Can I place new subfloor (OSB) on top of old vinyl plank flooring and tile for planned faux vinyl tile in mud room?

Question

I know the proper way to do it would be to rip out the vinyl flooring and the old tile and the old plank subfloor and do it properly but bear with me. We have a 1950 house which was originally built as a dance hall (and then moved and added onto).

The original subfloor is wood planks, and then ASBESTOS (4%) tile and then a layer of crappy vinyl fake hardwood T&G added about 10 years before we bought. The previous owner also had a bunch of pets who peed all over the original tile floor so if you rip up the T&G it smells like 80 year old tile and urine. With the vinyl down it smells fine.

I am not ripping out the original asbestos tile and getting it abated (don't have the money or place to live while it's happening). I would rip up the vinyl but then it smells like p*ss and it adds the chance of kicking up asbestos particles. You can see in the picture how dirty and gross the original tile is. That is a section I ripped up to access the tile for asbestos testing.

Is it fine to just add a layer of 5/8 subfloor down as a "fresh start" and to make a nice flat, clean surface?

I am not concerned about height difference between rooms because we are planning to redo the rest of the flooring as well and have to redo all the trim so it will match up.

Answer 1

First, what you are proposing is just the way people have been re-flooring houses for the last 150 years, so the quick answer is yes, you can do that.

Whenever I approach a new (to me) old house project, releveling floors involves ripping old layers and it's always an archaeological expedition of flooring trends, from planks, to linoleum, to hardwood floors, to vinyl rolls or planks, all like a layered cake.

I still want to encourage you to consider removing the old layers, especially if the floor is not perfectly flat and level. In some jurisdictions, removal and disposal of asbestos is pretty straight-forward and safe (as long as you follow precautions), while in other jurisdictions encapsulation (what you are proposing) is the only way without getting costs to spiral out of control.

And like crip659 said on the comments, the urine smell might come to bite you. You'll only know after the project is complete. For me, urine smell on a new floor is non-negotiable. Whenever I work on a house with cat urine smell, I immediately add to the spreadsheet the cost of ripping out the floors.

If your floor is not perfectly level and flat, and of course, depending on the severity, the fix might be simple (a few bags of self-leveler) or more trouble than removing the old layers and sistering the joists.

Oh, and I assume that you have actually sent a sample of the tiles to an asbestos lab. Don't rely on anybody's opinions, the Internet, or what the previous owner said. It's about $20 and you'll know for sure.