These indicate that high tightening torque has been applied. Figure 9.20 Close-Up of Nuts after Impacting 9.36 Structural Steel Erection UNIT 9

Note: Heat-treated nuts furnished with some high-strength struc- tural bolts may not show any distortion because of their greater hard- ness. However, a slight burnishing of the edges should be evident. Verification of Match Marks Visual inspection of match markings is relatively simple: no tools are required. Before a bolt is tensioned with the turn-of-nut method, a paint pen or permanent marking tool should be used to create match marks. These marks should be made at a chosen starting point of the element to be turned (whether bolt or nut) and at the desired turn finish point on the steel. A mark should also be made on the element that does not turn (whether bolt or nut). When the bolt is properly tensioned, the match markings on the turned element should line up with those of the finish point, while the mark made on the element not turned should remain where it was placed. Figure 9.12 in Objective 5 illustrates appropriate mark placement for a 1⁄2 turn. Checking these match marks verifies that the required amount of rotation was achieved and that the head of the bolt (or nut if the head was the turned element) did not rotate during the tensioning process. An easy method for placing marks for a 1/3 turn is to place these markings on the bolt and nut at a chosen starting point, and then to place a mark on the steel three points of the nut away from that starting point (counting the starting point as 1; this would also be at the end of the second flat). For a 2/3 turn, this would mean placing a mark on the chosen starting point on both the bolt and nut, and then placing a mark on the steel five points (counting the starting point as the first) or four flats away from that starting point. Note: Never use soapstone to mark bolts for turn-of-nut inspection. It wipes off easily, and does not last long. When working with gal- vanized steel (which tends to be bright silver in color), use a black paint pen; when working with red primered or unpainted steel, use white, yellow, or another light-colored paint pen. When working with gray primered steel, use white or any other color that will show up well on the steel. If preferred, a scribe can be used instead of a paint pen. Unit 9 — Bolting Up of Structural Steel 9.37 UNIT 9

Calibrated Wrench and DTI Inspection Calibrated wrench inspection is simply ensuring that preinstallation verification testing has been conducted daily for fastener assemblies that will be tensioned with a calibrated wrench. DTI inspection involves using a feeler gauge as described in Objective 5 or checking that the epoxy has appropriately seeped out of squirter DTIs. Internal and External Inspections An Ironworker should conduct bolt installation inspection as often as needed for each type of fastener assembly, but in general a visual inspection should be con- ducted after each installation, preinstallation verification testing should take place at least once each day, and, as observed in Objective 5, at least one bolt or 1/10 of the total quantity of bolts within a connection must be checked with a feeler gauge if non-squirter DTIs are used. In addition to the inspections regularly undertaken by Ironworkers, an on-going official inspection is a part of most erection jobs. All Ironworkers should work closely with outside inspectors to ensure that the methods used to tension the bolts for a particular project or connection, and the conditions under which they were tensioned, are properly understood by the outside inspector(s). To ensure uniformity, calibrated wrenches used by inspectors should be tested and compared to the wrenches used to tension the bolts. When match marking checks are conducted, inspectors should routinely watch the process of creating the match marks to ensure that all of the bolts in a connection are brought to snug before marks are placed, and that the marks are placed correctly before tensioning is completed. In general, inspectors are required to check 10% of each structural connection, or a minimum of two bolts per connection. 9.38 Structural Steel Erection UNIT 9

▶ HANDLING AND INSTALLING METAL DECK UNIT 10 ▶ OBJECTIVES After completion of this unit, you should be able to describe the general process of handling and installing metal deck. This knowledge will be evidenced by correctly completing the assignment sheet, performing the skills in the performance exercise assessment, and by scoring a minimum of 70% on the unit test. Specifically, you should be able to: 1. Identify deck types 2. Describe preparations needed before decking can be installed 3. Describe the process of installing decking Each of these objectives is covered in the pages that follow. Unit 10 — Handling and Installing Metal Deck 10.1 UNIT 10

▶▶OBJECTIVE 1: DECKING Statistically, the installation of metal decking is the most hazardous aspect of steel erection. Approximately 60% of all fall-related injuries in steel erection operations are related to the placement, handling, and attachment of steel decking. To help reduce the chance of injury or accident, all Ironworkers involved in the installation of metal decking should be trained in controlled decking zone procedures. These procedures limit access to the leading edge of the deck where the greatest likeli- hood of injury lies. Each sheet of decking has rigid corners and can be very sharp, so Ironworkers working with decking should also remain alert and of course always wear proper protective equipment. Thin gauge metal decking is used in steel erection to stabilize the building frame and to serve as a working floor. It acts as a form for floor slab or support for built up roofing. Deck lengths may vary to suit job conditions, but are usually less than 40 feet. Standard deck width also varies, but full sheets are usually 12\", 18\", 24\", 30\", or 36\". Deck ends are square cut, and any cutting for width, such as at openings or for angular fit, is done at the job site. Composite Floor Deck Composite floor deck (Figure 10.1) has rolled “ribs” with high and low areas. These ribs lock the concrete and the deck together so that they work as a unit in carrying subsequent floor loads. Composite floor deck can be end lapped, but if the embossment of the rib is excessive, the sheets are usually butted up against one another to decrease the amount of concrete leakage at end laps. Figure 10.1 Composite Floor Deck 10.2 Structural Steel Erection UNIT 10

Roof Deck Roof deck (Figure 10.2) has a smooth finish and is used to support the load of built up roofing materi- als. It is usually designed to be part of a structure’s bracing. Roof deck is usually installed to end- lap approximately 2\" over supports, but can also be butted up against the ends of adjacent sheets of decking. Cellular Deck Cellular deck (Figure 10.3) is composite or roof decking with an additional flat bottom plate that adds visual appeal (see Figure 10.4) and can act as an acoustical tool. The high areas of this deck type act as a chase to accommodate cables and electrical systems. As Figure 10.4 demonstrates, when cellular decking is used to hold electrical systems, it must be lined up and installed so that the ribs create a smooth transition at the abut- ting ends of each sheet. The point at which the end of one decking sheet meets another and neither sheet laps over the other, called the butt joint, is usually taped to prevent concrete from entering. Form Deck Form deck uses extremely thin gauge deck material and very low profiles (i.e., the high areas are not very high, so there is lit- tle difference between the high and low areas of the decking). Form deck is used on short spans. It is commonly used in stair landings or working platforms where light-weight con- crete is poured. Figure 10.4 Smooth Underside of Cellular Deck Figure 10.2 Roof Deck Always be cautious when installing form decking: when walking between support steel, Ironworkers can fall through sheets at the side laps. Figure 10.3 Top Side of Cellular Deck with Openings in High Cells for Cabling Unit 10 — Handling and Installing Metal Deck 10.3 UNIT 10

▶▶OBJECTIVE 2: PREPARATION Before unloading and installation of decking can begin, a site-specific erection plan must be distributed to each worker who is unloading, hoisting, landing, or install- ing deck. This plan should take into account any site-specific safety needs, including special consideration for areas where decking will be shaken out but not secured, for side lap areas (see Objective 3), for cantilevered areas, for single-span sections, for openings and penetrations, for a floor’s spandrel line, and for any damaged areas. Inspection To avoid a structural collapse, frame plumbness and connections should be checked before deck bundles are placed on the frame, and temporary bracing should be in place to keep the frame plumb until the deck is placed and secured. Deck bundles must always be placed on a frame near a main supporting beam at a column or wall. When decking is landed on a joist or joist girder-type bays of iron, the joist must be bolted or welded and bridged. Shipping Deck bundles are normally shipped nested in banded bundles that weigh approximately 4,000 lbs. Bundles vary in size due to gauge, length, width, number of pieces, finish, and profile. This information is contained on a bundle tag (Figure 10.5) specific for that bundle. The bundle tag should indicate where the bun- dle is to be located on the structural steel (i.e., the job area – usually one or two bays – where the bundle belongs). It should also indicate the gauge, length, and quantity of sheets within the bundle. Bundle tags may also indicate a bundle num- ber, set, sequence, or color code. These should have corresponding numbers on the structure’s blueprints. Figure 10.5 Typical Bundle Tag NUMBER OF STEEL DECK FABRICATOR CONTRACT NO. CUSTOMER NAME PROJECT NAME PROJECT ADDRESS DECK TYPE, GAGE, FINISH INCHES MARK 334.00 311.00 307.00 PIECES FT. 20 27 20 25 5 25 45 BUNDLE NO. CONTROL NO. BOM BUNDLE NO. XX LENGTH IN. 10.00 11.00 7.00 NOTES X OF X X X X X - X X X - X X X X X TRUCK XX 10.4 Structural Steel Erection UNIT 10

Whenever possible, a pre- planned delivery and erection sequence should be used to install decking. Unloading Unloading decking generally follows the same procedures as unloading other structural steel members and materials. However, when deck bundles are loaded onto a truck, they are loaded so that the longest bundles are on the bottom and so that the bundles are sepa- rated both vertically and hori- zontally with dunnage. This ensures that hoisting slings can be inserted for unloading. Figure 10.6 shows the typical hoisting sling arrangement used to unload a deck bundle. Note: Wire rope slings must always be used to hoist deck bundles. When unloading, never use the banding to hoist deck bundles, and place the bun- dles as close to the main structural bearing element as possible. In ideal situations, when the structural steel is ready to receive the bundles, the decking bundles are offloaded directly onto the structure. When unloading deck bundles directly onto the steel, make sure that the bundles are placed in the proper bay on sufficient bearing (with the bundle bearing on at least three supports, with each end having not less than 2\" bearing). If there is not enough bearing, the structure’s vibrations may dis- place the bundle and potentially cause a severe accident. When unloading bundles, make sure that they are also in the proper orientation, as is shown in Figure 10.7. Figure 10.7 Deck Bundles Staged for Installation Figure 10.6 Typical Sling Arrangement for Hoisting a Single Bundle Unit 10 — Handling and Installing Metal Deck 10.5 UNIT 10

It is very time-consuming to maneuver a bundle of deck into the correct area after it has been landed in the wrong place. If the bundle is not oriented correctly, the entire bundle must be turned around prior to shakeout (or the entire bundle will have to be unstacked and moved). Deck bundles should be landed so that the leading male edge (see Figure 10.12 in Objective 3 for an example of a male and female edge) of the side lap will lead the shakeout. Only when shaking out inverted deck bays is the bundle oriented with the female edge leading. Stacking bundles in one area on the structure should be avoided at all times: doing so can overload the structural capacity of the floor or roof at that area. If full or half truck loads of deck are to be hoisted at one time, additional dun- nage must be provided so that lifting beams and/or other hoisting devices can be inserted. This practice is primarily used on high-rise structures and reduces the number of picks from the ground to the erection floor. For decking deliveries, small packages of ferrules, weld washers, studs, etc. are sometimes carried inside the tractor, so always be sure to look in the cab when a delivery is made. Shaking Out Deck Bundles For safety reasons, sheets of deck are rarely carried entirely free of a structure’s working floor. Not only can the weight of sheets be too heavy to carry reasonably, walking along a beam or joist line while carrying something at your side can bring a high risk of back injury, and wind gusts can present a serious fall hazard. The method that Ironworkers use to shake out decking, then, involves dragging and pivoting the sheets. One Ironworker advances one end of a sheet of deck and, when it is in its approximate final location, places his or her foot on it. At this point another Ironworker drags the other end of the sheet while the sheet pivots under the control of the first Ironworker. The first sheet removed from a bundle is temporarily placed and tacked behind the bundle to act as a working area for the rest of the bundle. Once this is accomplished, a second sheet is laid out and secured so that it sits in its final position in the bay. The rest of the bundle is shaken out ahead of that second sheet and is then lined up and fastened. This continues until the entire bundle is placed. 10.6 Structural Steel Erection UNIT 10

Storing Bundles Whenever possible, do not break the banding on bundles until they are ready to be installed. If bundles are opened and must be left overnight or for any length of time, make sure that they are properly tied down to the structure. Number nine wire, rope, etc., can be used to secure any loose bundles. If storage off the structure is needed, deck bundles should be stored off the ground, with one end elevated to provide drainage (see Figure 10.8). Bundles should be stacked so that there is no danger of tipping, sliding, rolling, shifting, or material damage, and they should be checked for tightness so that wind cannot loosen sheets or work the bundles apart. Use additional securing (#9 wire or doubled tie wire) as needed. Figure 10.8 Typical Ground Storage Unit 10 — Handling and Installing Metal Deck 10.7 UNIT 10

▶▶OBJECTIVE 3: INSTALLATION Decking installation involves layout, fastening (including side and end lap attach- ment), flashing, and opening reinforcement. Layout Care must be given to the layout of decking as it affects the correct installation of flashing, closures, and shear studs. Layout starting points should therefore be well-chosen to ensure proper deck orientation and edge-of-roof or floor slab loca- tion. Since only the exact amount of decking is sent (in predetermined modules), end points must be marked and layout progression must be monitored so that the material is not used up prematurely. It is also important to achieve proper layout of modules and tightness of butt joints so that the initial welds used to safely secure the decking do not have to be removed later in an effort to reposition the decking. Maintaining rib or flute alignment across the structure helps maintain the struc- ture’s overall appearance and reflects good craftsmanship. To ensure this alignment, the Ironworker placing the deck will make a mark where the deck hits any part of the joist or beam. A snap chalk line should also be used at reasonable intervals to help maintain proper alignment of deck panels. Panel cover widths must be main- tained to achieve long straight runs of deck, and alignment can only be achieved by proper adjustment of each deck sheet as it is placed. Cover width errors accu- mulated across a bay cannot be corrected with the last sheets in the run of decking. Roof deck is often left exposed from underneath. Rib alignment must be parallel to the girders at all girder lines to prevent the unsightly condition of misaligned decking and future difficulties. If, for example, decking is completed and one end is against the wall and the other end is 4\" short of reaching the wall, it is likely that extra, un-bidded work will be needed (such as installing unnecessary flashing, alter- ing the designed flashings or closures, or possibly even ripping sheets the full length of the decked area to act as closures). Such misalignment creates very undesirable and uncraftsman-like conditions, which all Ironworkers should avoid. Floor deck corrugations should, if possible, maintain alignment to achieve continu- ous concrete ribs across abutting sheet ends, minimizing concrete leakage. Flutes that do not align can create closure problems. They may, for example, result in a void in the slab, which will prevent the concrete from being poured as it was designed. 10.8 Structural Steel Erection UNIT 10

