After being out of the trade for 15 years, covid has my current business shut down, so it’s back to the old days. I was asked to tile a floor for my neighbor’s friend at their beach cottage. It is a cottage about 60 years old and unheated in the winter. They had picked out and purchased the tile, I would have recommended something else but a moot point at this time. The tile is 1’x2′, about 3/8″ thick. Right now there are glue down commercial type 1’x1′ flooring squares. There is a 1/4″ plywood subfloor under them, and when I started to pull the old subfloor under the flooring, found that it had been installed over 9″x9″ glue down (probably asbestos) tiles glued with a black tar like substance. The subfloor under that is 2 1/4″ tongue and groove oak hardwood that was nailed directly to the joists with no subfloor under it. The joists are real 2×8’s spaced 16″ on center with just under a 12′ span. Not having tiled a floor in about 20 years, things have changed a bit.
The temperature swings are a bit of a concern, and I can’t glue down a membrane to the first layer of glued down flooring tiles I don’t believe. Do I pull the 1/4″ ply subfloor and use a cement board type subfloor or put down ply again? Should I install a membrane over it? Height is a bit of an issue since I am already almost a 1/2″ above the floors in surrounding rooms. I wouldn’t be so concerned if the tiles were smaller, but they went ahead and bought them without consulting anyone – my neighbor did tell them NOT to use tile though. My big concern is the cracking of the tiles given the temperature swings and size of the tiles. 🙁
Any suggestions from people smarter than me would be greatly appreciated.
Replies
First, find out what the tile manufacturer's floor deflection standard is, and verify the floor meets it. If it doesn't, cracking is nearly certain. I've done this with a laser and a point load of something like 300 lbs.
Then read this article: https://www.finehomebuilding.com/2017/05/09/laying-large-tile
I photographed and edited that, and the author really knows what he's doing.
What Andy said.
Clients always complain about floor heights and transitions. You need to prioritize proper installation as more important than floor height. Otherwise, you'll get complaints about cracked tiles. That complaint will cost you your money - even if they sign a "waiver". Poor craftsmanship/ incorrect installation is not absolved by a waiver in the courts.
Frankie
Hopefully I'm not breaking any etiquette rules by suggesting this but you should ask about this on the John Bridge tiling forum: https://www.johnbridge.com/vbulletin/index.php They deal with these kinds of questions all the time and will probably give you good advice specific to your situation.
You break no rules.
John Bridge is a good referral for quality information and often, advice.
Thank you, I'll try there.
Tell them the tiles will crack.
sounds like too much build up (to me), since there's no saving the oak flooring for future use, I'd pull off everything down to the joists and start over with a new subfloor (3/4 advantantek with their can gun foaming adhesive ?) - lot of work but you'll have a stable level surface, you'll be able to match the flooring heights, use new methods for installation and ultimately have a happier client (and probably a happier you since you won't have to worry about the floor failing) and... as an extra, you could suggest adding a electric floor heating system under the tile so the cabin could be used earlier in the season and later in the year
good luck