Replies

1. 
   BobKovacs | Oct 10, 2003 06:20pm | #1

   Use enough construction adhesive and it probably won't be a problem.  But, if you want to fix the situation, get a power planer and plane the joists flush.

   Bob

1. 
   UncleDunc | Oct 10, 2003 06:59pm | #3

   Or shim the short ones.

   Edit to add: You might want to take a moisture meter to them. It could be that the tall ones just aren't as dry as the short ones and when they all dry out they'll be the same size. In that case, neither planing nor shimming would be a good idea.

   Edited 10/10/2003 12:07:06 PM ET by Uncle Dunc

2. 
   Porsche998 | Oct 10, 2003 07:12pm | #4

   I plan to use adhesive and 1 1/2" screws.  I thought that there probably would be no problem but wanted to check on experience of others

   Edited 10/10/2003 12:20:31 PM ET by Ron

1. 
   Tryit | Oct 10, 2003 09:50pm | #5

   Boy an 1/8 of an inch seems like a lot.  You screw that down and the subfloor would taper that gap in . . . what . . . 6 or 8 inches?  If that is in the middle of your room and some of the joists have this gap and some don't and you put carpet over it ... SO WHAT.  Hardwood floor over it?

   I am not a hardwood floor man, but as a novice that would make me cock my head.

2. 
   woodguy99 | Oct 10, 2003 10:09pm | #6

   I echo the moisture meter advice. If the joists shrink differently you'll have squeaks, construction adhesive or not.

3. 
   jonblakemore | Oct 10, 2003 10:46pm | #7

   What is your subfloor thickness?

   If you are going with 3/4", I would recommend a longer screw.  This would be especially helpful when you are screwing the ply to joists adjacent the tall ones.  Assuming the moisture content of the pieces is where the difference lies, when the tall ones dry out they should even out and you will have a reasonably flat floor.  Or the joists could just be different heights, in which case the longer screws will ensure that the ply bears on each joist. 

   Jon Blakemore

2. 
   stossel1 | Oct 10, 2003 06:52pm | #2

   To avoid this in the future use TJI's.

3. 
   mike4244 | Oct 10, 2003 11:15pm | #8

   Ron, I am assuming this is a new house or addition. Your joists are drying out, they will shrink much more. Slight differences between joists are not a problem. You may have a problem if the joists are framed into the beam and the beam is a different material. Steel or laminated beams won't shrink, if your joists are wood they probably will shrink an average of 1/2" in depth.You would be a 1/4" low after one heating season, the joists will shrink evenly from the center of the depth to the top and bottom of the beam. Framing lumber is 19% allowable moisture, used to be 12% when my hair was blonde.If you want a perfect floor for the future, rip a sheet of 1/2" plywood for the width of the beam and nail that on. Make sure the finish floor ends do not end up on the 1/2" rip.