Fastening Deck units are fastened to a structure by either one or a combination of the follow- ing: welding (including the use of shear studs), pneumatic or powder-actuated pins, and self-tapping screws. Deck manufactures and local building codes will dictate which methods of attachment are acceptable. Welding When welding is used to fasten decking, sheets are usually attached to a struc- ture by spot welding a puddle through the deck, as shown in Figure 10.9. There are many different procedures a welder will have to follow for deck installation, all of them depending on the gauge of deck used and the number of layers of deck to be attached. Most welding procedures for decking involve the use of 60 or 70 series electrodes with a 3⁄4\" puddle and a 5/8\" nugget of attachment. For proper attachment in all instances, however, the deck must be held tightly against the structure with no more than 1/16\" clearance. Shear Studs Shear studs are used to make decking, reinforcing, and concrete work as a unit in the stability of a structure. When needed, the quantity, size, and location of shear studs are indicated on deck erection drawings. Figure 10.9 Attaching Deck Using a Puddle Weld Shear studs are installed by welding (Figure 10.10), and may serve as deck weld attachments. In other words, if a sheet of decking requires 12 welds, but uses 6 shear studs, only 6 welds are required in addition to the shear studs. Shear studs can be installed through metal deck up through double thick- ness of 16-gauge metal. Figure 10.10 Shear Stud Installation Unit 10 — Handling and Installing Metal Deck 10.9 UNIT 10

Pins Both pneumatic and powder- actuated pin attachment (see Figure 10.11) of decking rely on the same principle. The pin is forced through the deck into the substrate material so that the deck is held tightly to the structure while the pin tip is held by the restrictive force of the steel. Since powder-actuated tools work like loaded guns and are therefore quite dangerous, Ironworkers who use them must have and carry on them specific certifications. If you do not have such certification, you cannot use powder-actuated pin attachment systems. Screws Screws are generally used when a structure’s support steel is less than 3/8\" as greater thicknesses wear out the chisel edge of a screw before a structure is pierced. Self-tapping screws are used extensively on roof decks where the underside of the deck will be exposed to avoid having to paint over what might otherwise be unsightly smoked or welded areas. Deck units under 22-gauge normally will require weld washers. Side Lap Attachment Figure 10.11 Powder-Actuated Pin Attachment of Decking Figure 10.12 Methods of Fastening Side Laps of Deck Units 10.10 Side laps of deck units are fastened by button punch- ing (also called side lap crimping), welding, or screws. Figure 10.12 illustrates these different methods, while Figure 10.13 shows a typical side lap crimp. Figure 10.13 Typical Side Lap Crimp (Button Punch) Structural Steel Erection UNIT 10

Caution! Side laps of deck sheets are a particular safety concern for bays where the decking is laid out but not yet fastened. Ironworkers should avoid walking on these areas between long spans as the weight of a worker can sometimes dislodge the side lap and result in a trip or fall. On single span sections, these regions should be avoided at all times. End Lap Attachment Floor deck end laps are normally butted together. If decking is supposed to be lapped at the ends, ensure that both the overlapping sheet and the underlying sheet receive the weld, pin, or screw. Never fasten only the top sheet (the bottom sheet must also be fastened). Figure 10.14 shows overlapping. Figure 10.14 Example of Overlapping A minimum of 11⁄2\" of end bearing should be provided for decking. If there is less than 11⁄2\" of bearing, additional fastening should be provided and the deck end load capacity should be checked by contacting the EOR or the decking manufacturer. Flashing The primary uses of flashing on metal decking are to provide a pour stop for the concrete at the floor perimeter and to control concrete leakage by sealing the deck. In some cases, the end and side laps are also taped to seal against leakage. Figures 10.15 and 10.16 show typical flashings installed on metal deck. Figure 10.15 Typical Cell Closure Flashing Angles Figure 10.16 Flat Plate Flashing Extensions at Girder Line Unit 10 — Handling and Installing Metal Deck 10.11 UNIT 10

Layout and installation dimensions for all flashing will be defined and specified in a structure’s erection drawings. Follow these drawings closely as some flashing will be installed parallel and other flashing perpendicular to the decking or deck units. Deck Opening Reinforcement Most deck openings are located near supporting members (with the deck itself resting on the structural members). However, the deck around small openings may not be supported from underneath as it is around larger openings. Since this can create a dangerous situation for workers, such unsupported areas will likely need to be supported on the top side. Such needs for additional support usually occur at roof sump pans (see Figure 10.17) and for openings of 2' or less. Deck erection drawings typically provide details and instructions on how to handle these openings. Often an Ironworker will need to create openings (cutting into the deck) after the concrete is poured, but there are times when deck openings are cut first. Whenever holes are cut into the deck, some means of fall protection (such as hole covers or tying off) is necessary. Figure 10.17 Typical Reinforced Roof Sump Pan 10.12 Structural Steel Erection UNIT 10

▶ HANDLING AND INSTALLING SHEETING UNIT 11 ▶ OBJECTIVES After completion of this unit, you should be able to describe how to identify, han- dle, and install sheeting materials. This knowledge will be evidenced by correctly completing the assignment sheet, performing the procedures in the performance exercise assessment, and by scoring a minimum of 70% on the unit test. Specifically, you should be able to: 1. Identify the three basic types of sheeting 2. Describe preparations needed before sheeting can be installed 3. Describe different means of accessing work areas and materials to install sheeting 4. Describe the processes of installing the different types of sheeting 5. Describe the installation procedures for sheeting used in solar air heating applications Each of these objectives is covered in the pages that follow. Note: With the permission of SolarWall®, we are using information and schematics provided by them for the basis of all of the technical information contained in this unit on solar air heating technology. The steps to install solar air heating systems for skills practice at your training center and/or work on the jobsite will be similar to, but may differ from, the procedures outlined in this unit, unless installing a SolarWall® product. Note: Sheeting applications that are installed by Ironworkers on conventional steel framed buildings are covered in this unit. For a more comprehensive look at sheeting methods and application that apply to pre-engineered metal buildings, refer to the Pre-Engineered Metal Building Systems reference manual. Unit 11 — Handling and Installing Sheeting 11.1 UNIT 11

