Firewall design Help needed

[Colonial Cobra]

I'm converting three adjoining buildings from warehouses to occupied space.
By code they need to have a 2 hour firewall between each space. Which should be 2 layers of 5/8 drywall.
The question is; two of the areas are separated by an 8" block wall, another two by steel sheeting. Do these walls have any effect on the rating???

Thanks
Brad

 

[jimindm]

It may not be as simple as stacking drywall. Instead of two layers on one side, they may want a layer on each side.

The block I would guess if you have no penetrations, you could glue the drywall on each side. I would guess that some one makes a fire resistant adhesive for this kind of application.

The steel would depend on what it is and also penetrations. Could you attach the drywall on it, sort of like a steel stud application.

The walls may have some fire rating to it the way they are. The industry has standards, and if both walls are made of materials common in the construction industry, it will be easy to figure out. The manufacturer likely has a rating on it. Both will likely need some help either way with the application of drywall.

In the end it really does not matter. What you need to do is deal with what ever authority that has made that two hour fire rated provision. Do not try to reinvent the wheel, and just do it the way that they want it. They are the one that will sign off on it anyway to give you an occupancy certificate.

 

[willymakeit]

Google U.S. Gypsum and other drywall manufacturers. Their fire wall systems are based and tested on U.L standards and generally are only what the code official's will recognize.
There will be certain caulking's ect. to use. I personally like Hilti FS One.
These systems will cover the type of wall construction, gage of metal stud [ if that's what you are using] ect. Its not hard but the devil is in the details.

 

[Architorture]

Really need a lot more information in order to draw any conclusions. Since you are in va at least we known you are under the ibc model codes. One of the main factors is going to be your construction type and occupancies involved.

Also are you sure you need a "fire wall" and not simply a "fire barrier"? They have significantly different requirements. Typically when a fire wall is installed the separated portions are considered to be different buildings and the collapse of one portion cannot allow for the collapse of the fire wall. A fire barrier is typically used to separate different occupancies in a single building.

Make sure you clarify that issue first. I'd almost be certain your existing walls would not satisfy the fire wall requirements. They may be able to be fire barriers with some modifications.

Also when looking at existing walls it is easiest to go to the prescriptive fire rated construction portion in the code. Rarely will any existing construction not originally built with a rating satisfy the requirements found in UL designs.

 

[Architorture]

Also is the building sprinklered? That generally makes life a lot easier.

 

[6768rogues]

Do you need a fire wall or a fire barrier? There is a big difference.
There are publications that describe archaic construction materials and assemblies and their fire ratings.
I agree with the post by Architorture. If you don't know the answers to your questions, it is time for you to look for a design professional.