Install Plywood Subfloor Over Old Vinyl Which Is On Slab

Hello,

My wife and I bought an end-unit town house built of cinderblock (in 1937) and with concrete floors. We want to install prefinished 3/4" solid white oak flooring strips from Harris-Tarkett. I am starting with the smallest bedroom. This room has carpet over carpet padding which is in turn over very old vinyl tile. This tile, in turn, is laid on top of an old black-colored tile containing asbestos. The black colored tile is over concrete.

During carpet tack strip removal both the vinyl and black tiles proved to be quite brittle and pieces of them broke off the floor.

I want to vacuum clean the top layer of vinyl, dispose of all the broken tile pieces, pull out all the staples which are stuck into the vinyl from the carpet padding, and then install a plywood subfloor over this so I can install the hardwood strips on the plywood.

I think I should attach the plywood directly to the tiles and concrete using a pneumatic nailer. What do you think of this?

I'm also stumped on how to get this floor level. The floor is definitely not level. There is a high spot in one corner.

I have looked at Greg Warren's photo presentation that Piru was referred to. But it looks like Greg didn't have to worry about leveling the slab floor and it was bare concrete to begin with.

I have done general construction but never installed a hardwood floor before. I bought Don Bollinger's book and have read it. His examples focus on a house with wood 'car decking' for the subfloor, not on a concrete floor.

What is your advice?

 

Bob:

I may be looking at this wrong but here goes. Staples in old vinyl tiles over concrete? I hope someone else can chip in here, because I don't have much knowledge on going over such conditions. Asbestos for sure.

How high is that spot in the corner compared to the rest of the subfloor? Don't confuse level with overall flatness, as that's the key for the most part. Use a string line to check.

Have you considered a floating engineered floor? It may help to eliminate alot of problems associated with the condition of the subfloor. Try this reading...

http://www.hoskinghardwood.com/starthere.html

Good Luck

 

My "gut feel" for this one is, most likely there is asbestos, and you would be wise to either encapsilate the asbestos or engage an asbestos removal contractor. If it is asbestos and it stays, you are required by state law in many if not most states to disclose this fact when you sell.

[Edited by AzFred on 09-06-01 at 04:58]

 

http://www.epa.gov/iaq/pubs/asbestos.html

 

Thanks for your help folks. Ken, I will check the floor soon to find out how high the high spots are. I believe there are a few high spots but need to confirm that. I have one room almost decently clean now and free of staples and nails. The staples are driven into the vinyl tile, not into the concrete. I pull them up with wide pliers.

We already bought 3/4" solid white oak flooring from Harris-Tarkett.

We know the vinyl floor "black tile" tiles contain asbestos. I do not feel concerned about this because a new subfloor should contain the asbestos. EPA says just leave it there.

I will get back to you Ken.

Thanks!