▶▶OBJECTIVE 1: TYPES OF SHEETING Thin gauge metal sheeting is used in build- ing erection primarily as a finished product or “skin” on the exterior walls and roofs of buildings. Sheeting was first used primarily in industrial applications on column and truss type buildings such as in steel mills (see Figure 11.1) and powerhouses. It is now widely used in a variety of appli- cations in the commercial market of office buildings, schools, and hospitals, and where a relatively inexpensive, yet attrac- tive, architectural finish is desired. Figure 11.2 shows sheeting installed on a modern building. Ironworkers typically install three basic types of sheeting: single skin sheeting, com- posite foam panel sheeting, and multi-com- ponent field-assembled system sheeting. Single Skin Sheeting Single skin sheeting (Figure 11.3) is just as its name implies: it is a single skin of sheet- ing installed directly onto the framing of a building. Figure 11.1 Steel Mill with Extensive Sheeting This type of sheeting was first introduced during the steel industry boom. When steel mills were starting to be built, a simple exterior covering that was both economical and strong was required for the buildings at the mill. Single skin sheet- ing fulfilled that need, and the sheeting industry was born. Figure 11.3 Installed Single Skin Sheeting Structural Steel Erection Figure 11.2 Sheeting on a Modern Building 11.2 UNIT 11

Corrugated single skin sheeting similar to that originally produced is still used at today’s mills when repair projects are underway; however single skin sheeting has evolved so that it is now available in a variety of profiles, styles, and colors (see, for example, the non-corrugated single skin fascia panels in Figure 11.4). Single skin sheeting is now used in vir- tually all building styles and its architec- tural applications are unlimited. It can be installed both vertically and hori- zontally, and its fasteners can either be hidden in the lap of a panel or exposed to create a pattern or look. Composite Foam Panel Sheeting Composite foam panel sheeting (Figure 11.5) is a complete wall or roof unit of sheeting ready for installation. Each panel is typically 2\" to 4\" thick and is relatively easy to install, requiring a minimum amount of effort. Figure 11.4 Single Skin Fascia Panels Ready for Installation Figure 11.5 Composite Foam Panel Composite foam panel sheeting consists of a rigid piece of foam insulation com- plete with both exterior and interior skins of sheeting. It usually contains a tongue- and-grove type joint that aids in the ease of installation and External skin Vapor barrier Foam insulation Sub-girts creates a weather-tight seal. Multi-Component Field- Assembled System Sheeting As Figure 11.6 illustrates, a multi-component field-assem- bled system may consist of a variety of components, includ- ing sub-framing, vapor barriers, fiberglass or foam insulation, wallboard, sub-girts, liner pan- els, and exterior skin panels. Figure 11.6 A Multi-Component Field-Assembled Sheeting System Unit 11 — Handling and Installing Sheeting 11.3 UNIT 11

These individual components are assembled together in the field to create a com- plete insulated wall system. Single skin sheeting can be used as part of a multi-component field-assembled system (as both liner panel and exterior skin) to create any look or style that the architect may desire. In general, the installation of multi-component field-assem- bled systems is more complicated and time consuming than the installation of composite foam panel sheeting. It is also more complicated to install than single skin sheeting is alone. 11.4 Structural Steel Erection UNIT 11

▶▶OBJECTIVE 2: PREPARATION Before any material is installed, the Ironworker foreman must review all of the drawings and take the time to properly lay out the job and prepare the sheeting for installation. Laying out a sheeting job often begins with a field survey of the existing building or framing to which the sheeting will be attached. If there are any discrepancies in the existing framing, adjustments may have to be made before any materials are installed. The foreman then needs to determine not only where the sheeting is to be installed, but also where it should be unloaded, shaken out, and stored as appropriate. Ideally, sheeting for the entire structure will be laid out before installation begins; how- ever, this is usually not possible, especially on larger projects. Still, in most cases, Ironworkers must take the time to lay out sheeting well ahead of the installation crew so small adjustments can be planned for. To facilitate the installation of sheeting materials, Ironworkers must know how to properly unload, stage, store, and lay them out on a job site. Unloading Sheeting Materials Sheeting bundles are normally shipped in the same manner as decking bundles, and should therefore be unloaded and hoisted in the same way, but with one important difference: sheeting is normally a finished product. It will not be covered by con- crete or roofing material once it is installed, so extra caution must be taken during the unloading and hoisting process to protect it from any damage that could affect its final appearance. Shaking Out Sheeting Materials Once sheeting bundles are unloaded, any further movement, hoisting, and place- ment of the sheets must be done by hand, so carefully planned placement of the bundles is needed to save hours of unnecessary labor transporting sheeting on the job site. When shaking out sheeting, the following must be taken into account: the elevation at which the sheeting is needed; the overall length of the building; the plumbness, levelness, and squareness of the structure; and the starting and stopping points of the installation. Unit 11 — Handling and Installing Sheeting 11.5 UNIT 11

Roof sheeting is shaken out in a manner almost identical to that of decking. A sequencing system may be used to locate and position the sheeting bundles by areas or bays. A distinction between the shaking out of decking and that of roof sheeting, however, is that the numbering system used to identify floors does not apply. Still, different roof levels may exist and therefore some sort of numbering or lettering system may be implemented to identify the sheeting that is to be used in each area. As with the shaking out of decking, good coordination, as well as the proper loca- tion and orientation, of roof sheeting bundles on the roof steel is crucial to produc- ing a smooth-running, efficient, and ultimately profitable job site. A numbering system unlike that used for decking is used in the shaking out of sidewall sheeting. Its bundles are typically labeled only with the quantity and size (length) of the sheeting contained in the bundle. When unloading and shaking out sidewall sheeting near a building, ensure that the locations of the bundles do not occupy the space needed to properly position a swing stage or other elevated plat- form systems used. Note: Because many sheeting jobs involve the installation of new sheeting onto an existing older building, or are done by specialty contractors who arrive on the job site after the steel erector is fin- ished, the sequencing used for steel erection does not always apply to the sheeting process. In these instances, preplanning by the sheet- ing foreman is critical. Storing Sheeting The same storage rules apply to sheeting as for decking (Figure 11.7 shows sheeting stored on a job site). Extra precautions must be taken to protect sheeting from weather damage as any mois- ture that is allowed to accumulate may cause discoloration and/or damage to the sheeting. In addition to one end being elevated to promote drainage, sheeting bundles must typically be covered in such a manner as to allow for cross-ventilation to keep them free of standing moisture. Any special storage requirements are usually noted by the manufacturer on each sheeting bundle. 11.6 Structural Steel Erection Figure 11.7 Sheeting Stored at Job Site UNIT 11

▶▶OBJECTIVE 3: ACCESSING WORK AREAS AND MATERIALS TO INSTALL SHEETING Before sheeting installation can begin, the most appropriate and efficient means of access to the work area and to sheeting materials must be considered and established. Work Area Access Sheeting systems installed on walls require Ironworkers to work on the exterior of the building at various elevations. Working on the exterior of a building usually does not offer the Ironworkers a suitable work platform or area to perform their work, so they must use a temporary elevated platform to access the work. There are several types of elevated work platforms and scaffolds that might be used. These include a swing stage, a spider (or man cage), and an aerial lift. Swing Stage A swing stage (Figure 11.8) is usually an aluminum plank or platform. Figure 11.8 Swing Stage Separate vertical lifelines Suspension cable Outrigger Swing stage Unit 11 — Handling and Installing Sheeting 11.7 UNIT 11

