I did not want to hijack Calvin’s topic so started one of my own. — A friend and I are gettaing ready to install a 1×6 Douglas Fir T&G ceiling on his patio. We are going to put the flat side exposed, not the v groove edge exposed. Boards will be nailed & glued to each rafter. The patio is open to the rest of the house attic above and well vented.
The exposed side will be finished with a clear finish, I am not sure of the product yet. Should we apply to all sides and edges?
When installing, should I tap the T&G together for a very tight fit, similar to a floor, or should I just do a “hand tight” fit so there is allowance for expansion & contraction
We are in Austin, TX, so we do get drastic humidity fluctuations.
Also, should I slightly bevel the end cuts so we are not butting flat ends together? I’m thinking this will give a closer, cleaner butt joint.
Any and all answers and other suggestions appreciated.
Replies
Keep in mind that with the top exposed to attic conditions the temperature and humidity differentials will be substantial. Sealing both sides will help to reduce the effect this has on the ceiling.
Definitely seal all sides, including the tongue and groove
Whether to install tight depends on RH at the time of install, and the MC of the material. If you install during the driest part of the year, and the material is quite dry (say 8% MC) then you should probably gap the material slightly and assume that higher RH in the future will cause some expansion. If you install during the time of highest RH, and the material is not particularly dry (say 14% MC) then I would install it tight. I would leave expansion room around the edges as well. You need a moisture meter for wood to plan the install, and some info about RH levels thru the year.