5.6 STEEL BUILDING FASTENER INSTALLATION
Correct fastener installation is one of the most critical steps when installing steel building roof panels. Drive the fastener in until it is tight and the washer is firmly seated. Do not overdrive fasteners: A slight extrusion of neoprene around the washer is a good visual tightness check.
Always use the proper tool to install fasteners. A fastener driver (screw gun) with an RPM of 1700-2000 should be used for self-drilling screws. A 500-600 RPM fastener driver should be used for self-tapping screws. Discard worn sockets, these can cause the fastener to wobble during installation.
| CORRECT DEGREE | TOO TIGHT! |
TOO LOOSE! |
OF TIGHTNESS SEALANT SQUEEZED TO THIN, SEALANT IS NOT COMPRESSED ( NOTE SLIGHT CIRCLE OF EXTRUDES FAR BEYOND TO FORM SEAL SEALANT) FASTENER HEAD
MASTIC SEALANT
Proper mastic application is critical to the weather tightness of a steel building. Mastic should not be stretched when installed. Apply only to clean, dry surfaces. Keep only enough mastic on the roof that can be installed in a day. During warm weather, store mastic in a cool dry place. During cold weather (below 60) mastic must be kept warm (60—90) until application. After mastic has been applied, keep protective paper in place until panel is ready to be installed.
SCREW ALIGNMENT
Good alignment of the screws, especially on the wall panels, will give a professional appearance to the wall panel installation. One way this can be accomplished is by pre-drilling holes in the panels at identical locations. Up to 15 panels can be stacked together and drilled using a template panel. Use 1/8” or 3/32” diameter drill bit for panel to structural fasteners and a 1/4” diameter bit for the sidelap clearance holes. It is important to clean metal filings off panel surfaces after drilling to avoid rust stains.
The template panel should be laid out for the proper screw locations in accordance with the building erection drawings. Since pre-drilling will “hand” the panels, it will also be necessary to select the end of the building from which the paneling is to begin. Before drilling the template panel. it should be checked for oroper hole locations against the building framework. Be sure there is no excessive
deflection in the purlins and girts. 
