Lightweight Concrete Roof Fire Rating

Fire endurance of structures figure 5 shows the effect of fire on the resistance of a simply supported reinforced concrete.

Lightweight concrete roof fire rating.

Structural function or both. The fire resistance of the two layer together is determined by. Bxuv d949 fire resistance ratings ansi ul 263 7 5 12 8 32 am. The 1 1 2 in.

Because lightweight concrete shrinks when it cures a minimum of 1 1 2 in. 1 normal weight 147 153 3 1 2 1 1 2 normal weight 147 153 4 2 normal weight 147 153 4 1 2. Many buildings require an hourly fire rating as part of build ing code mandated designs. 1 inch 25 4 mm 1 pound per cubic foot 16 02 kg m3.

The light weight is achieved through use of expanded aggregates such as perlite or vermiculite air entrainment or both. 38 mm is required to minimize the cracking that can be expected during the curing process. Dry unit weight of 35 pcf or less and consisting of cellular perlite or vermiculite concrete. Fire resistance of concrete is the ability of concrete to withstand fire or to give protection against fire.

Normal weight or lightweight concrete. Criteria for coreslab to carry a 2 hour fire rating is found in chapter 7 of the international building code 2000 sections 703 3 and 720. Typically the code may require a one to three hour fire rated roof system for protection of life from interior fires. Concrete masonry is widely specified for fire walls and fire barriers because concrete masonry is noncombustible provides durable fire resistance and is economical to construct.

Fire resistance ratings of two wythe concrete walls for si. Chapter 7 of the international building code ibc refs. Lightweight insulating concrete is also considered non combustible and nailable. Assembly rating hr concrete type concrete unit weight pcf concrete thkns in.

Fire resistance of two layer concrete walls floors and roofs. The rn0 59 value for one 1 2 to 3 1 2 airspace is 3 3. Lightweight concrete the second choice for achieving a one hour fire rating in most ul designs is to pour lightweight concrete directly to the wood subfloor. Lwic systems can achieve a real cost savings of 1 00 to 1 50 per square of roof area for 1 1 2 hour or higher.

The westford ma based national roof deck contractors association has published guidelines for rehabilitation of old gypsum decking. The duration of time that an element such as beam column wall floor or roof can endure. Floors roofs and walls built from one layer of semi light weight of light weight concrete and one layer of normal weight concrete and each layer thickness is equal to 25 mm or larger. 2 3 governs materials and assemblies used for structural fire resistance and fire rated separation of.