Wall finishes

[Carl Beckett]

Hello all,

I know it's specific to local codes, but what are the experiences here for using wood products on the wall, in terms of codes?

I would like to use plywood or other wood based paneling, on top of the insulation.

Wondering if I might be required to use drywall. Thoughts?

(calling my building inspector doesn't work, but I will call a couple local contractors, and dig into the state code a bit myself)

[Todd Burch]

Hi Carl, I don't know the answer to this. My plan for my shop (and house) is to use horizontal T&G planks. (A country setting). My friend did this to his country house, and his builder wanted to install sheetrock first. $10K of sheetrock, taped and floated, then covered with 1X4 x 5/16" T&G pine, then painted. Sheet with never be seen. I asked why the sheetrock first - my friend told me the builder said to keep dust from insulation from coming through the horizontal siding. But the insulation is spray foam. I didn't understand this.

[Thomas Bank]

Speaking as an architect, the first issue would be whether a fire-rated wall is required. For example - between a garage and living space. If so, then you'd be required to have something like 5/8" fire-rated gypsum board each side - what is over top of that can be a variable. In commercial settings, we get into flame spread ratings for materials. Particularly if it is an assembly space. Even with these codes, there have been some unfortunate incidents - often with untreated fabrics that were added in decorating the space after the "architectural" work was done.

Having said that, there is more latitude in residential work (if this is a commercial shop, that is a different issue). Wood panelling or plywood is going to be less likely to ignite and burn than something like carpeting or curtains. Truthfully, the scraps of wood, sawdust, and other materials in your shop are likely to be a greater source of combustion than wood wall or floor surfaces. I'd use some common sense, though. Obviously, I'd stick to fire rated materials around an area where you might be doing something like welding.

Although it has the potential to open a can of worms, it is also something to discuss with your insurance agent. It isn't good to find out after an incident that they are going to deny a claim because of an activity. I've seen claims denied because someone was welding in their garage or had a hacked together "spray booth" that the insurance company didn't know about.

In relation to T&G, there can be an issue of flame spread through the cracks. I know, somewhat unlikely. But that is why they typically require some backing material for it. It is also why even if you used the fire-rated gypsum as an underlayment you have to tape and mud it. The fire rating is only if it is a continuous surface.

[Joe Angrisani]

.....calling my building inspector doesn't work....

How is this possible? They ARE the local code. I'd call or be at their counter at 9am Monday morning.

[Thomas Bank]

How is this possible?

Even as an architect, I deal with this at times. They really are not supposed to design for you because that makes them liable. Some take that more strictly than others. When I've dealt with such a situation, I've typically presented a case to them - e.g: "The code says that I'm required to do such-and-such. But due to these circumstances, it is a bit of a grey area and I propose doing this-other-thing for these reasons, which I feel covers the intent of the code. Do you feel that is a valid interpretation of the code?"

[Carl Beckett]

Thanks all, for the replies.
Thomas is correct, my inspector refuses to answer any 'design' questions of any kind. He wants to inspect, and veto. No other guidance. ( turns out the electrical inspector is pretty reasonable though, so it's specific to the individual)

The shop is a detached structure with no second floor. I was thinking of drywalling the ceiling, but wood paneling on the walls. Fire code is exactly my concern. I cant afford to put it all up and then takeit down and redo. Connecting with the insurance company is another idea..... Although likely to come back to a question of meeting code or not.

Will just have to find someone intimately experienced with local code.

[Joe Angrisani]

.....They really are not supposed to design for you because that makes them liable.......

Wow. I guess it all depends on who you get. My local inspectors were very helpful. VERY helpful. Very welcoming. I asked, and had answered, several specific questions about how THEY interpreted the code and how THEY wanted it done.

[Thomas Bank]

I cant afford to put it all up and then takeit down and redo.

It shouldn't be a matter of doing it and then having to undo it, though. Did you submit plans? Typically they review the plans and call out any problems - not let you build something and then make you take it back down.

And, as I said, they typically won't answer a generic "what should I do" or "what should I use" question but if you say "I am planning to use (for the sake of argument) 3/4 T&G plywood, but do you require 5/8" fire-rated gypsum board" they should answer a question like that.

[Thomas Bank]

I asked, and had answered, several specific questions about how THEY interpreted the code and how THEY wanted it done.

As I mentioned above, it does depend on how the question is asked. Carl wasn't clear on that in his initial post, but if you have a SPECIFIC question you should be guaranteed an answer. There is a difference in asking if "plywood or other wood based paneling" is acceptable and asking if a specific thickness and style of material is acceptable.

[Don Jarvie]

What does the insurance company consider the building? Most likely a garage or out building and it will probably be covered for 25,000 unless you up it. This will cover the building and the contents covered by your homeowners policy. As long as your not using it as a business, then it's a different story.

I did plywood with drywall ceilings (3/8) because its lighter.