How do you demonstrate the fire resistance of a metal stud wall?
The fire resistance of a metal stud wall.
In work, the rule of thumb “double plaster is 60 minutes fire resistant” is often applied. But what if the function on the other side is really critical and the client wants to have demonstrated fire resistance of a metal stud wall? Implementation will then have to be under-construction in two ways: demonstrate what is made, and demonstrate the resistance to fire penetration of that part.
Terms related to fire
It is good to define what terms are used and what is meant by them.
- Fire resistance: the number of minutes that a fire penetrates from one side of a wall to the other.
- Fire propagation: the rate of fire propagation in the same space.
- Fire spread: this refers to expansion of fire through the outside air
- Flame spread: this is the rate of spread across a plane
- Flashover or flashover is the self-ignition of materials due to a very high ambient temperature (>300 degrees)
- A fire compartment is a building structure within which a fire remains for a specified period of time. A fire moves through a building through doors, stairs and corridors; therefore, fire compartments and fire doors are used there.
Fire resistance can be divided on the following criteria:
- the flame seal on seal
- the flame density on flammability
- temperature thermal insulation
- thermal insulation on heat radiation
Metal stud wall and resistance to fire
Dry finishing with metal stud walls and drywall makes an important contribution to fire safety. Gypsum products are non-combustible. In the first phase of fire, the high proportion of water in the composition keeps the temperature quite low. Once all the water is burned out of the plaster (250 degrees), what remains is a dehydrated slab that can withstand up to 1,000 degrees. Then the sheet does become unstable; therefore, glass fibers are often added to the sheet.
The resistance to fire spread is always measured on the entire structure, not on a structural component.
The burn-through time of one Type F drywall board is 23 minutes. The burn-through time of 2 drywall panels is 42 minutes. We can then calculate the fire resistance according to a formula (NEN 6073).
The resistance to fire spread for a metal stud wall by 50 mm. C profiles and double plaster 12, 5 mm. is:
Burnout time in minutes = reduction factor x thickness or sum sheet thicknesses
ts;d = burn-through time heated side + 0.65 burn-through time unheated side
ts;d = 42 minutes + 0.65 * 42 minutes = 69 minutes.
Thus, the metal stud wall in the version to be made has a fire resistance of 69 minutes and complies. It is important that all penetrations, sockets and connections meet this value.