Swing stages are specifically designed for use in installing sheeting, and come in a variety of sizes, with widths ranging from 12\" to 36\", lengths ranging from 12' to 36', and thicknesses ranging from 4\" to 6\". The walking surface of a swing stage is of a raised, serrated design that provides a non-slip surface. Swing stages can also be fitted with custom handrail systems. Wire rope is used to suspend a swing stage from the top of the exterior wall of a building. A swing stage may be suspended from the building through direct attach- ment (with the wire suspension cables attached directly to the structure), with a cornice hook, with a parapet clamp, or with an outrigger beam that extends out from the roof of the building and is weighted down with counterweights (as in Figure 11.9). Figure 11.9 Swing Stage Outrigger Caution! Suspension cables are to be used solely for the suspen- sion of the scaffolding. Never use them as anchorage points for a fall arrest system. A separate fall arrest line for each worker must be suspended in addition to the scaffold support lines and each of these lines must be inspected prior to the start of each shift or any time the scaffold is left unattended. As with all fall arrest systems, be certain that your system adheres to all pertinent regulations. 11.8 Structural Steel Erection UNIT 11

Swing Stage Powering Systems Several systems – including block and tackle systems, “Hi-Lo” motorized climbers, and “turfers” – are available to move a swing stage from one elevation to another. For all of these systems, an Ironworker must be positioned at both ends of the stage and each must work together when raising or lowering the stage to keep it level. The oldest and least expensive of these systems is a block and tackle system reeved with fiber line. This system requires the Ironworkers on the swing stage to pull down on a lead line to raise the swing stage. Despite its cheap cost, this system is very slow and labor-intensive, and so is seldom used today. Probably the most commonly used system today is a “Hi-Lo” motorized climber, a small modular hoist designed to raise or lower a platform safely by climbing a length of 5/16\" diameter wire rope. Any length of wire rope can be fed into the “Hi- Lo,” making it suitable for any wall height. Because “Hi-Lo” climbers are usually powered by an electric motor similar to a 1⁄2\" electric drill motor, and are easy to operate, they can safely and quickly raise or lower the stage to any desired elevation without significant worker effort. In some rare instances a hand powered “turfer” (or “German come-a-long”) may be used to move a swing stage. A “turfer” works like a “Hi-Lo” climber, but is powered manually by a hand lever, and can therefore be very slow. This method is very inef- fective when frequent and lengthy climbs are required. Spider (or Man Cage) Spiders (shown in Figures 11.10 and 11.11) are operated and sus- pended similar to swing stages except that these systems are designed to hold only one person and are suspended by a single cable. The spider platform consists of a small cage with a three- or four-sided safety rail system. Figure 11.10 Spider Figure 11.11 Worker Using a Spider Unit 11 — Handling and Installing Sheeting 11.9 UNIT 11

Aerial Lift An aerial lift (Figure 11.12) can be used for one or two workers. The two types of aerial lifts com- monly used in the installation of sheeting are the scissor type and the boom type. If the sheeting being installed is particularly long or covers a large area, two or more aerial lifts can be used together to facilitate installation and reduce the risk of damaging the materials or endangering the work- ers. Sheeting is flimsy: if pieces are not properly supported during installation, they can buckle, fold up like a sheet of paper, and cause damage or injury. Establishing Access to Materials Since most sheeting work is performed from a temporary work platform just big enough for an Ironworker (or two) and the necessary tools, sheeting is shaken out in the vicinity of the work area. In other words, even after it has been shaken out, it still needs to get to the work platform. This is accomplished by the sheets being fed to the Ironworker(s) on the platform one sheet at a time as they are being installed. This task of “pulling sheets” is often performed by an apprentice as a good means of being introduced to the process of installing sheeting. Depending on the type of wall system used and the design of the building, a variety of “pulling sheets” methods may be used, including distributing sheets through window openings and hoisting them from the ground. “Pulling Sheets” Through Window Openings If a building has window open- ings, such as the building in Figure 11.13, the sheeting operation almost always precedes the window instal- lation, and these openings serve as great access points to transfer mate- rial from the floor directly to the Ironworkers installing the sheeting on the exterior of the building. Figure 11.13 Building Window Openings Figure 11.12 Aerial Lift 11.10 Structural Steel Erection UNIT 11

Generally, through this window method, materials are simply handed out one sheet at a time through the window opening to the Ironworkers performing the installa- tion. This is a fast and economical method to get the material to the Ironworkers, but for it to work effectively, the materials must be shaken out onto the proper floor of the building and careful planning must therefore occur prior to installation. “Pulling Sheets” By Hoisting If there are no access points along various elevations of the wall, the sheets may need to be staged on the ground and hoisted to the Ironworkers as they are needed. One way to do this is to use a well wheel and fiber line. The well wheel is mounted above the workers, sometimes on a mast attached to the platform itself, and as a sheet is needed, it is attached to the end of the line on the ground. The other end of the line is then pulled to hoist the sheet up to the Ironworkers doing the installation. This installation method is both simple and economical since the wheel and fiber line are relatively inexpensive; however, the pulling is labor-intensive and requires that an Ironworker be in great physical shape. Because it is so labor-intensive, this method of hoisting is usually only used for projects that involve the installation of lightweight single-ply sheets. On jobs that involve heavier sheeting (such as composite foam panels) that must be done at great heights, or where speed is a concern, a motorized hoisting device is often used. For these devices, a small diameter wire rope is run through a gate block or fairlead sheave and is spooled onto a tugger motor powered either by electricity or compressed air. To use such a device, an Ironworker on the ground attaches a sheet to the end of the cable and pulls a lever, which results in the tugger motor hoisting the sheet up. Depending on job site conditions, a crane or other mobile lifting device (such as a lull) may be used to hoist the sheets. Always follow all appropriate safe practices, rules, and regulations when rigging. Unit 11 — Handling and Installing Sheeting 11.11 UNIT 11

▶▶OBJECTIVE 4: INSTALLING SHEETING A properly installed sheeting job results in an attractive, well-constructed finished product (with sheet lengths running perpendicular to the support steel) with proper alignment, fitting of trim and corners, and application of sealant. The initial procedures used to achieve this finished product, however, differ depending on the type of sheeting to be installed. Note: Before sheeting installation is begun, the structure should be checked for proper alignment. Although another contractor may need to align and adjust the building or framing, this is often not possible, so any and all corrective action may need to be done by the sheeting contractor. Some sheeting contractors tend to think that aligning is an unnec- essary step that adds additional time and money to the project. However, in most instances, it saves both time and money by uncov- ering problems before any materials are installed. If adjustments need to be made, they can be planned for ahead of time. Note the proper alignment of the sheeting in Figure 11.14. Figure 11.14 Properly Aligned Sheeting 11.12 Structural Steel Erection UNIT 11

