Naturally, all drywall are fire resistant or insulated concrete forms (ICF) in Australia. This type of building material was first developed in the year 1916. It is composed of a layer of gypsum plaster that is compressed between two sheets of heavy paper. This gypsum is known as a natural material that has high moisture content. In case of exposure to fire, the moisture will turn to steam which will help suppress flame. There are two types of drywall- the X and C. These are fire resistant and are known as fire rated wall. Fiberglass is added to their gypsum core. The C type gets to have more fiberglass content and a form of vermiculite which is responsible for stabilizing the gypsum core that is under heat.
5 Steps to Assemble
You should double the number of your type X sheets to achieve a simple system that is installed on fire-resistant fiberglass insulation. Every sheet should be at 5/8 inch. A type X drywall is rated to be to resist fire for an hour, so two layers would produce a two hour firewall. Then, you should put these sheets together either on one side or you can use one sheet on every side of a wall. This should only be done in times when the material that is being added would not affect other construction.
For two hour rating, you should use a thicker drywall, in case double sheeting is not possible for you. You should cover your wood framed wall with a single layer of ¾ inch type X drywall that is rated for 120 minutes of fire resistance. Be sure that your drywall has been approved under ASTM standard. Check if there are markings on it or you can ask the supplier if it does meet the standard.
Using steel studs, you can build a two-hour exterior wall, instead of wood, and a special metal stud fiberglass insulation that is between the studs. You can install a 5/8 inch type C drywall on its interior surface and ½ inch of gypsum sheathing in its exterior. Finish up the wall with an inch coat of cement gypsum plaster.
Use two layers of ½ inch of type c drywall and steel studs on every side of the studs for two-hour fire rating on its interior wall. Then, mount a 1 ½ inch of fiberglass barrier on the inside of the studs. You can also make use of a fiberglass-rated for use in a fire rated wall.
You can consider some special wall assemblies from a manufacturer who supplies wall components that combines a type C drywall that has a special insulation for fire-resistance and sound-proofing. There are some assemblies that make use of 3 or 4 layers of type x drywall in case of a double stud configuration so every segment of the wall will have two vertical studs instead of one.
By simply following these easy steps you can save time and money as you can assemble your own two-hour rated fire wall.