Help: Removign cutback adhesive - prepping existing concrete slab

[hudsoncustom]

Greetings fellas.

I'm hoping for some guidance with a situation I've got to get resolved.

Recently, we had some really nasty wind and rain here in WA, and we had water leak into our family room through a crack in a foundation wall. I did not know we had a crack previously, but the crack has since been repaired and is no longer leaking.

The water saturated the carpet on the floor, so I removed the carpet. Under the carpet were 9x9 VCT tiles. They have all been removed as well.

The adhesive residue used to install the tiles is giving me problems. This stuff is black, smells like tar/asphalt, and is very hard. I did a little "crack internet research" to try and get a handle on how to remove the stuff, but nothing I am trying is working.

I used a bit of a solvent based adhesive remover in a test spot - it turned the adhesive into a goo, and smeared it around really good, and worked it into the pores of the test square.

I tried soaking the slab in warm water, and then used a 4" bladed scraper to try and get the old adhesive up. I had moderate success with that, but holy **** is that a slow process! It is taking me about 20 minutes to scrape one 9"x9" area!

I obtained a sample of a product called Sentinel 747, and tried another test square tonight, but again, the results weren't great. I let it soak for about 30 min (the tech sheet said to let it sit 10-20 min). It removed some of the adhesive, but no more than scraping with just the warm water, and made a big mess too.

I'm about at my wits end with this stuff. I'm thinking of renting a diamond grinder and going to town. I know this cutback stuff *may* contain asbesots, but I figure if I seal the room well, and wear a full respirator suit while grinding, and then soak the slab and wet vac after the grind, the asbestos would be a non-issue.

The ultimate goal is to have a clean slab that I can stain and seal, or put an epoxy coating down on. The floor measures 20x12.

Have you guys run across this stuff? If so, what have you done to remove it? Anybody tried diamond grinding or shot blasting to get rid of this?

Thanks for the help...

Keith

 

[dcs Inc]

I've had to remove this stuff many times. It's no picnic but doable. Ive used shot blast machines, (if brittle) and large grinders. I've not used any chemical removals.

On grinding, I use scrapers first to take the majority of the stuff off and then grind with 16 or 30 grit diamonds. I've heard That dry ice will really help it come off. The tile scrapers that rental companies rent with the mastic blade cutters really helps. You still need to grind it to remove the **** in the pores of the concrete.

If you are wanting a nicely finished surface to stain, this becomes an issue when grinding. You can't go Willy nilly with an aggressive grinder because of damaging the surface. 40 grit diamonds will keep the swirl pattern to a minimum.

I'm usually applying an overlay over the concrete then coloring and epoxy so I can get pretty aggressive with removal. Good luck, gene ec-Indy

 

[TommyK]

Please be careful using mechanical removal methods. Many of these older adhesive and tile products contained asbestos.

 

[dcs Inc]

Good point TommyK. There have been times when I wasn't sure and went ahead and encapsulated with epoxy. Normally I'll use our PT4 colored epoxy and then apply a coat of PT1 clear with Reflector Enhancer metallics. gene ec-Indy

 

[djjsr]

Just a thought - I cleaned some tar off of brick last winter. Outside temperature was below freezing, the tar was brittle and chipped off pretty easily. Maybe you could try freezing a small area. If it helps, then big blocks of ice might do it?

 

[slickgt1]

try paint thinner. If it is mostly tar, paint thinner will soften it up very well. Then use a scraper. Let the paint thinner soak in. Make sure you have good ventilation and wear a mask. You might pass out from the fumes.

 

[cderalow]

side note, removal of asbestos by an unlicensed professional is a federal offense.

 

[jhelrey]

Tommy- He was already aware of this!

 

[slickgt1]

side note, removal of asbestos by an unlicensed professional is a federal offense.

Yea don't tell anyone.

 

[dcs Inc]

Reread your post. The 9x9 tiles would have thrown up a flag. So you may have already been into the asbestos ****. gene ec-Indy

 

[tncatadjuster]

Any 9"x9" tile is going to be old enough for asbestos to be involved.
Shotblasting will remove all cut back and provide a good surface.


Paint thinner? Really?

 

[slickgt1]

Paint thinner works on tar, that's what I was going for. Don't know if it would work or not here.

 

[TommyK]

Tommy- He was already aware of this!

Yes, clearly I missed that acknowledgement in the original post. When I saw what the OP was trying to accomplish I just felt compelled to provide the warning. When I was young and starting out in construction and the boss said go rip that white insulation of the heating pipes I did it without question because I didn't know any better. Just wanted to give someone else the warning I never got.

 

[cderalow]

please do yourself, and others a favor, either encase the old adhesive in an epoxy, or call a professional abatement company to remove this stuff.

 

[pauls340]

I personally have never been in your shoes but if I were to see that black tar "****", i would find a distributor for a product called C-Tar Melt by EaCo Chem....that takes off just about anything black

 

[theoldwizard1]

I just did this with my son at his house a year ago. It was a bank repossession and standing water caused a lot of the tile to come off exposing the "cut back" adhesive.

We tried several solvents with no luck until stumbling upon Sentinel 747 Plus Adhesive Remover

Apply in about a 3x3 area and let sit for about 30 minutes. Use a scraper on the thick spots/blobs. Wipe off (I used LOTS of blue paper shop towels). It probably will require 2 treatments and even a third on really bad spots.

The floor will not look "clean", but I did epoxy coat it (laundry room) and it is holding up well.

 

[slickgt1]

I personally would have tiled right over it.

 

[Edger]

try paint thinner. If it is mostly tar, paint thinner will soften it up very well. Then use a scraper. Let the paint thinner soak in. Make sure you have good ventilation and wear a mask. You might pass out from the fumes.

Do not light a match, turn off gas heaters.