Single Skin Application Installation Single skin sheeting is applied directly to a structure’s support steel, and is usually the easiest and fastest of sheeting systems to install. The first step in installing single skin sheeting is to cut and trim it to the needed size. When intricate cuts are required, hand-held metal cutting shears (or “snips”) can be used; when longer cuts are needed, an electric nibbler may be used. If a long, straight cut is needed (such as when trimming the length of a sheet), a hand-held electric or gasoline cut off saw with a 12\"- or 14\"-diameter blade may be used. When multiple sheets require the same cut, the sheets can be stacked on top of one another and several sheets can be cut at one time. Caution! Unlike snips, nibblers and cut off saws will produce significant waste material. Hundreds or even thousands of small, crescent-shaped pieces of waste material can be produced with even one cut by a nibbler. Always be aware of where a cut is being made and where waste material is being deposited. Depending on the type of material being trimmed, if not immediately removed, nibbler shavings can rust and leave a stain on materials they contact. Cut off saws produce an abrasive type of cutting, much like the grind- ing of steel, which usually results in small, hot, sand-like waste particles sprayed out the back of the saw. These particles can easily damage the finished surface of a sheet or glass if either is in their path. It is a good practice to trim and cut sheeting in a designated area away from other finished materials. It is also good practice to clean up sheeting shavings as soon as cutting operations are completed (or at the end of a shift). Never use a torch to cut exposed sheeting. The erratic cut, heat, and smoke will damage the sheet and require that it be replaced. Once the sheeting is cut to the appro- priate size, there are two basic means of fastening the sheets to the support steel. One way is with concealed or hidden fasteners (Figure 11.15) and the other is with exposed fasteners (Figure 11.16). Unit 11 — Handling and Installing Sheeting 11.13 Figure 11.15 Concealed Fasteners Figure 11.16 Exposed Panel Fasteners UNIT 11

Both hidden and exposed fasteners are typically of the self-drilling type, with a small drill bit molded onto the end of each fastener. Even though this type of fastener drills its own hole, the drill tips on the fasteners are not of the same high quality as a good high-speed drill bit, so the drilling of the hole can sometimes be time-consuming. To help remedy this potential problem, the steel is often pre- drilled with a high quality high-speed drill bit prior to sheeting fastener installation. Since exposed fasteners are exposed to the weather, they have a small, visible neo- prene washer under each fastener head that prevents water from penetrating the sheeting surface through the fastener. Because these fasteners are viewable, the normal practice is to “pre-drill” the sheet prior to installation to ensure that all of the fasteners in a particular row are in a straight line and pleasing to the eye. When pre-drilling, workers normally stack several sheets on top of each other, checking that the ends of each sheet are perfectly aligned. Once stacked, measurements are taken and a straight chalk line is struck across the sheets. Holes are then drilled through the entire stack of sheets at each designated location. This method is a quick and easy way to pre-drill quantities of sheets with great accuracy. Special care must be taken when performing this task, however, because one small mistake can ruin an entire stack of sheets. Hidden fasteners eliminate the need for neoprene washers (since they are not exposed to the weather) and for pre-drilling the sheets in a neat, straight line (since they are not visible). When used, hidden fasteners are usually installed through a lip in the panel, which is covered up by the next sheet. If panel installation pro- gresses from left to right, the panel fastens to the support steel on the right side. The left side of the next panel then snaps in to the right side of the panel that was just installed. This way the fastener holds both the right side of the panel through which it was installed and the left side of the panel which then snaps into it. While exposed fasteners can have widths of sheeting in excess of 36\" (with fasteners installed at various points in the middle of the sheet), the sheets used with hidden fasteners are usually no wider than 12\" because the fasteners are only attached on the ends. Special starting and finishing pieces are also needed when hidden fasten- ers are used. Caution! Do not use red chalk as it will likely stain the sheeting. 11.14 Structural Steel Erection UNIT 11

Foam Panel Installation Foam panel sheeting is also relative easy to install, as is shown in Figure 11.17. The panels can either be attached directly to the structural steel sub-framing or to a framing system constructed of metal studs. The panels attach to the frame with a metal clip that is then screwed into the framing system. Because the metal clip attaches inside the lap joint of the panel, it becomes concealed when the adjoining panel is locked into place. As a result, this type of joint works much like the hidden fasteners used for single skin sheeting, creating a weather-tight seal. Where joints occur at the ends of the panels, a variety of accessories such as gaskets and sealants can be used to terminate the panels. Foam panels can be trimmed in the field as needed with a power saw (with either a circular or compound miter saw), and they can be installed both vertically and horizontally. Multi-Component Field-Assembled System Installation Multi-component field-assembled systems are usually installed in stages or lay- ers. These layers can consist of an outer skin, sub-girts, vapor barriers, insulation, sub-framing, and a liner panel. One layer, or sometimes two or three layers, can be installed at a time. Even when multiple layers are installed together, however, the outer skin is usually installed by itself, and in much the same way as single skin sheeting is installed. Indeed, the other layers are usually installed from the inside out, finishing with the installation of a single skin outer layer. On occasion, the installation may start near the inside, and the layers may be installed working towards the outside. Once the outer skin is installed, the work may be finished off by installing the liner panel from the inside. Figure 11.17 Foam Panel Installation Unit 11 — Handling and Installing Sheeting 11.15 UNIT 11

Installing Trim and Accessories Trim and/or accessory pieces are used at many places on a sheeting project, includ- ing at corners, ends, areas of transition, eaves, and overhangs. Figure 11.18 shows trim being installed at a corner. The installation of trim pieces is greatly dependent on the proper initial installa- tion of sheets: when sheeting is correctly installed, trim pieces fall easily into place. Even with properly installed sheeting, however, attention to detail is critical when installing trim and accessories: the sight lines created by trim pieces are the ones most commonly seen by the customer and the general public, so the Ironworker must make sure that these pieces are installed neatly and correctly, with the pieces all plumb, level, and square. Because trim pieces may sometimes create sight lines on more than one surface or may be viewable from several different perspectives, the trim may need to be installed slightly out of plumb, level, or square to make it look more pleasing to the eye. In these instances, great care must be taken when modifying the alignment of the trim pieces as an alignment adjustment done to make one sight line pleasing to the eye may throw another sight line off. At times it may be necessary to make a compromise between the two sight lines. Figure 11.18 Trim Being Installed Warning! Never use trim adjustment to compensate for a poorly installed sheeting job. Eave trim Fascia trim 11.16 Structural Steel Erection UNIT 11

Applying Sealants All sheeting requires some sort of sealant to keep moisture from getting between the sheets and entering the building. Such seal- ants come in a wide variety of textures, consistencies, and application methods, and range from gun-applied butyl or caulk- ing (as shown in Figure 11.19) to pre-formed strips of mastic. Some sealants are factory- applied while others need to be applied in the field. Most hidden fastener systems, for example, have the sealant factory-applied along the lip, which saves Ironworkers time and makes field assem- bly much faster and easier. In some systems, to guarantee that water does not pen- etrate the system, field-applied caulking is combined with a factory-applied sealant. Care must be taken to ensure that the correct type and appropriate amounts of seal- ant are used and that all locations are sealed as required. Always read and follow the manufacturer’s instructions when applying sealants. Sealants are also often applied to trim and/or accessory pieces to stop water infiltra- tion. As with sealant used for sheets, care must be taken to ensure that the proper amount of sealant is used to properly do its job for trim pieces. However, in apply- ing sealant to trim pieces, the Ironworker must be especially careful not to apply an excessive amount of sealant: doing so may result in the sealant leaking out and oozing onto the finished sheeting as the trim pieces are attached. Figure 11.19 Ironworkers Applying Sealant Unit 11 — Handling and Installing Sheeting 11.17 UNIT 11

