wood movement in wood panel wall

  • Advertise with us

« back to Designing Woodworking Projects forum

Forum topic by leaf9900 posted 05-01-2016 09:29 PM 681 views 0 times favorited 7 replies Add to Favorites Watch
View leaf9900's profile


2 posts in 901 days

05-01-2016 09:29 PM

Hello, I’ve included pictures of a wood panel wall I’ve been working on. As you can see, I’m going for the flush look. Unfortunately, I didn’t start thinking about wood movement and moisture content until yesterday after finishing almost the whole wall. My question is, is it necessary to leave a space between each row to allow for expansion? I live in Florida. It is May so the humidity will climb in the next month or so. Then it will drop drastically in fall and winter. I leave the nearby window open 24-7, 365 and never use air conditioning or heat. So the room is not climate controlled. I’ve sealed the fronts of the boards. I’m thinking I should at least take the panels off, seal the backs and sides, put them back up and see what happens. I figured before doing this, I’d ask you all. I just started with woodworking and building my shop about 6 months ago so this is actually my first project that I’ve done not for my shop so I really don’t want to screw it up and I would like it to last for a long time.

The wood is southern yellow pine (the brown wood), old fence slats (white painted wood) and the smaller gray pieces are hardwoods from pallets. There’s about 2 longer panels of poplar. All the wood has been dried in a kiln and checked with a moisture meter. Each panel is a little less than 3/8 thick. I’ve had all the wood sitting in my shop for about 6 months so it’s acclimated. I’ve secured them with screws on some and nails on others. Would anyone recommend construction adhesive?

Thanks a lot for the advice!!

7 replies so far

View jdh122's profile


1039 posts in 2962 days

#1 posted 05-02-2016 11:40 AM

There’s a very strong chance that you’re going to have problems with that construction method. Sealing the backs will help slow the expansion and contraction but won’t stop it. Construction adhesive is not a solution either. I think you need to leave a space between the boards – the thickness of a quarter is probably enough. And nails are better than screws as they can move slightly up and down the stud as the board moves a bit, although with a space between you should be OK with screws since the boards aren’t all that wide.

-- Jeremy, in the Acadian forests

View rwe2156's profile


3090 posts in 1625 days

#2 posted 05-02-2016 12:07 PM

Sealing the back will not prevent movement.
Wider the board = more movement.

If it weren’t for the wiring, you could run a sawzall blade down every joint.

Bottom line I wouldn’t do anything with it because most of the boards look pretty narrow.

-- Everything is a prototype thats why its one of a kind!!

View Kazooman's profile


1144 posts in 2097 days

#3 posted 05-02-2016 12:23 PM

Sealing the back will not prevent movement.
Wider the board = more movement.

If it weren t for the wiring, you could run a sawzall blade down every joint.

Bottom line I wouldn t do anything with it because most of the boards look pretty narrow.

- rwe2156

The width of the boards is irrelevant. The amount of expansion over a given section will be the same whether the panel is made up of 1” boards, 2” boards, 6” boards or whatever combination.

That wall is going to be trouble. If it was assembled when the humidity was high then it will probably open up some cracks when it dries out. On the other hand if it was assembled during a period of low humidity it will probably buckle when the moisture goes up.

View splintergroup's profile


2304 posts in 1367 days

#4 posted 05-02-2016 04:52 PM

Kazoo man got it.

If you only finish one side, you greatly increase the chance the wood will cup as the moisture changes. There is nothing you can do about the wood expanding, eventually the moisture will get in there. Aside from the advice of installing when the humidity (and wood moisture content) is highest, the only solution I can think of would be to allow the boards to ‘float’. This can be done by running grooved boards along the length of your studs and stacking your strips into those slots. Alternatively you can install the boards with the required gap and ‘shiplap’ them if you don’t want the gap to show.

View leaf9900's profile


2 posts in 901 days

#5 posted 05-02-2016 06:50 PM

Thanks for the info everyone. I’m going to wait and see what it does while fully expecting that I’ll have to take the wall down and try again.

View DrDirt's profile


4464 posts in 3887 days

#6 posted 05-02-2016 09:16 PM

you may be OK… it is certainly (absolutely) going to move, but it will move just like a hardwood floor does. and those are also only typically finished on one side.

But you are there in Florida… seems it is ALWAYS pretty humid, (well above the 10-12 % in the wood), so not sure how much it really is going to MOVE… versus where it is at w.r.t. width/moisture content right now.

-- “The two most important days in your life are the day you are born and the day you find out why.” Mark Twain

View ArtMann's profile


1081 posts in 961 days

#7 posted 05-03-2016 04:50 PM

This wall represents no more of an expansion problem than a real prefinished on one side hardwood floor and most such installations are no problem. I would take no remedial action until it becomes obvious that it is necessary.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics