Gypsum Roof Deck Thickness

Gypsum wallboard also called drywall is much quicker to install than plaster and the finished effect is a smoother wall.

Gypsum roof deck thickness. Flexural strength can be assumed to be 33ksi unless a new single ply system is contemplated that requires a higher pull out strength. I have generally seen the tees spaced about 30 to 36 on center. Densdeck roof boards are easy to. Densdeck roof boards are fm tested and approved as the only 1 2 gypsum product to meet the calorimeter requirements for conventionally insulated decks.

Factory laminate from two 25 mm 1 inch thick gypsum panels with top panel edge set back along sub purlin edge not more than 13 mm 1 2 inch. Edge encased in water resistant paper. According to fields corp the compressive strength of the gypsum is 500 psi. The gypsum concrete which spans tee to tee encases the tees and.

Local building code will require a minimum thickness or type of gypsum wallboard in some situations. Thickness of a steel roof deck can be determined at a roof hatch where the edge of the deck may be available for measurement with a micrometer. Special galvanized wire mesh draped over the bulb tees distribute vertical loads to the bulb tee system and resist diaphragm loads. When it s not regulated industry standards will help you determine the best panel thickness for your project.

The bulb tees which are very strong vertically but quite flexible horizontally provide the long span strength. The poured gypsum roof deck consists of steel bulb tees a form board usually composed of gypsum or fiberglass wire reinforcing mesh and the gypsum concrete. Each plank weighs approximately 135 lbs. Typcally the poured gypsum deck is about 2 to 3 thick not 1 2 as you previously mentioned and is supported by bulb tees.

The fiberglass mat faced noncombustible as described and tested in accordance with astm e136 nonstructural gypsum core panels provide superior fire resistance and protection from hail damage and hold up well under normal construction and maintenance foot traffic while stiffening and stabilizing roof decks. Tested in accordance with astm e84 its surface burning characteristics are flame spread 0 and smoke developed 0. No securock roof boards will cut with ordinary utility knifes using a score an snap method. 2 1 gypsum plank roof decking figure 1 2 1 1 gypsum planks are normally 2 inches thick 2 feet wide and 8 feet long and are factory laminated of two gypsum panels.

For thicker boards like securock 1 2 gypsum fiber two scores will be necessary. Note gypsum planks also come in other sizes. Formboards placed between the bulb tees contain the fast setting poured gypsum roof deck. For 5 8 securock gypsum fiber a tool such as a circular saw will be necessary.