▶▶OBJECTIVE 5: SOLAR AIR HEATING SYSTEMS Green construction is a growing market force in today’s construction industry (for more information on green construction see Green Construction Awareness Training for Ironworkers). Since Ironworkers play key roles in the many construc- tion processes, Ironworkers are a key workforce in green construction. One partic- ular sheeting application, solar air heating, is poised to help reduce energy waste in commercial buildings. As a result, Ironworkers should be trained in the installation of this particular sheeting application so that they can not only claim the work but also complete the jobs where this sheeting application is used safely, on time, on budget, and with the highest attention to a quality finished product. Solar air heating is a technology that preheats a building’s ventilation or process air. These solar air heating panels install on the exterior of building walls in a manner similar to single skin sheeting applications discussed in Objective 4, as shown in the photograph of Figure 11.20 and schematically in Figure 11.21. Note that in the photo of Figure 11.20 photo voltaic panels are also installed on the roof. Figure 11.20 Ironworkers Local 404 (Harrisburg, PA) With Solar Air Heating Panels Installed 11.18 Structural Steel Erection UNIT 11

Figure 11.21 Schematic of Solar Air Heating Operation on a Traditional Building These perforated panels absorb solar radiation during the day, and the boundary layer of hot air is drawn uniformly into the ventilation system thanks to thousands of small panel surface perforations (a close-up of these perforations can be seen in Figure 11.22). Solar air heating offers a low-maintenance renewable energy solution with a fast return on investment. Figure 11.22 Close-Up 0f Perforated Sheeting Panel Used in Solar Air Heating Applications Unit 11 — Handling and Installing Sheeting 11.19 UNIT 11

There are two main components that comprise most solar air heating systems – the solar heater and the ventilation system. This objective will focus only on the instal- lation of the solar heater. Once the heater is constructed and begins to capture heat, this solar-produced heat must then be ducted to fans for delivery into the building. The fans can either be roof or wall mounted inside of the building. General Notes • Follow all instructions, as detailed in the engineering drawings. • Before installation, ensure that pull-out tests (to ensure that fasteners will have the required holding strength) were performed on the existing wall. • Do not install things that could potentially block the desired air movement inside the solar air heating cavity. • Make sure any dampers installed do not obstruct air flow inside the solar air heating cavity. Note: During summer months it is important to bring in fresh unheated air to a building. This is done using bypass dampers. Bypass dampers are often located on the front face of the SolarWall® system. Framing installation instructions and drawings must be fol- lowed in order to accommodate these dampers. The Solar Heater Components The solar heater consists of three main components, the framing, the panels, and the flashing. The framing provides structural support and creates the air cavity where hot air collects which then travels to the building’s ventilation system. The perforated panels mount on the front face of the framing and collect the solar radiation through their heat absorbing coating. The flashing is used to fully seal the perimeter of the system so that the fresh air must pass through the perforations on the panels and pick up the solar energy (with the exception of the bottom, which should allow drainage of any water that infiltrates). Framing There are a number of different types of structural building walls that a solar air heating system can be installed on. Each type presents a variation on the framing and fasteners used. Note: Before you start the installation, make sure that you have all the necessary required materials, as noted in the drawings. Count all the parts and lay them out in a manner so that they can be easily accessed. Remember that one missing screw can stop a whole project. 11.20 Structural Steel Erection UNIT 11

Before discussing the installa- tion, it is useful to know how to join sections of straight fram- ing pieces together. Being that the structural members usually arrive in 10-foot lengths, it is almost always necessary to form longer sections. There are four basic types of straight structural shapes that are typically used for the framing material: the L-bar, Z-bar, J-bar, and Hat-bar. Profiles of each are shown in Figure 11.23. C-clamps or vise-grip locking pliers are used to secure the parts during the joining of any shape; this helps to prevent any unwanted misalignment in the finished product. All of the dif- ferent shapes should be over- lapped at least 5 inches to ensure a strong splice. Figure 11.23 Framing Material Profiles When joining Z-bar pieces, the fasteners are placed through the web sections, as this surface generally will not have a surface contact. In a case where it would, rivets should be used. The J-bar will require a slot to be cut into the corner of the longer wing section of one piece to allow the two overlapping sections to lay flat. With one piece slotted correctly, the second piece can be slid through the slot with the longer wing of the second piece lying behind the first. The type and number of fasteners will depend on the part size and location. The Hat-bar is joined together by stacking. As with the other shapes, the overlapped distance will be at least 5\". The fasteners are to be put through the web sections, two on each side. #14 × 1\" screws are generally used. Unit 11 — Handling and Installing Sheeting 11.21 UNIT 11

Existing Masonry Wall Generally, an array of hat-clips and Z-clips fasten to the wall, excluding the perimeters where J-bars are used. Z-bars are fastened over the layer of clips to complete the framing and give the cavity depth. This is shown in Figure 11.24. Existing Single Skin Sheeting Wall Z-bars and hat-bars are fastened to the existing wall, perpendicular to the struc- tural members in it. A second layer of z-bars, perpendicular to the first, com- pletes the framing and gives the cavity its full depth as is shown in Figure 11.25. Figure 11.24 Masonry Wall with Framing Members Properly Attached Figure 11.25 Metal Wall with Framing Members Properly Attached Note: In certain cases, generally high volume applications, a front or back canopy will be required to create a deeper plenum for air travel to the air intakes. Be sure to read all instructions carefully before installing the canopy framing, panels, and flashing. 11.22 Structural Steel Erection UNIT 11

Foam Core Panel Wall Depending on the insulating material in this type of wall, it may be compressible when fastened to. In order to reduce compression, 10\" × 10\" compression plates can be used to fasten to both sides of the existing wall to help distribute the loads and maintain structural integrity. A diagram of the framing with the compression plates on either side of a foam panel is shown in Figure 11.26. Figure 11.26 Diagram of Compression Plates Used to Apply Framing to Foam Core Panel Walls The frame is now ready to have panels and trim attached to it. Before this is done, the area inside the collector plenum must be cleaned. Pick up all tools and debris from inside the frame. Check for rags and larger debris that may have been tucked into or around the riser-clips. When this is complete, use a broom or leaf blower to move the dirt and metal particles down from the top of the cavity to the lower edge. Remove all of the small debris. Metal Framing Notes In summary, remember the following: 1. Framing structure material including clips are to be minimum 18 ga. galvanized. 2. Internal framing connections in structural framing are to be made using #14 × 1\" self-drilling galvanized screws, minimum three per connection. 3. Any structural connections made through a surface which will come in contact with the sheeting or flashing are to be made with 3/16\" diameter × 1⁄4\" hold stainless steel rivets, flat end out. Unit 11 — Handling and Installing Sheeting 11.23 UNIT 11

