Hard wood flooring buckleing?

tacks Y · February 10, 2020, 09:41:11 AM

I have T&G red oak paneling in my basement. I run a dehumidifier in the spring-fall. But it still buckles some. I plan to use mixed wood on my floor, QS red and white oak, sycamore, birch, maple, hickory, elm, willow, locust and black gum. Most wood not QS. Will I have the same problem? My sub floor is hemlock, white pine with 7/16 osb over it. Hope to remove carpet and install. Wall t&g is not over nailed,4 or 5 nails over 8' up to 8" wide boards. What keeps these boards flat on the floor, more nails? Thanks

DR Buck · February 10, 2020, 10:00:02 AM

I would never install wood on a basement floor. But that's me and my preference. If you have to use a dehumidifier to minimize paneling from expanding and buckling you are definatley getting moisture in, possibly through the walls or the seam along the floor/wall joint. I would be more concerned with mold growth behind it.

At my last place, which had a ground level slab floor, before putting down hardwood (bamboo) to minimize moisture from rising up through the floor I sealed the concrete. First with a thinned roofing tar spread with a squeegee covered with a layer of black felt paper. I then covered that with a layer of 6 mil black poly (plastic). This was then topped with a final layer of 3/4" plywood fastened with Tapcon screws into the concrete. Then I installed the hardwood.

tacks Y · February 10, 2020, 12:16:50 PM

I did not explain this well. The t&g is on the wall in the basement. The flooring is going on the floor above, 1st floor not basement.

Southside · February 10, 2020, 12:20:29 PM

Was the wall material kiln dried? Is there a back relief cut into the wall paneling? The 8" material is not helping you.

Don P · February 10, 2020, 02:33:24 PM

Hard to say without knowing the humidity below and above. Narrower strip will move less per board than wide plank, prefinished is sealed on both sides but ultimately knowing and having control of the rh is the best thing.

Bruno of NH · February 10, 2020, 03:49:18 PM

I have installed my thousand linft of t & g over the years
I have found 8" wide and up needs a face nail or two in the face to keep it flat.
Same goes for wide flooring counter sunk screws with plugs or cut nails and glue on wide pine floors.

tacks Y · February 11, 2020, 03:20:26 PM

When I say buckle I think what is happening is the wood expands and pushes out a board. Then dries some in the winter and pulls back leaving a gap. I did not relieve the back like I should have but the wood was varnished both sides then installed. I am not having a problem with boards cupping. This was kiln dried wood. My t&g cutters seemed to tight and maybe I should not have put it so tight together. Wood is 2" to 8" wide random width. Or left room at the corners to expand. I did not over nail either, just enough to hold on the wall. So what will keep my floor from doing the same?

Southside · February 11, 2020, 03:32:29 PM

The purpose of the back relief is to allow the individual board a place to move within itself before it pushes onto the next one. Make sure you get your wood down to 7pct MC, mill in back reliefs and consider keeping it under 8" wide.

Wudman · February 12, 2020, 12:01:31 PM

Your issue in the basement is moisture (humidity). The wood is picking up enough moisture that it is expanding and doesn't have enough room to move and thus buckles. That is the reason that most commercial production run flooring is narrow (that and cost of raw material).

For your upstairs, that issue should be minimized. Your heat source (translated humidity levels) will dictate the movement in your floors. If it is fairly constant throughout the season, you won't have any issues. If you have wide swings in humidity, the floor will expand and contract with the moisture content.

I have a fairly new home that is very airtight. As we have a number of dogs in the house, I wanted a flooring material that was very durable. I went with Pergo laminate in "Rustic Hickory". This stuff is hard as nails and is supposed to be quite stable. With that said, during the winter, my floor will open several gaps between boards in the length direction. From my mudroom to the master bedroom there is a 61' linear run of this Pergo. Several 3/8 inch gaps will open during the winter at joints. It will move back together in the spring when the heat is shut off and the humidity increases.

I have electric heat pumps with gas logs supplementing the great room. My basement is heated with a forced air wood furnace. At this moment, it is 70 degrees in my basement with 44% relative humidity. Relative humidity dictates the comfort level for humans and wood.

Wudman

DPatton · February 12, 2020, 07:20:39 PM

Did you leave enough space for seasonal expansion and contraction around the perimeter of your T&G wood? There has to be enough space at the edges for this expansion or it will bow the wood up and out. Large wood floor areas like a gymnasium floor require as much as 2" of relief space at the perimeter of the installation for such seasonal expansion. I would say that a typical house sized room installation should probably have at least a 1/2" gap or more for expansion at the perimeter of a wood floor.

tacks Y · February 13, 2020, 04:56:59 PM

No I did not allow for expansion. Is this typical for hard wood flooring 1/2" gap around outside?

Don P · February 13, 2020, 05:17:17 PM

Typically 1/4", base shoe runs 1/2x3/4 although there is usually a 3/4 baseboard as well but not always. My Dad ran tight and to my knowledge none of those houses has ever had a buckling problem. The only time I've had cupping, not even buckling, is when liquid water hits the floor from a leak or huge spill and gets under it. When I was a teenager another contractor friend tried an experiment. He put down the oak floor on top of the subfloor and was then going to frame fast and get it dried in. He was hoping to save the time of working around the interior walls. Well, he got the walls up and we had a big rain, the swelling oak took the exterior eave walls right off the floor.

tacks Y · February 14, 2020, 08:31:28 AM

So another question?? Do any of you install flooring butting the ends? (Not t&g on the end)

Don P · February 14, 2020, 01:54:46 PM

I have, most factory flooring is end matched but stuff from small shops is often not. End matching actually comes from a code provision that allowed using T&G flooring single ply, without a subfloor, if it was end matched, adjacent joints did not occur in the same bay and pieces spanned at least 2 joists. Everyone has forgotten that reason and so the common misconception is that you have to have it. That said if it is other than relatively narrow strip I would end match.

It would be a good idea to get a cheap digital thermometer/hygrometer and start getting a feel for the rh upstairs and in the basement.

trimguy · March 06, 2020, 09:43:25 PM

I just came across this thread, I know its about a month old ,but thought i would comment. I put down a lot of tongue and groove flooring. We try not to go with anything wider than 5". Also put a vapor barrier under it. Especially with the humidity in the basement.

tacks Y · March 07, 2020, 08:33:50 AM

Trimguy, Nice looking job on the floor. What woods did you put in there? Are you routing the ends also? On site? I bought a Logsol 260 to make my flooring and was planning to just butt the ends. Still in the thinking stage and sawing/drying. So far I have Qs red oak, black gum, beech, black birch, yellow birch, sycamore sawn. Have some elm, wh oak and cherry at the mill now. Wife says if I do not do next winter I am out, well not like that but need to get the 30+ year old carpet gone.

trimguy · March 07, 2020, 12:20:42 PM

Thanks. It is red oak and black walnut. This flooring came t & g on the ends. I did not t & g the cut ends to fit with the herring bone . A little liquid nail. One of my builders likes the floor so much ,that I will be doing one like this in his house also.