I’m going to be installing 5/8” tongue and grove on the ceiling in my kitchen on the main floor (a bathroom and bedroom are on the second floor above the kitchen).

There is no ceiling there right now. It’s open to the floor joists.

I’ll be putting 1 x 3 strapping up so that I can level things off (as well, the direction of the the boards will be going parallel to the floor joists, so strapping is needed)

My initial thinking was to put 6 mil plastic up to prevent dust from coming through the cracks. Then, I was worried about moisture getting trapped between the boards and the plastic, possibly creating mould, so then I was thinking of typar which is breathable.

After doing some reading, there were considerations about putting drywall up first, then the T&G. I don’t really see the value in this (but do see the $$ and time!).

I also couldn’t see/find information in the building code.

So, I’m thinking of using the typar. Is this an appropriate approach? Is there are requirement for drywall?

I’m in Ontario Canada (if that is a consideration regarding building codes)

Thanks for any input provided!

  • You absolutely must contact your local building inspection office and get their opinion. Jun 9, 2021 at 21:12
  • Sound deadening and fire blocking are benefits of drywall. A finish coat of mud will seal all dust. Also yiu can supplement your edge stapling of the tg boards with adhesive to the drywall
    – Kris
    Jun 9, 2021 at 22:23

2 Answers 2


I do not think T&G boards alone are best for this kitchen because of fire risk. It might even violate the code. At the very least you should put drywall first and then the t&g boards over that.

But a much better solution would be to forget the t&g boards and instead put on a "tin" ceiling over drywall. This would add the design you want with a very high level of fire protection.

Modern metal panels for ceilings come in a wide variety of finishes and have several different attachment methods. My wife wanted a tin ceiling in an 8' x 8' vault in our kitchen and it was not that hard to DIY. The type she bought was 2'x 2' panels from American Tin Ceiling, but with a design that makes it appear to be 1' x 1' panels.

If your ceiling joists are 2' on center, these 2x2 panels would be perfect fit. You would put the cross strapping on as you planned and then attach more of the same strapping to the exposed bottoms of the ceiling joists to make a square grid of strapping. Put on drywall, tape and bed to firewall grade, then nail the metal panels through the drywall into the strapping. The metal panels are only nailed around the perimeter.

It is possible that the right mastic would allow attaching the panels to the drywall without nailing. The panels are very light.

I followed the mfgr recommendation for our tin ceiling and used stainless steel 18 ga brad nails with a pneumatic nailer. Adjusting the air pressure allowed precise driving of the brads so they are exactly the right depth.


An alternative to strapping is to attach plywood (~ 1/2") on the underside of the ceiling joists, then drywall, then the metal panels. This would allow exact centering of the metal panels in the space. I attached two 4x8' sheets of near 1/2" plywood on top of drywall which was already there. Then I nailed the metal panels to the plywood with 3/4" or 7/8" long 18 ga stainless brads.

Exact centering of the pattern in the metal panels becomes important in positioning ceiling light fixtures. From the living space side you want the fixtures to be symmetrically located in the kitchen ceiling, but I also wanted each of our four fixtures in the center of one of the four squares that make up each panel. I used a keyhole saw on a drill to cut the holes for the four boxes. In retrospect one modern multiple LED fixture in the center of the space might have been better than the four we put in.

  • Thanks for the details and input Jim. My wife is pretty adamant about the T&G. Me, I could go with the tin....but she owns the kitchen and I own the garage! Your kitchen work sound great. I’m thinking you might have done that work prior to Covid. Given the cost of plywood these days I’d have to take out a second mortgage to cover that cost! As per the wife, I’ll be sticking with the T&G. Now I’m just trying to determine if drywall is required per code or not. Jun 9, 2021 at 21:13

The T&G boards are usually installed right on the ceiling joists.

The tongue will move in the groove with humidity, but not enough to make a gap or let dust through. That’s assuming a regular-size tongue (10 mm).

  • Thanks Vebjorn. I think I’ll go the extra step just to ensure dust doesn’t make it through the gaps. (I’m in a century home and the dust from the second floor is shocking!) I’m just not sure if that extra step is going to be just the typar or if the building code requires drywall regardless of whether you are putting up T&G or not. If building code requires drywall, that will be the block for dust. Jun 9, 2021 at 21:26

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