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Discussion Starter · #1 ·
If your subfloor has a high point in it and it was not found until you lay tiles and notice "hey these are not level". Is it a good approach to peel up the cement board in that area and mix up some bags of Rapid Setting/Level Quick Self Leveling Underlayment


and then pour it in the area directly on the osb subfloor. Let dry and lay tile on top. Is that okay? Just curious

Like this


Thanks,
 

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Did you read the directions?

Primed OSB is ok. Directly bonding to OSB ,not. What they want is a metal lath fastened to the floor then pour over it.

You good?
 

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Flooring Installer
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Did you read the directions?

Primed OSB is ok. Directly bonding to OSB ,not. What they want is a metal lath fastened to the floor then pour over it.

You good?
Metal lath? You mean a Jersey mud job? That is not an acceptable way to install ceramic. They need thinset, CBU, thinset and then tile.
 

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Discussion Starter · #4 ·
Okay I was curious. We poured it directly on the osb sub floor, floated it. and after it dried put down the tile with thinset. and two tiles cracked in that area. I was not sure if it was due to the install procedure or if people cracked it because people were still walking on it while it was curing.
 

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How thick is the subfloor? What are the joists, size, spacing, species and grade?
 

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Metal lath? You mean a Jersey mud job? That is not an acceptable way to install ceramic. They need thinset, CBU, thinset and then tile.
That's not a Jersey mud job. You don'set the tile at the same time.

Customs wants something for the leveler to grab onto. If you were to go over plywood the directions are the same; prime,metal 2 1/2" sq. Lath stapled to subfloor then leveler. You then thinset the tile to the leveler.
 

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Flooring Installer
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just curious what is the minimum joist spacing, grade, species etc to install tile over? Thanks
My main concern would be that the subfloor is not thick/stiff enough for tile. You need two layers with a total of about 1 1/4".
 

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Flooring Installer
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The john bridge forum has a chart you can use to determine if your floor is stiff enough.
 

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Head Light Bulb Changer
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I don't care what anybody says - You can NOT lay tile directly over wood. Maybe in a select few applications (ie perfectly stable moisture levels), but I still wouldn't do it. Mud bed with lath doesn't count as directly over wood.
 

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I don't care what anybody says - You can NOT lay tile directly over wood. Maybe in a select few applications (ie perfectly stable moisture levels), but I still wouldn't do it. Mud bed with lath doesn't count as directly over wood.
Sure you can. I pull tiles off of wood all of the time and some are 30+ years old. I wouldn't do it, but you can.
 

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I agree that tile can be done over wood. I've never done it, but it can be done. The same problems occur that the poster has experienced. You don't want to lay tile on 3/4" subfloor, but if the floor is thick enough plywood will work.
 

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Discussion Starter · #20 ·
I agree that tile can be done over wood. I've never done it, but it can be done. The same problems occur that the poster has experienced. You don't want to lay tile on 3/4" subfloor, but if the floor is thick enough plywood will work.
Oops sorry for the confusion, That is durock underneath that tile and where you see the rapid set was a high point in my floor joists so we peeled up the durock in the section you see. Mixed up rapid set and poured it and floated it between the durock sections.
With that being said is that acceptable?

Thanks,
 
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