4. Overlap framing sections by 5\" and secure 4. together using provided screws or rivets, as situation requires. 5. Use the specified fasteners (length to be determined on site) to connect the framing to the existing wall. 6. The perimeter metal framing must be sealed to the existing wall using the specified silicone caulking (usually this is Dow Corning 79, or equivalent) and backer rod, as needed. The Ironworker in Figure 11.27 is caulking the metal framing before the framing is installed. Figure 11.27 Ironworker Caulking Metal Framing It is recommended that the trim pieces for the bottom plenum surface of the col- lector be put into place at this time, before proceeding to install the panels. This should be done because the flashing may be set in such a way that part of it will either lay under the sheeting or have screws, which are used to hold the panels pass- ing through it. Form the trim pieces from the flat flashing material provided. The project drawings will show the type to be used and the basic expected dimensions. After removing the plastic protection sheet from the trim, start from one end and secure the trim into place using one of the proper screws every 18\" along the top and bottom of the surface structure. To properly install the screws on an 18\" center- to-center pattern, follow these steps: 1. 2. Make sure that you leave 21⁄2\" overhanging at the start of the wall and the same at the end of the wall (the overhang at the end will be bent back to form trim tabs against the sides of the plenum). Start installing screws with one screw at the top and one at the bottom of the starting point. 11.24 Structural Steel Erection UNIT 11

3. Then, alternate the screw placement. This will set up a pattern that places one screw along the piece every 9\" (one on the top and one on the bottom). 4. Overlap the flashing sections by two inches and secure them together using the painted head screws. Perforated Panels After installing the trim pieces for the bottom plenum, the panels can then be installed. The standard panel material is painted G90-galvanized sheet steel. It can be laid directly over the galvanized support framing and secured using the recom- mended screws as with sheeting in most other applications. Like any other sheeting application, the placement of the solar air heating panels should be measured and marked out to make sure that the proper distances are met. This will help avoid the common problem encountered when putting up a vertical wall; corrugated metal sheets have a tendency to change shape from the top to the bottom when they are being fastened. By starting at the end of the wall where the first panel will be placed and laying out marks at the top and bottom before begin- ning to install the sheets, if the framing was build square and the measured marks are followed then the final sheeting job will be correct, uniform, and square. Note: As with joining any light gauge material, it will be necessary to use the clutch driven screw gun on a light setting to prevent stripping. Note: You will find that the collector panels can become very hot during installation and that gloves are required. Remove the plastic protective sheet from each panel, as shown in Figure 11.28. If this plastic is mistakenly left in place, no air will flow through the pan- els. Put the sheets in a placement order so you don’t have to carry them over each other for final positioning. Figure 11.28 Ironworker Removing Plastic Covering from a Panel Unit 11 — Handling and Installing Sheeting 11.25 UNIT 11

Warning! Each panel can create a large “sail” area (an area that catches a lot of wind, as a sail on a ship). A strong gust can take the sheet away from you, or even take you with it. Try to keep the lead- ing edge facing into the wind and have at least two people moving each panel. When installing sheeting onto the frame, the bottom or lower row is always placed first. This allows the upper rows to overlap the lower and makes it easier for water to run off the sheets. The first row will also set up the placement of the remaining rows as to their exact position. It is very important to have the panels squared to the frame and set to the measured end marks that were pre- viously placed as a guide. If the first panel is even a little off, then the remain-ing panels will follow and become increasingly crooked. By keeping to the marks, and checking often with a level as the Ironworker in Figure 11.29 is doing, the pattern will remain straight and constant from one end to the other. Figure 11.29 Ironworker Checking a Sheet for Plumb The sheets will be secured into place using the specified screws in the pattern that is specified on the drawings or the installation instructions. After the first panel of the row is secured, the remainder of the panels in that row can be put on in the same manner. When placing the next panel, make sure that the overlap is nested correctly and that the ends of the panels line up. When the first screws are put into the framing, hold the seam together so it will not slip. Note: In certain cases, generally high volume applications, a front or back canopy will be required to create a deeper plenum for air travel to the air intakes. Be sure to read all instructions carefully before installing the canopy framing, panels, and flashing. 11.26 Structural Steel Erection UNIT 11

When screwing the sheets together (at the laps), be especially mindful and do not let the screws spin out when they reach the bottom; if they do, the hole will be stripped and the screws will not hold. You should also be certain to hold the panels together because if the pieces separate, the drilled holes will not line up and the panels will not nest correctly. Add panels until the end of the wall is reached. If the end panel needs to be cropped to fit, do so before attaching the panel. The screws at the sides are not to be put in at this time. The second row of panels is now to be put on. The lower part of the panel should overlap the first row by the amount designated on the drawings (usually about 4\"). Secure the sheets in each row in the same manner as the first row of panels. Follow the measured marks on the frame. If followed correctly, the two rows of panels will have a straight appearance. Cutting Panels For the most part, solar air heat- ing sheeting arrives precut to the proper lengths, in accordance to the project plans. Being that this is not always practical and that sometimes site restrictions cause changes, it may be necessary to cut the panels in the field, as shown in Figure 11.30 and Figure 11.31. The cutting of panels was described earlier in this unit. Solar air heating panels have the fol- lowing specific items that make them different from most other sheets when cutting: Figure 11.30 Ironworkers Cutting a Solar Air Heating Panel • The protective plastic sheet has to be removed from the area of the cut. The saw can’t cut through the plastic film without the chance of the plastic catching and binding the blade. • After the solar panels are cut, the fresh edge must be cleaned up. Cutting will create a sharp edge with loose burs that could come off and fall into the plenum. Figure 11.31 Ironworker Using a Shear to Cut a Panel Unit 11 — Handling and Installing Sheeting 11.27 UNIT 11

• With steel panels, be careful not to remove the galvanized coating when filing the edge. If too much is removed, then a galvanizing paint will have to be used to dress up the edge to keep it from rusting. If the cut is in a place where the edge will show, color-matched paint is to be used to coat the exposed area. Sheeting Notes In summary, remember the following: 1. Remove the clear plastic protection sheet from the panels. 2. Install perforated panels with dark side out (exposed to sun). 3. Keep all edges squared and straight when placing the sheets. 4. Self drilling screws are to be placed in the center of each low panel flat, along each framing member, or as otherwise specified on the drawings. Closing the Perimeter and Flashing For a solar air heating collector to work, air must be directed primarily through the panel surface. The ends and sides of the collector must be closed off to stop air from entering. The methods used will depend on the type of collector framing and the condition of the existing wall. The first step is to place the spacers at the ends of the collector panel edges (usually Z-bar). These pieces will help seal the ends of the solar panels to the framing and give support to the future side flashing. Where the spacers are placed will depend on whether the panels start or end on a high or low flat. If the panel edge is on a high flat, then the spacer will be placed between the solar panel and the framing. If the panel ends on a low flat, then the spacer will be placed on top of the panel. Caution! Before cutting, make sure that the intended measure- ments are correct. It could be possible that you are looking to cut a longer sheet when the proper length panel is already on site. Note: Do not apply caulking at the bottom of the panels as this will stop water from draining. Note: The type of flashing and shape are detailed in the project drawings. 11.28 Structural Steel Erection UNIT 11