Roof deck is not designed to act compositely with other materials. Roof deck acts alone in transferring horizontal and vertical loads into the building frame. Roof deck rib openings are usually narrower than floor deck rib openings. This provides adequate support of rigid thermal insulation board. Roof deck is typically installed to endlap approximately 2"" over supports. However, it can be butted (or lapped more than 2"") to solve field fit problems. Since designers frequently use the installed deck system as part of the horizontal bracing system (the deck as a diaphragm), any fastening substitution or change should be approved by the designer. Continuous perimeter support of the deck is necessary to limit edge de- flection in the finished roof and may be required for diaphragm shear transfer.
Standard roof deck finishes are galvanized or primer painted. The standard factory applied paint for roof deck is a primer paint and is not intended to weather for extended time periods. Field painting, touch up of abrasions and deterioration of the primer coat or other protective finishes are the responsibility of the buyer. It is recommended, however, that any field paint be applied over a small test area of the primed deck and tested for compatibility and adhesion prior to proceeding with field painting. Special paint, or paint to be applied over galvanizing, is available on special order but must be adequately described to the manufacturer before bidding.