Replies

1. 
   calvin | Jun 16, 2010 09:59pm | #1

   shims of some sort

   Assuming that you don't need to deal with the framing (broken, misplaced or "other"-joists.............

   shim it.

   Use wide wood shingles, 1/4" ply, asphalt shingles, tar paper, whatever you got to bring it close to "FLAT".

   You level shows the floor is not level-and trying to make it such might be too much for the job or the installer.  Find flat.

2. 
   xxPaulCPxx | Jun 17, 2010 01:29pm | #2

   Why no SLC?

3. 
   DanH | Jun 18, 2010 10:39pm | #3

   You leave out several critical pieces of information:

   -- What's the floor construction?

   -- What will be the new floor covering?

   -- Why not use leveling compound?

1. 
   DonnaJim23 | Jul 13, 2010 04:22am | #10

   You should use leveling compound, that's very important!

4. 
   SquareStraightLevelPlumb | Jun 22, 2010 05:16pm | #4

   How to level floor...

   Ditto on shooting for flat rather than level.

   First, what caused the dips?

   I ran into a wavy floor on a major renovation / addition project.  The framing was done with pressure treated lumber.   The girders and floor joists had shrunk differentially.  The floor sheathing was diagonal pressure treated 1" pressure treated lumber.  The existing floor was sound, just not flat.

   Before we installed 8" heart pine flooring in this large room, we had to level the floor.  The best method that I could come up with was the following.

   We glued and screwed layers of 1/4" everywhere there were dips in the floor and then removed the screws.

   Anywhere the dip was over 1/4" we glued down a second layer.

   Anywhere the dip was over 1/2" we glued down a third layer.

   Then we rented a commercial floor sander and sanded the edges of the plywood down to 0 and levelled the floor that way.

   This was a lot of work, but provided a very good nailing base for the pine floor, which we would not have had with any kind of levelling compound.

   I consider this a "best practice" solution.

   Be sure to think through the transitions at all the doors!

1. 
   navrescarl | Jul 05, 2010 06:33pm | #6

   uneven floor

   In your advise you said the following:

   We glued and screwed layers of 1/4" everywhere there were dips in the floor and then removed the screws.

   Anywhere the dip was over 1/4" we glued down a second layer.

   Anywhere the dip was over 1/2" we glued down a third layer.

   What did you use in the layers?

   I have on my floor is 10x10 joist that are bowed at places and the floor is OSB.  There are places where settling occured and the OSB close to the load bearing wall is where most of the settling is.  

   I now that leveling compound becomes brittle when you nail into what else can I use?

1. 
   Clewless1 | Jul 10, 2010 11:38am | #7

   What is the flooring you want to install? Assuming it is e.g. wood flooring, it shouldn't matter. Even if the leveling compound cracks a bit and such, it's not going anywhere ... it is still doing it's job of providing a flat base under the flooring.

   Nailing through leveling compound doesn't 'create' a more brittle material (i.e. it doesn't change the composition or properties of the material just because you are nailing through it).

   Not sure what you intended to show w/ the pic. It doesn't seem to illustrate much other than the other floor is maybe not level.

   I agree w/ others ... flat is important ... level not so much so (generally speaking, of course).

5. 
   mikeroop | Jun 26, 2010 11:32am | #5

   why not leveling compound?

6. 
   Piffin | Jul 10, 2010 04:58pm | #8

   subfloor that extreme is a framing problem

7. 
   junkhound | Jul 10, 2010 08:29pm | #9

   Uha, duh..

   Ya lower the high spots and raise the low spots to make it flat. 

   Then put a level on it, and raise the low side and lower the high side to make it level.

   Whut cud be simpler? 

8. 
   cgreene2 | Dec 21, 2011 02:45am | #11

   Jacking spots can be tricky based on which way the low spot runs in relation to the direction of the joist.  It can be successful if the low spot runs in the same direction as the joist.  Wnen the low spot runs perpendicular to the joists, jacking the joists can raise the whole low spot area - including the surrounding high spots.  Sometimes after trial and effort the best solution is a self leveling patch compound.