Western Red Cedar Tongue and Groove Fence
I live in the SF Bay Area and am planning to build a privacy courtyard fence. The material I am using is Western Red Cedar. Posts are 6×6 and boards will be 1×6 T&G. I am concerned with expansion/cupping and plan to leave a gap between post and boards to allow for movement. This gap will be concealed with trim (1×3) on both sides and across top (picture frame).
I want the boards to move freely as they expand and contract over the seasons. I am thinking of NOT fastening the T&G boards within the frame to avoid splitting at the ends of the boards during expansion/contraction. One idea is to use an elasticomeric adhesive on the T&G at top and bottom?
Any thoughts concerns or tips. Should I be concerned with cracking/splitting if I do use screws?
A to the G
Gap the T&G joints instead of
Gap the T&G joints instead of pushing the boards tightly together; use spacers of about 1/8" to achieve constistent gaps. This will prevent accumulation of expansion/contraction of the overall width of the assembled 1 x 6's. Expansion will be confined to its effect on each board without crowding its neighbor.
As for each individual board, attach with 2 nails or screws, and locate each one about 1-1/4" from the edge--this means that the expanse of wood between fasteners will be only about 2-1/2"--not nearly enough to cause splitting between them. You also have the high humidity of the SF area on your side, compared to desert climates in other parts of the West.
You may need to pre-drill for fasteners if you plan on fastening quite close to the ends of the boards, like within about 3". Or, you can buy screws of the self-drilling type. These have a tip confuguatation that actually drills out and removes a small bit of wood to ease entry of the screw.
painting the gap in the tongue and groove
my problem with the gap method is the painting of the boards.
1)You should really paint the tongue and groove one coat so that no bare wood shows if there is contraction (also it 100% seals the board which minimise expansion and contraction). But the tongue/groove connection is already tight. I put 1 coat of oil primer on and I could get the tongue into the groove anymore! If I have to really smack it in hard, would it get stuck if there is a bit more expansion in the tongue?
2)Paint in the gap. Can be a bit messy when paint little gaps. Also that paint in there stay together if there is expansion and contraction?
Hill and Dale Fence
You might consider a hill and dale fence. This was popular all over Calif. when redwood was plentiful. Dado the posts to accept the T & G. Just drop it in the slot, no fasteners needed. 2x horizontal at the top (and bottom if you want). T & G can expand and contract all it wants. The name comes from the horizontal boards being cut to follow the angle of the ground under each section of fence. There must still be a billion board feet of clear RW in these fences. Probably a lot is still salvagable.