GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Does it have to be tongue & groove ceiling on beams?

Schnef | Posted in General Questions on

building a cottage that is going to have to remove 3 very large red oaks.  looking at a structure w gothic arch beams, and would love to use “persist method” w wood planking then a hot roof build   Would love to lumber out my red oaks, but concerned that tongue and groove is required for the ceiling.  is it? zone 5a, thanks, Tom

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.

Replies

  1. Expert Member
    MALCOLM TAYLOR | | #1

    Tom,

    There are two different parts to the answer:

    From a structural point of view T&G help spread loads, so for a comparable span between the beams you would need thicker lumber if it wasn't grooved. But if you are getting it milled, having it a bit thicker won't matter.

    If you don't have a T&G to overlap between boards, gaps will appear seasonally. You need to have a strategy for this purely from an aesthetic point of view. Some sort of backing so you aren't looking up at something unsightly.

  2. GBA Editor
    Martin Holladay | | #2

    Thomas,
    When I was a young man without much money, I built a ceiling like the one you describe. (I'm still living in the house.) The joists are a mixture of spruce and fir logs with the bark removed, flattened on one side with an adze. The subfloor above consists of rough-sawn spruce boards, without tongues or grooves.

    I installed asphalt felt above the subfloor, under the flooring (hardwood flooring recovered from a demolition site). As Malcolm correctly noted, the subfloor dries out in winter, and there are gaps between the boards. No one notices. It's a rustic look, but it works for me.

  3. Schnef | | #3

    Thank you both! Your thoughtful and timely responses are amazing!

  4. tommay | | #4

    Well if you are milling your own boards, I would think a simple bevel on each side would work. Small staple nail or adhesive between joints for some overkill.

    1. Expert Member
      MALCOLM TAYLOR | | #5

      Tom,

      A bevel might hide the gap, but tying the boards together with adhesive or nails is a bad idea. It leaves no mechanism for seasonal movement. If the adhesive is strong enough to keep the boards together, it is the boards that will crack.

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |