T/G paneling challenges - pulling away from walls, cupping, edge flares

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GrumpyDad

Minister of Fire
Feb 23, 2022
1,230
Champion, PA
Hey all hoping we have some carpenters in the group with a good amount of experience working with wood.
I have tongue and groove wood plank paneling that is 6 7/8" wide, 3/4" thick. I'm only about 1/3 of the way done paneling this expansion we put on 2 years ago, as Ive been working on the interior rooms, insulation, wiring, plumbing, exterior paneling, lighting etc - you name it. (only on the weekend by myself).
The paneling that was put up, was put up in various parts of the seasons, from spring > winter with very warm humid summers in between and fairly dry winter. I noticed some paneling that was lined up from one wall to the next was about 1/4 off months later. Oh well. I left what I thought were decent size gaps between edge piece of wood when installed during the lower humidity months. That summer I walked in this room one day, into a bathroom, and there are short runs between two windows next to each other , maybe 10" pieces. They actually expanded and popped my window casing out, and bulged out about 2". So I had to rip those pieces, nail them back and nail back the window casing. Problem solved, or so I thought.

I then went around and noticed I could rubber mallet just about every piece of paneling about 1/8" back toward the wall. Some pieces even 1/4 inch, especially outside wall pieces. I would drop to my knees and give up if I had to remove everything Ive done. I know this is a very humid area, and I have plans to add a mini split and/or a dehumidifier to the crawlspace below to help with humidity. My plan was then to go back painfully and mallet everything back, then re - face nail all my pieces quickly.

Im using 1 1/2 finish nails for 2x4 walls (interior and old house wall) and 2" for 2x6 walls. Everything was face nailed. Which yes I know it isnt the best looking but again, I dont have the time/patience to try and tongue nail. And honestly I didnt even think of it at the time. Which I dont think it matters unless nailing at an angle makes that much of a difference?

I still have the ceiling to do. I was considering adding some panel nails (with heads) every so often to ensure these pieces dont fall from the ceiling some day. I did some test pieces using longer nails , 2 1/2" and appropriate gaps, and they seem to be holding well.

I also wish I went with an eased edge on all the paneling I purchased. Because now you can feel the rough edges of each board when you put your hand up against the wood.

It still looks great. It's poplar, and as the sun hits it, it turns into this almost like cherry like appearance. I did not plan on doing anything with it at all as far as finish. Poly makes things turn orange. I was going to poly the bathroom paneling and that was it.
 
I had some of my T&G knotty pine “pop” from a wall & I DID tongue-nail all pieces. To draw the pieces back, I located the wall studs, then predrilled & counterbored two holes in each stud location along each board. I used 2-1/2” construction screws to draw the pine back to the studs & covered the heads with wooden plugs. I matched the plug color pretty well, but if you look closely, they’re noticeable.
 
I had some of my T&G knotty pine “pop” from a walk & I DID tongue-nail all pieces To draw the pieces back, I located the wall studs, then predrilled & counterbored two holes in each stud location along each board. I used 2-1/2” construction screws to draw the pine back to the studs & covered the heads with wooden plugs. I matched the plug color pretty well, but if you look closely, they’re noticeable.
I have a paneling nailer that I used for the outside paneling. It shoots coiled , headed nails. I might be able to find heads that are pre finished to closely match.
I thought using longer nails might help but a handyman guy that I know said, that wont matter the wood is pulling from the nail the nail isnt pulling from the studs behind. But it cant hurt to use longer finish nails. The issue is going to be, that finish nails only have small heads.

So when I go to do the ceiling paneling, I am actually using a shiplap product from my local mill. I think it is inevitable that Im going to need to use paneling nails and either just dont care that there are nails showing, or try to countersync them enough with my nailer to then go back and rub some coverup on all of the nail heads if the head colors dont match the wood very well. Id really like to know how others do this. I think even if I had a stable room humidity month over month, I would worry that finish nails wouldnt do the job for many years to come.
Then I ask myself how did the old timers do it when houses had NO humidity control. I walk into places built 100 years ago, and the flooring and paneling look like they were just laid.
 
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Well, you are learning the building, some places can get away with unfinished wood, some can't. I am damp here, living on a river, everything has to have a sealant of some sort or I can watch it fail in short time. Sometimes it helps to put a couple saw kerfs on the back side of a board, some call it a relief, it keeps the board from cupping and allows a hidden area for expansion
 
Well, you are learning the building, some places can get away with unfinished wood, some can't. I am damp here, living on a river, everything has to have a sealant of some sort or I can watch it fail in short time. Sometimes it helps to put a couple saw kerfs on the back side of a board, some call it a relief, it keeps the board from cupping and allows a hidden area for expansion
Well that IS part of the problem. No strain relief on the majority of the wood and it is unfinished. Finishing honestly doesnt do much though, it only delays the inevitable. I tested thoroughly. Sealing just the front, then sealing all six sides, then unsealed. Eventually the wood absorbs the moisture. Im always open to be able to seal down the road. Although after decorations etc are installed sure it will be harder. Or heck, dare I say even paint over solid wood. The ultimate sin.

I too am on, what is classified as a river, with a trout stream running about 20' from the other side of my property and a pond about 10' from my back door. So surrounded by water, in the mountains, in a valley :)

It's rather apparent that many years ago, where Im sitting was under water. The ground is very very rocky and sandy, and the water table is very high.

My neighbors have all had tons of work done, with very finely crafted wood around windows, flooring, paneling etc and it all looks so nice and tight. I really wish I would have gone with a different species of wood, and stained/protected as it would at a minimum delay the impact of moisture so that dehumidification could catch up and remove. My neighbors all run two portable dehumidifiers in their basements (which flood constantly), I have a crawlspace and was considering getting a big industrial joist hanging dehumidifier.
 
I remember from a few years ago, I job I was on, a guy didn't want a dehumidifier for his crawlspace, so the route he took was installing perforated pipe on the ceiling of the space hooked to a what I think was a commercial bathroom exhaust fan that exited to the outside, and on the opposite side he had a small screened inlet, it appeared to do the job, he said it took care of the musty odor and metal objects in the crawlspace didn't rust so much. ?
 
I remember from a few years ago, I job I was on, a guy didn't want a dehumidifier for his crawlspace, so the route he took was installing perforated pipe on the ceiling of the space hooked to a what I think was a commercial bathroom exhaust fan that exited to the outside, and on the opposite side he had a small screened inlet, it appeared to do the job, he said it took care of the musty odor and metal objects in the crawlspace didn't rust so much. ?
Well that was an interesting concept. I had fans running under there, then went with a fan that is made to go into a block cavity. It did do anything for me. The moisture levels are just too damn high.
I have to get under there and seal with a good vapor barrier up to the walls. When we bought the place, and then when we did the expansion, we just didnt have that. So I have to do that. Once that's done, anything I do would be better than letting stagnant wet air sitting in there. The investment in time and materials is worth it to me to put a dehumidifier under the cabin and try to stop the issue Im having with the wood.

I also made the mistake of installing my wood stove within 1" of the clearances next to wood paneling. It's drying those out so bad that they are cupping and have 3/16" to 1/4" gaps on the board all around, and that's only after about 5 , 10-12 hour burns!. Imagine what they will look like in a year or 5.
 
Strange,
I have an entire addition of 750 sf and a good bit of the main house done in 1" x 8" T&G.
I've done ceilings & walls, all with 2-1/2" brads and have no problems with sagging or buckling.
I shot a minimum of 3 brads per stud/joist.
I did air seal & first, then paper backed fiberglass insul.
In the main house I shot it over the existing drywall, not a drywall fan at all.

I did take down some existing T&G off the ceiling in the main house (cathedral), and those were nailed by the prior owner with twist shank nails. They were holding well, and a bish to get out.

The existing an newer T&G were all tongue nailed/shot on an angle.
I'll count myself lucky.

Hope you get it figured out.
 
One Question and maybe already answered
Where did you buy the wood and was it Kiln dried?