I currently have 1/2 drywall on my wall sepating the garage, which is now an accesory apartment. The house was built in 1975.
Code says it must be 5/8. It is not possible to take everthing down to add more drywall. Is there another way to increase the fire rating, by either a product I paint on or spray on?
I am getting ready for an inspection, just looking at other options I can run by the inspector if he doesn't like what I have.
They tell me they are trying to work with me to get this apartment passed and legal. Both sides of the wall in question have 1/2 inch drywall.
Best Answer
Intumescent coatings have evolved (I formulate them). It is just a paint now. 3 coats would add 20 minutes or so to the fire rating of the drywall.
Here, narrow clearance homes are required to use intumescent coated OSB on the outside walls.
These paints can withstand up to a year of exposure before being covered up so bad weather is no longer an issue as it used to be just a few years ago.
The old stuff was PVA resin and water soluble (almost edible) ingredients. Now we have encapsulated stuff with tough, exterior grade thermoplastics as the binder. Things have changed :)