I put a eastern white pine subfloor into my timberframe this summer. The wood was well dried, according to my moisture meter they were less than 10% and most were 8% .
I used a bar clamps to ensure everything was a tight as could be . Now, in the middle of the winter some of the boards are as much as a half an inch apart! (average of 3/8ths) the boards are 8 inches wide and two inches thick. Some are tamarack but the shrinkage seems the same wiether it’s pine or tamarack.
is this normal shrinkage?
Replies
It does seem excessive -- has there been any cupping/warping?
IanDG
flat as a board, er pancake...
What does the moisture meter say now? My first guess would be that the meter was lying to you about the moisture level in the middle of the boards.
less than 6%! The funny thing is the 2 x 12's I put down last year have a very small gap! (less than an 1/8th) they were from the same batch of wood.
The beauty of wood!!
Hello
the wider the board the more it will expend and contract. I normaly try to cut my boards into 3" peices and then eather glue them back to gether or not to relive this problem.
since the boards are all ready down. you can use a old navy trick.
weage a small peice of rope (natural stuff like hemp, not nylon )into the gap, it acts like caulk to fill the gape, the rope will expands and contract with the boards. it should keep things tight.
also keep the boards oiled or sealed may help.
C.A.G.
Luckily for me, these are sub floor boards and so they don't need to be tight. I was gonna wait for a while before putting the finish floor down to see what happens to these in the summer.
Frenchy, with 2 inch boards, is it possible that they were wetter than 12% on the inside and that you meter was measuring too close to the surface? I know that you used some of this stock before but maybe the stack had gone through a period of high humidity and was begining to dry out again. Just a thought.
BJ Gardening, cooking and woodworking in Southern Maryland
Most likely you are correct. I foolishly asumed that since they were fine a year before, they would be evan better a year later.... Backed up by a meter reading but you are correct. ####-u-me.
"------Luckily for me, these are sub floor boards and so they don't need to be tight."I'd be worried what that sort of seasonal movement is going to do to the hardwood flooring above. IanDG
That's my concern too!
A form of floating floor, perhaps?Another alternative would be to nail the hardwood flooring (unless you're going to use laminate, of course!!) only into the center of each sub-floor board so shrinkage movement wouldn't have any effect on the overlay floor.IanDG
Edited 12/28/2002 11:08:46 PM ET by IanDG
Frenchy, I'd bet that now you have them down and they have dried in place and I assume that they are equilibrated to the house interior, that they arn't going to move a whole lot anymore and that your hardwood floor can go down over them with out any worry about sub floor movement.
Come to think of it, when I worked with Dad in the 40s I used to see the diagonal laid subfloor shrink a lot like yours and it never seemed to affect the t&g oak flooring laid over it. I think you're in good shape here.
BJ
Gardening, cooking and woodworking in Southern Maryland
Edited 12/28/2002 11:45:40 PM ET by Bee Jay
Frenchy, If you made a mistake, I think that it was the mistake of not using elm flooring. (grin)
BJGardening, cooking and woodworking in Southern Maryland
I hope so, I'll keep track of the movement over the next year and if it's relatively stable I'll go ahead, if not, tell me how do you pick up a timberframe to put a new floor under it? anybody got superman's phone number?
frenchy
Have to agree with Bee Jay on the fact that you can have a big variance at the ends of your stock as opposed to the center. I use a lot of yellow pine for tool stands. A typical 8' or 10' can be 12% at the ends with a digital meter which measures to about 1/2" deep. In the center of the board it can measure to 18% or better. I precut them to a little longer than I need, clamp them down and let them stabalize in advance of use.
Also agree with Ian on what could happen down the road to the actual dress flooring with that kind of movement going on underneath. Since thery are already down, you might try the Navy trick posted earlier to help check further movement.
Good luck with your venture...
sarge..jt
Flat sawn. (most, a few wind up being quarter sawn...) typical mill run stuff.
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