What to do about removing old tile masti
In a remodel, I have to take up a bunch of floor tile, linoleum, and carpet and replace the entire thing with hardwood. The carpet is easy. The linoleum left some junk on the plywood subfloor but I think I can deal with it. The tile left a war zone of old dried mastic. I’m thinking about renting a floor sander to remove the mastic or just replacing the subfloor.
Is either idea right? Is there a better way?
Purgatory Red
Replies
All of the finish products you mention; tile, carpet and linoleum, should have been installed over underlayment, not the subfloor.
So at this point I get a little confused because you mention wanting to install hardwood which would go on top of the subfloor AFTER all the underlayment has been removed.
So where is the tile mastic? On the underlayment or the subfloor?
It's Never Too Late To Become
What You Might Have Been
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Like Eric said, usually U can just pull up the underlayment. Usually it is 1/4 to 1/2'' stuff. Beats scrapin
When in doubt, get a bigger hammer!
Why underlayment? What purpose does it serve?
Around here where all the houses are built with I-joists and 3/4" T&G subfloor, almost everything goes right down on the subfloor.
I can think on one exception. Sometimes Hardi backer is screwed down under thinset to bring thin porcelain tile up to 3/4" hardwood floor or thicker slate tiles.
Chris
What can I say, I'm old school and I still think two layers is a better end product.
BTW, I was only asking the OP as it was unclear by his post.
Perhaps his post is another good reason for two layers. Yo can always remove one if it is comprimised.
Not trying to start a flame fest, just my opinion.It's Never Too Late To Become
What You Might Have Been
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Hi Eric,
No flame intended at all. I was truely interested in why you think an underlayment is needed in most cases.
Chris
Almost all the flooring remo jobs i've done have had underlayment.
Not saying that none have been done without.....or that it is absolutely nesesary, but most manufacterer's recomend it.
I'm talking vynel (sheet goods) flooring, and ceramic definately does require it.
Whenever we put in hardwood, we just do membrane, and nail right over the subfloor.
And if you're tearing out them old vynel tiles, it sure is easier to just get under that underlayment and get it all out!
When in doubt, get a bigger hammer!
I must be using the wrong words.On the floor joists is a single layer of 3/4 inch plywood. Nothing else. The mastic is on the plywood.Aside from reminding me my terminology is wrong, your note implies I may need another layer of what I've been calling subfloor.Would you expand on that thought please?
I've also seen at 3 different homes (I've owned or worked on) a double layer of subfloor, usually two layers of 5/8.
Putting a new layer of wood would give you a more solid surface AND save you from the chemicals or grinding.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Flooring ststems in residential homes typically, but not always consist of two layers of flooring attarched to the floor joists. Typically the flooring system will add up to a total of around 1 1/4" in thickness.
The first layer on top of the joists would be the sub-floor and might typically consist of 3/4 toungue and groove in some older homes, or 1/2" or 5/8" CDX ply wood.
Now ontop of that would go the finish floor consisting of perhaps hardwood flooring, or a layer of substrate or underlayment specified for the installation of vinyl flooring or perhaps ceramic tile.
Typically if vinyl flooring is spec'd, then this layer might be 5/8" or 3/4" AC plywood or possibly Medium Density Fiberboard.
Same would apply for ceramic or stone but one would not use MDF in this instance.
There are newer products on the market now where it is possible to install just one layer of flooring around 3/4" or greater and then carpet or tile may be installed over it.
I would NEVER, EVER install ceramic or stone over a single layer of subfloor less than 1" thick.
There are other products too that may be installed over the subfloor to facilitate the installation of ceramic or stone, these being a cement board about 1/2" thick. There is also a product known as Hardi Board.
I typically stay away from both of these products for use in flooring applications for tile and stone installs as I believe they add a lot of weight while not providing the structural integrity that is gained from the use of another layer of plywood instead.
One should always strive to have all the finish floors be of equal height in a home, and to try to eliminate the need for reducers and saddles to compensate for the lack of forethought and creativity.
That should answer your question about as clear as mud.
EricIt's Never Too Late To Become
What You Might Have Been
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I completely agree with Eric, and would go so far as to say the ideal height should be 1 1/2". That's because a 3/4" subfloor with a 3/4" hardwood floor = 1 1/2". That's the one product you can't 'change'. So then all floors should shoot for that height; ceramic should be 1/2" CBU with a 1/4" tile on top. Vinyl should be 3/4" BC underlayment (rated as such), NOT LUAUN!!! And carpet should be 1/2" ply (not particle board as we did in the past) so that the carpet actually will be above the other floors until it is walked on and compressed.
While there is no law saying these are written in stone, it does serve as a great start for all of us to try to follow. What do you think?
Eric,I pretty much figured you would reply along those lines.In the present case, I have 3/4" plywood on the joists. On that there was carpet, linoleum, and tile. Taking the tile up left a mess of mastic. Someone suggested the mastic might be water soluble. I’ll try that. If that fails, I’ll replace the subfloor. Either way, I’ll add a ½” underlayment. In the process, I’ll replace the present nails with screws.I thank you for your advice.
I recently had to do this on a basement reno. Old tile directly on slab on grade. Initially I used demolition hammer with special tip for removing tile. Tiles came off easily but did a patchy job of removing mastic. I tried a big floor sander but it was very slow, not to mention some broken belts. In the end I put on the knee pads and used an 8" angle grinder with an abrasive cup. Needless to say a respirator was required, and there was a lot of dust, but it was faster than anything else I tried. I got the floor flat enough to install 3/8" plywood subfloor prior to hardwood.
thinset or mastic? Mastic will gum up a floor sander pretty quick spend half the day dealing with that, I would advise against it on thinset ( cement, abrasive, lots of dust, youare doing a remodel right.) same with a 8" grinder with a floor cup wheel on it, although the grinder is my choice if given an option. Some roofing scrapers and the two foot long handle scraper work well, dont bother with the razor blade type for the majority of the floor, corners it works ok.
If you are going hardwood, can you skin the floor with 1/4 to 1/2 ply? (Final floor thickness issue) If so go to town with the demo and squirt some big zigzags of PL glue and screw it down. (helps stiffen a spongy floor too.)
BTW, I hate mastic!
I had to pull up some resilient vinyl from a utility room before putting down tile. The angle grinder worked, but was ugly and messy.
I ended up using a heat gun and scraping it off, but it was *very* slow going.
Since you have no profile information I can't tell where you live nor how old the house you are working on, but here is a warning:
Tile Mastic can contain asbestos. If you don't know its not asbestos - DON'T GRIND IT!
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
For mastic, contact Franmar and ask for a sample of their soy mastic stripper.This is what we used to get rid of the black mastic on our basement floor. It's an amazing product, albeit a bit messy.It's completely Soy based, so it's non-toxic and completely safe to use. You just poor it on, scrub it a bit, then let it sit for a few hours, then just squegee it off.The drawback is that it's messy...once you get some on the mastic, it will never 'dry' again, so once you commit, you got to get it all off to keep from having a permanently sticky floor.I'm not affiliated with the product at all, just really really impressed with the product.
Thanks, I need to check that out.It's got to be better than covering the floor with rags and soaking the floor in mineral spirits.Anything has to be better. That's the kind of idea that causes insurance agents to produce a surplus . . .
First, try a little water on some of the old adhesive. Amazingly, some of the old ones were water soluable.
If that doesn't work, just chip off the big chunks, rough sand, and cover the rest of the sins with new underlayment.
-- J.S.