robbinPremium,MVM
join:2000-09-21
Leander, TX
kudos:1 | reply to jjoshua
Re: Pop from tile floor That part of the floor needs to be torn out. The crunching you hear indicates movement and that part of the floor will slowly disintegrate. Every time it moves a little more will break.
Question -- did they "bond" the cement board to the subfloor with adhesive or did they just nail it? |
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 jjoshuaPremium
join:2001-06-01
Scotch Plains, NJ
kudos:1
4 edits | said by robbin:Question -- did they "bond" the cement board to the subfloor with adhesive or did they just nail it? I pulled up a threshold to check. There is actually 3/8" plywood over the subfloor and the cement board is adhered to the plywood (it looks like they used mastic). I recall seeing nails in the cement board before the tile was installed. |
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robbinPremium,MVM
join:2000-09-21
Leander, TX
kudos:1 | First problem I see -- as far as I know 5/8" subfloor is the minimum suitable subfloor for installation of cement backerboards. Personally I wouldn't use anything less than 3/4". I also don't like using mastic to bond cement board but if they used the proper mastic it probably meets spec.
The 3/8" subfloor could be causing problems as it is too thin and flexible. Cement board provides a good bond surface but in itself adds no strength. There is going to be movement inherent in this installation due to the thin subfloor. |
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jjoshuaPremium
join:2001-06-01
Scotch Plains, NJ
kudos:1
1 edit | said by robbin:The 3/8" subfloor could be causing problems as it is too thin and flexible. Cement board provides a good bond surface but in itself adds no strength. There is going to be movement inherent in this installation due to the thin subfloor. The 3/8" plywood is over the existing diagonal plank subfloor. Check out the pictures in the link. Are you saying that even that is not enough? |
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robbinPremium,MVM
join:2000-09-21
Leander, TX
kudos:1 | Correct -- it should have been 3/4" over the diagonal subfloor. Basically tile installation specs don't allow for 3/8" as a subfloor material no matter what it is over. |
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 PeeWeePremium
join:2001-10-21
Madera, CA
1 edit | said by robbin:Correct -- it should have been 3/4" over the diagonal subfloor. Basically tile installation specs don't allow for 3/8" as a subfloor material no matter what it is over. The diagonal material is sub-floor the 3/8 material would be called underlayment and can be any thickness. The purpose of underlayment is to eliminate voids and give a smoother surface (as in non-structural).
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My grandkids REALLY ARE cuter than yours! |
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robbinPremium,MVM
join:2000-09-21
Leander, TX
kudos:1 | I take it that you are a Tilesetter. Please provide reference and proper specifications allowing this practice. Specifically where does ANSI (American National Standards Institute), TCNA (Tile Council North America), or any other standards institute allow this practice and under what conditions and installation methods? |
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PeeWeePremium
join:2001-10-21
Madera, CA | said by robbin:I take it that you are a Tilesetter. Please provide reference and proper specifications allowing this practice. Specifically where does ANSI (American National Standards Institute), TCNA (Tile Council North America), or any other standards institute allow this practice and under what conditions and installation methods? Pass. Find out what you're talking about first. When you find out the difference between underlayment and sub-floor, then we can talk.
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My grandkids REALLY ARE cuter than yours! |
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robbinPremium,MVM
join:2000-09-21
Leander, TX
kudos:1 | I know what I am talking about. The CBU (Cement Board Units) are the underlayment. There is no specification which allows CBUs to be installed on another underlayment, they are to be installed on a subfloor. The 3/8 is either a second underlayment which is not permitted or it is a subfloor in which case it it too thin.
In either case, it is a substandard installation which does not follow proper tile installation procedures and techniques. This is the reason for the current problems. The floor is almost new and the issues will only get worse over time. |
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PeeWeePremium
join:2001-10-21
Madera, CA
1 edit | Go back and read some more, properly attached underlayment is allowed. Most often the thickness is determined solely to set elevations as needed. I really wish you didn't see this as a competition.
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My grandkids REALLY ARE cuter than yours! |
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 chmodPremium
join:2000-12-12
Lockport, IL | reply to PeeWee
said by PeeWee:said by robbin:Correct -- it should have been 3/4" over the diagonal subfloor. Basically tile installation specs don't allow for 3/8" as a subfloor material no matter what it is over. The diagonal material is sub-floor the 3/8 material would be called underlayment and can be any thickness. The purpose of underlayment is to eliminate voids and give a smoother surface (as in non-structural). While I agree 3/8 apa rated wood underlayment gapped an 1/8" on long and butt seams is a acceptable substrate to put tile down on, I dont think I would put that over dimensional lumber ie 1x's on a 45 (which my house has). Also, no matter how many layers of underlayment + subfloor you have I wouldn't use anything less than 3/8 for a ceramic install. We use 1/4" hardibacker for fireplace surrounds but high traffic floor areas 3/8 to 1/2" apa rated plywood glued and stapled every 1.5inches on the perimeter of the sheet and 4-6inches in the field.
I don't claim to be a ceramic guru by any means more vinyl than anything. But I install a lot and I mean alot of underlayment for ceramic crews for one of the stores I work for. As for 3/8 or 1/2 like you mentioned it depends on the product its mating up against to. 3/8 for hardwood installations makes a smooth grouted transition. 1/2 is used more on second floors in new construction when going up to carpet. I'm sure I'll get crap because the store I work for one of the largest in will co. and other members have posed about here use apa rated wood underlament for ceramic on most new construction and retail.
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Some people are like Slinkies. Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs. |
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