[Allie Em]

Wondering if anyone can share some advise on using Ditra with thinset after removing vinyl sheet flooring where the paper backing is still attached pretty darn good to the plywood subfloor.

While removing the sheet vinyl, the green paper backing seperated from the material. We are scraping off as much as possible, but it is still stuck to a large percentage of the plywood.

Our concern is whether the thinset will soak into the paper and make the Ditra fail, or if it will work just fine.

Thank you for any advice or information you can share. :vs_cool:

 

[JazMan]

Vinyl flooring is not glue to the subfloor, it's glue (usually) to an ¼" underlayment which is stapled to the subfloor. You remove this ¼" ply or OSB and if in good condition, Ditra is installed to the subfloor. Tell us what layers you've got and their thicknesses. Also need to double check that the framing is strong enough for tiles so...... the size of the joists, spacing and span of the shortest joist. Do you know the species and grade? Basement or crawl? How old, etc.

Jaz

 

[Allie Em]

JAZ!!! Your reply was just what we needed! It made us newbies take a closer look at everything and we found that it wasn't glued to the sub floor, but to the top layer of plywood. There are two layers of 3/4" plywood nailed down.

I am thinking that the best bet would be to remove the top layer as it currently is level with the 3/4" oak that adjoins it.

Any recommendation on the best method to separate the nailed layers with that thick of board? Is there a chance, based up a guesstimate, that with the highest quality of work being put into this house back in 1970, that the two pieces of plywood might be glued together and we're opening a can of worms with trying to remove one layer?

Any thoughts would be greatly appreciate. Again, thanks for your awesome reply. We did look at the basement rafters and everything is solid there too.

 

[JazMan]

Allie,

In my reply above I meant to say " span of the longest joists" not the shortest. You avoided the subject of the framing though. When you say We did look at the basement rafters and everything is solid there too. Actually that statement means nothing.

So, you confirmed that both layers are ¾" plywood and the subfloor is "subfloor grade" and is t&g, right? Can you see markings from the basement?

The two layers of ply should not be glued together, (just the subfloor should be glued to the joists), but who knows.

Do not remove the top layer until you know the subfloor is t&g and in your best guess it's in good condition.

If you keep the top layer, you'll want to get that felt backing off and get down to clean wood. Otherwise it would be safer to add ⅜" (min.) underlayment + Ditra or switch to concrete backer instead of Ditra.

Go measure the joists and post later. Pics are nice too.

Jaz