How about this solution for uneven floor?


  #1  
Old 10-25-04, 09:18 PM
T
Member
Thread Starter
Join Date: Mar 2004
Posts: 30
Upvotes: 0
Received 0 Upvotes on 0 Posts
Lightbulb How about this solution for uneven floor?

I am tiling a small bathroom and have found the plywood subfloor around the toilet is very uneven (dipping). Since the walls have been installed over the sheets of plywood, I am going to try and cut out the uneven section and replace it with another piece. Or, should I saw as close to the wall and bathtub as possible and replace with cement backerboard or Hardiboard?
Thanks for the help.
 
  #2  
Old 10-25-04, 09:58 PM
COBALT's Avatar
Member
Join Date: Jul 2004
Posts: 168
Upvotes: 0
Received 0 Upvotes on 0 Posts
This may indicate something more serious underneath - possibly water damage from a leaking toilet flange. Do you have access to where the toilet drain comes through the floor from underneath? What shape are the floor joists in? How far apart are they and what are their dimensions? I'd do a good inspection first before just committing to replacing the section, and even if you did that you'd have to block all of the seams, so it could be just as much labor to redo the whole floor, and you'll be happier with the results.

If you have any indication that the subfloor might not be adequate or worse failing then I would recomend cutting the floor out (especially if you don't have access to it underneath) and resheet the floor with some 3/4" tongue and groove plywood exterior grade once the floor joists are reinforced by doubling up the floor joists, and installing headers. Cut the floor as close to the walls as possible, block the seams around the entire perimeter, and cut your plywood to fit. Make sure the tongue and groove seam is perpendicular to the floor joists, and you can block this seam for added strength.

Concrete backer board is not a structural material, but it does resist movement that is common to plywood, but it should only be installed over a plywood subfloor with adequate support. It can't be installed by itself over floor joists. Follow the manufacturers recomended installation instructions - which usually means laying down an unmodified thinset with a 1/4" square notch trowel, and using special tile backer screws every 6-8 inches and 2 inches away from seams.
 
  #3  
Old 10-26-04, 07:22 PM
T
Member
Thread Starter
Join Date: Mar 2004
Posts: 30
Upvotes: 0
Received 0 Upvotes on 0 Posts
It is not a leaking toilet flange, it was the toilet supply line. They shot a nail through it when the house was built and it slowly leaked for 6 years, ruining that part of the floor. I cut out the wall and fixed the leak.

I'm not sure what is meant by "block the seams." I'm thinking I could cut it as close to the wall as possible, lay in some more plywood, and screw it down on both sides of the seams. I don't have access to the joists without cutting out the floor.

Thanks for the good advice.
 
  #4  
Old 10-27-04, 10:25 AM
COBALT's Avatar
Member
Join Date: Jul 2004
Posts: 168
Upvotes: 0
Received 0 Upvotes on 0 Posts
"blocking the seams" means you cut floor joist material to go between the floor joists (perpendicular to the existing joists) or along the floor joists (parallel to the floor joists) that can go under the seams of the plywood. You need something the new plywood can be screwed to, and to add strength to the new sections of floor and strengthen the floor joists across the damaged section, because when you tile you need the least amount of deflection as possible.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: