Replies

1. 
   woodguy99 | Sep 10, 2003 11:57pm | #1

   Ouwins,

   It's usually a good idea to run sistered floor joists as long as you can, ideally all the way, but if you can't, just use a lot of connectors (ideally, thru-bolts) near the free-hanging end and others spaced along the length of the joist.

   The subfloor should all run in the same direction, but offsetting the joints is a good idea. Make sure the butt ends land on a floor joist, though.

   Our tile sub counts his backerboard as part of the subfloor; are you sure you need a full 1 1/2" of wood?

2. 
   Piffin | Sep 11, 2003 12:03am | #2

   When you say "old termite damage" does that mena that you are absoutely certain the old buggers are all dead and gone? I wouldn't want to leave any tunnels or nests behind by sistering when I can replace them.

   Yes, do offset plywood joints as you layout, but I'm agreeing with Mikers statement, som,e primadons tile guys want all three layers but many will set over two of ply without backer. A lot depends on the type of tile. Slate is big and brittle so that may be the reason for needing extra backing.

   .

   Excellence is its own reward!

1. 
   ouwins | Sep 11, 2003 12:30am | #3

   I need the 1-1/2" to match the floor elevation in the adjoining dining room which will have the same slate floor.  I did not find any signs of current termites but I am having a pest guy look at it tonight just to be sure. 

   As for sistering the joists,  my plan was to nail 6' of 2x10 to the old 2x10 joist and also to install 2x10 blocking between joists for 2-3 spaces on booth sides of the sistered joist.  Replacing the entire joist would mean moving ductwork and plumbing lines, something I would like to avoid.