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Best Way to Level Sub-Floor


mossman's Avatar
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09-11-10, 08:09 AM   #1  
Best Way to Level Sub-Floor

I'm renovating my master bathroom and the floor is un-level. I will be setting a shower pan and separate bathtub in these un-level areas. I plan on laying an additional layer of plywood (5/8") to the entire bathroom floor first. What is the best way to level the floor? Should I install shims between the existing floor and new subfloor, or just shim the shower pan and bathtub after the new subfloor is laid?

 
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09-11-10, 06:01 PM   #2  
Picked up a bag of self-leveling mortar today. I plan on pouring the mortar where the tub will be installed only, then installing 1/2" plywood throughout the remainder of the bathroom with 1/4" cement board (Hardybacker). This will not only give me the support I need for ceramic tile, but will also give me the height I need to hide the 3/4" gap that is going to exist between the tub apron and existing subfloor due to leveling.

 
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09-11-10, 06:12 PM   #3  
Is there a question here..?? - needing some assistance..? - or just letting us know what you're doing.??
.

 
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09-12-10, 10:15 AM   #4  
Question is in the original post. Second post was a follow-up. Sorry, it won't happen again.

 
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09-12-10, 10:32 AM   #5  
No worries.. maybe I missed it..
Your 2nd post seems to be the way to go...

 
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09-13-10, 04:10 PM   #6  
Self-leveling mortar did not work, for a reason I don't know. Is it possible I poured it wrong? It filled in nicely (only poured a 3' x 5' area), and everything is consistently flat, but it is still un-level. Unless my house settled 1/2" overnight, then I'm baffled. Now I still have an un-level floor, only 3/4" higher than it originally was. Guess I'll be shimming the tub after all.

One thing I didn't do was apply the latex primer to the wood subfloor before application. Is it possible that the plywood sucked some of the moisture out of the leveler and prevented it from spreading as it should? I'm really baffled (and pissed) as to why it didn't work.


Last edited by mossman; 09-13-10 at 04:13 PM. Reason: Added Comments
 
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09-13-10, 06:40 PM   #7  
When you use slc, you have to use the primer and lathe over a wood subfloor. Additionally, you have to plug all holes, use self stick insulation around the wall edges and plug anyplace that the slc can seep out of. Im not sure what went wrong since it didnt work for you. It should level pretty good on its own, maybe needing a little help at the edges. Did you read and follow the manufacturers instructions?

 
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09-28-10, 03:41 PM   #8  
Used it again for under the shower and same thing, didn't level the floor. I used primer this time and there was no seeping. Think I needed to pour a little more, but ran out. Not a big deal. It's pretty level and I'll be setting the shower pan in mortar, plaster, etc. anyhow.

 
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