Tongue and Groove

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Forum topic by Okie72 posted 05-16-2018 06:10 PM 798 views 0 times favorited 9 replies Add to Favorites Watch
View Okie72's profile


7 posts in 1051 days

05-16-2018 06:10 PM

Topic tags/keywords: tg woodworking

Hey all. I am planning on building the attched sliding barn door. Can someone tell me how I need to attach the tongue and groove together to account for wood movement? I attached two of the door i am building and one of a suggested nailing pattern. Any advice would be appreciated.

9 replies so far

View hkmiller's profile


235 posts in 888 days

#1 posted 05-16-2018 06:33 PM

well you could do a dado and the railing the styles of the door and then hook the tongue-and-groove together and let it float in there it would be the same as building a raised panel door

-- always something

View OpensideFlanker's profile


14 posts in 1114 days

#2 posted 05-16-2018 08:25 PM

Just built a gigantic version of same. The bigger the door, the more any discrepancy in the angles of the mortises shows up. If building by hand, I would first suggest using mortising guides to keep everything square when chopping.
For the wood movement, try to figure out how much movement you will expect from your current environment through the worst of the final application environment. It is easy to underestimate the wood movement and have even the best planning go wonky on you. I would T&G all of the panel pieces and, since you would like to minimise the apparent of the movement, bead the wood on the tongue side (masks the opening of the joint during shrinkage period). Also, you will want to finish the panels BEFORE assembly or else unfinished portions will show when the wood is dry. I would rather have a wee bit of rattle than a split door. I would not fix the panels to the diagonal braces.

View Okie72's profile


7 posts in 1051 days

#3 posted 05-16-2018 08:29 PM

OpensideFlanker…when you say bead the wood on the tongue side…do you mean glue on the tongue side?

View Loren's profile


10477 posts in 4454 days

#4 posted 05-16-2018 08:33 PM

This looks like a situation where the tongue and
groove boards are nailed to a frame.

You can make a pair of spacers the thickess of
half the tongue. With a 1/2” wide tongue the
spacers would be 1/4” wide. Put them in between
the t&g boards as you go nailing them. Making
a story stick to lay the t&g boards out evenly
may be useful. You can work from one side
nailing them or from the center out, depending
on the overall width. Figure it out beforehand
so you don’t have really thin boards at the edges
after you cut them off flush with the frame.

View Okie72's profile


7 posts in 1051 days

#5 posted 05-16-2018 09:27 PM

Loren, if I nailed them, how would i accomodate for wood movement? So confused.

View Loren's profile


10477 posts in 4454 days

#6 posted 05-16-2018 09:34 PM

T&g is designed to allow for wood movement.
You just have to insert the tongues halfway
as a rule of thumb. This allows the boards
to shrink or expand without creating gaps. If
the boards are fresh-sawn and damp put them
together closer because they’ll dry and shrink -
which may have been the original purpose of
the joint.

View OpensideFlanker's profile


14 posts in 1114 days

#7 posted 05-16-2018 10:45 PM

Tongue, Groove, and Bead simply uses a bead to visually distract from the T&G joint when it becomes wide during dry periods. It is an old technique. I have attached an image of a beaded T&G joint (beaded on one side). I usually use a #45 Stanley or a wooden side bead plane to make these (I am sure you can also find a tool with a plug to do the same. It really does make the door look better when the joints open. It has nothing to do with gluing (and I would be reticent to use much glue in order to preserve movement).

View clin's profile


1114 posts in 1802 days

#8 posted 05-16-2018 11:17 PM

I made a T&G gate a few years back and struggled with how to do this. It’s easy to float the boards, but you need any gap during dry weather it spread out between boards. Unless you had unusually deep T&G, there’s the potential for all the gap to be on one board and show through.

In the end, I opted to nail each board. However, I put a single nail in the middle of each end. of each board.

A single nail doesn’t cause any stress when the board expands and contracts since it just expands or contracts around the center. This of course assume the board is otherwise free to move. Which of course is the whole point of T&G.

I spaced the boards using roughly 1/8” material. I cut a bunch of 1’x3”x1/8” spacers and fit those between all the boards and lined everything up. Then shot in the nails.

My frame had a groove all around to fit the board. But this groove was maybe 5/8” deep. Therefore I shot the nails (brads really), at an angle. The head of the nail is actually on the board and angle toward the frame. This kept the brad in from the end to avoid splits. And it catches the board well and is deep into the frame.

I only shot the brads in frame the “bad” side of the gate, not both sides.

This has worked well for my gates. There’s really no force on the nails, They just keep each board centered.

These barely showed on my gate, so I left as is, Though used stainless steel brads to avoid the discoloration rust causes. But the brad heads are small and would be easily filled, and are so close to the frame that they aren’t very noticeable.

Something else I think could also work fine would be to glue each board in place. But only put a dab of glue in the center of the board. That way, again, no stress.

Concerning the diagonal. I have something similar on my gates and put a brass screw through wherever the center of the diagonal crossed the center of a panel board. Again, with the attachment points being in the center, and the fact that wood moves little over its length, this creates no stress.

Keep in mind that when the door dries, more of the tongue is exposed. So be sure to put finish on the boards before assembly. And be sure to account for the finish thickness and make the groove wide enough to avoid binding.

While, my application was just a gate, I chose to chamfer the edges of the board. This is another way to sort of dress up the edge and softens the joint. It doesn’t hid it, just makes the whole thing look better.

-- Clin

View Okie72's profile


7 posts in 1051 days

#9 posted 05-17-2018 06:04 PM

Hmm…I have had a ton of feedback on this post. Thank you.

I am considering NOT using t&g and just using plywood and route vertical lines 5.5 inches wide to make the plywood look like planks. this project will be painted….

In my mind, this ensure lack of wood movement…


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