The adhesive may emulsify in the presence of hot water. If it is a hydrocarbon type, then the water will have no effect.

Be aware that any solvent you may use in your attempt to soften the adhesive will drive the adhesive deeper into the wood fibers.

Use mineral spirits to soften the mastic and scrape off all that you can. You should be able to get enough off to then be able to sand the floors. That's when the asbestos concerns come into play.

Mineral spirits won't drive it into the grain.

"Mineral spirits won't drive it into the grain."

Mineral spirits will easily carry the color deeper into the wood.

What's your suggested solution, brickeyee?

While we wait for brickeye's response, a solvent will drive the adhesive residue deeper into the wood, which will require a deeper sanding to get beneath the resulting stain.

Best way to handle this is to hire a professional who can remove this for you. If you insist on DIY, then slice off all you can with a sharp razor scraper and then be prepared to sand the rest of it off.

If you have access to dry ice and good, thick gloves to protect your hands - you can place the dry ice on a small area of the mastic at a time to freeze it, then rap with a hammer to shatter the mastic, sweep it up, move on to the next spot. You will still have to use sand or use solvent to remove whatever remains.

You need to have the mastic checked for asbestos content before trying dry removal methods.

Dry ice works sometimes, or just heavy sanding with a drum sander (and a lot of paper).

If you use anything liquid the material can move deeper into the wood, and WILL move into the cracks between the boards.

When you then sand the edges of every board can show staining.

Finishing with any traditional solvent based stain or urethane will wick out remaining mastic from between the boards. I would only sand it or scrap it off.

Hey buddy.. ok I actually have a great answer for you... idk and what these others are thinking.. but ok... Google diamabrush removel tool... home depot rents them... that will do it easy.. no issues... I know because I have exact same issue and takes it off easy and painless.. leaving perfect hardwood ... I hope I tool some stress away and made your day.. I know it was a hard road for me to get this answer for myself haha... tried all the crap others said.. nope waist of time...sorry... diamabrush removel tool.. in details it describes removing black mastic such as ours..:-)

Never seen or heard of "black mastic." You probably have "cutback," a mineral based adhesive.

Black mastic.. is Asphaltic cutback adhesive.

They're are multiple different types. . The type used for gluing vynil and carpet is that which I said... also..... there is another type that is black and breaks down often. . Must be super careful with that particular type dude to its breaking down even if not sanded.. sorry for lack of punctuation. .. I'm actually working on a floor as we type.

How did your project using the Diamabrush turn out? I am desperately trying to find a contractor who uses one of those with no luck. I even called those guys at Phila. Floor Store (the guys in the video you referenced above) and they don't do the work--only sell equipment. I have pine floors covered in black mastic and hate the thought of installing tile over them just because no one in my part of the world seems to be able to remove the mastic. We are at a standstill with our kitchen remodel. Any leads to someone in greater Philadelphia/Delaware Valley would be appreciated. Thanks.

New here, I also am removing mastic from hardwood flooring. The tool that you're talking about is standard for refinishing concrete floors, at least with the company I worked for. I haven't ever heard of using it on wood floors. But, in regards to cyndiviolin, you might try to contact concrete specialists for that resurfacing, as they might have the tools or at least a better idea of the tools needed.

Hello everyone

I am working on my dad's house that was built in 1919 that have the black mastic on the floor. Home Depot did not have the 15 in Diamabrush for hardwood to rent only the one for concrete. I continue to search and I found that Diamabrush sells a smaller version that you put on an angle grinder. I am having to use the floor scraper hooked on to the compressor to get larger pieces of the old floor and mastic up and afterwards use the Diamabrush and grinder combo. I am using the Ryobi with the plug because it will give you 11,000 RPM. Recommendation for the Diamabrush is 8000 to 10000 but I called Diamabrush and a rep said 11000 was ok but just a lot of power. Please don't forget your respirator,goggles and a bunny suit since you really don't know what's in it.

And everyone has tested for asbestos before grind this into air borne particles (friable material)?

Very handsome...did the asbestos tests come back negative for the adhesive and the tile?

The hub and I finish the floor yesterday with the 4.5 Diamabrush and the angle grinder. We wore bunny suits,goggles, and mask. We had to leave for a furneal so when we go back next weekend I will sponge mop the floor to get up any sand dust that was left. I also used a wall paper steamer because we used a floor scraper hooked up to a compressor to soften and try and minimize the dust flying. We took precautions to make sure we had on PPE. Due to deadline I was not able to send to lab before starting but have save several pieces to send off so we will know. Once the floor has been sponge mop we will cover with a thin wood sheath before putting down a peel and stick floor.

@Ultimate Hardwood the 20 grit Diamabrush for concrete will work on the hardwood floor without tearing it up?

Your after picture is what mine looked like when I rented the drum sander. I am very happy with my wood floor.

@Frankreddy62 did you rent the one for concrete with the 20 grit?

I used the one for wood. I tried the concrete one but it didn't work. The one I used had maybe 8 abrasive blades on the bottom. Slow and steady

@frankready62 your floor is beautiful. Unfortunately, I want be able to do this to the kitchen floor. We had to cut out a trap door that you see in the pic above due to replacing the plumbing with PEX. The house is seating on Cedar Post and it is very low at the back of the house. I am going to put down a thin wood sheath before laying a new floor. I didn't want the mastic and old vinyl on the floor when I put down the new floor.

@Ultimate Hardwood LTD I was just wondering about your comment in an earlier post. "Diama brush is the way to go. Rent them at Home Depot. Wet the floor and giver! Works like a dream!! Make sure to rent the 20 grit concrete prep tool. We have performed this several times will excellent results."

The concrete Diamabrush will eat that wood up. Unfortunately the Home Depot didn't have the one for hardwood and to purchase it the cost will be 400.00 and that is why I got the angle grinder and the 4.5 Diamabrush for decks. It was very much labor intense but it got the job done.

Yeah I wasn't trying to buy it for 399.00 and I still would have had to rent the floor buffer machine from Home Depot. The 4.5 Diamabrush was 50 and the angle grinder was 40.00. The only thing that cost me was my time.

Where did you get it.. is like to buy one!!

Home Depot website

Diamabrush for Decks

I found a product that works on my black mastic on wood floors problem. Thank goodness. I found it at Home Depot. It is made by Klean Strip and it's called Flooring Adhesive Remover. It takes time to let it soak and you need a good razor scraper but it works! Sometimes you need a second coating for extra thick areas. Good luck. By the way it has almost no smell. That was a huge bonus!

Where do I get black mastic tested?

Ours was previously scraped off and now just looks like stain on the

I have an 1890's that someone had glued 1970's shag carpet to oak hardwood floors. Also had a maple hardwood floor in the kitchen with several layers of linoleum glued down with the black adhesive. After trying sanding, adhesive remover, paint stripper and scraping someone told me the solution that does work! It will sound counterintuitive but you mix a strong solution of TSP cleaner in a bucket of hot water. Then mop this solution onto the floor keeping it wet for 40 min or so. The TSP solution will turn the glue to mud which can be easily scraped off. When nothing else worked, this took care of the problem. If you leave the oak flooring wet too long, it can warp, but I used this method in 3 rooms and then was able to sand and finish and they turned out beautiful. The maple floor cleaned up beautifully as well! Attempting to sand the glue mess off the floor will fill up sandpaper sheets almost immediately - the TSP method works!!

Define “strong solution”. I believe the normal dilution is 2 tsp to a gallon of water