tar

[1930]

Ripping out my bathrooms floors and to my delight the tile that has been there longer than the 7 years I have lived in this house just lifted off practically with my fingers. Surprised me because I have never felt a loose or shifting tile.
It did not stick because there is some sort of black very thin tar like coating under it, very thin but just thick enough so that the cement cant be seen. I have seen this same stuff in one of my closets I tiled and thought better than lay down tile on top of it so I tried cleaning it off with kerosine/mineral spirits and elbow grease. It turned into what looked like tar to me.
Does anyone have any idea what this stuff really is and why it was put down on the floor?
I would like to remove it all before tiling the bathroom and would like to know the most efficient manner.

[Fins/413]

I'd guess its some kind of adhesive. I'd try gentle heat or maybe other solvents maybe some Isoprpyl Alcohol.JUST NOT AT THE SAME TIME. You also might ask someone at your hardware store or  home center. One thing that came to mind is a product called "Goof Off" Good luck

[rusty]

It is an asphalt adhesive. it was popular for gluing down asbestos tiles, beware.
It is not uncommon for it to stick like mad to concrete, and not very much to the tile , probably why they don't yuse it any more.

You may be able to use an isolation primer over it, instead of removing it, need to talk to a tile guy who does restoration work, I know they were trying that approach at one point, but I don't know how it worked out.
 
I don't know of any nice clean way to get it off, it is awfull stuff, goof off will just make it thinner and it will smear all over the place. Grinding it off may be a very bad thing to do if it had asbestos binders in it. The few ways I know of to get rid of it require professional chemicals or tools : (

(Paint remover will, very slowly, decompose it, but it's a nasty way to do it )

[64longstep/Brian]

You might give Trewax Natural Orange Heavy Duty Cleaner/Degreaser a try, you can pick it up at Home Depot…

[1930]

Thanks for all the tips, Rusty, the home was built in 71, would they have used that sort of thing then? I though we were over all of that by then.
Ill hit it with muratic acid maybe and see what happens worse case scenario if the other attempts fail.

[rusty]

71 is right on the edge for floor tile, probably not asbestos...
Muriatic acid will make some nasty fumes reacting with that, be sure you open the windows...

[scottg]

Not the acid!!
 The fumes will destroy (corrode) every piece of metal in the room!
 Kiss your faucets and valves and medicine cabinet goodbye, at least the finish.
 
  I would try to chip it.
 Get a floor chisel and ice. Keep it cold and dig in. I have done it, but I was young, and its a miserable job.
 They sell pneumatic floor chisels, maybe you can rent one?
 yours Scott
 
 
 

[Aunt Phil]

It's an asphalt base mastic that employed a low flash point solvent as a thinner originally.  Your nonsticking tile are a sign the floorlayer put too much mastic down and didn't get tie tile in place before the solvent flashed off. 

The removal is going to be a trip to funland since the material well adhered to the underlayment.  It well might be easier to remove and replace the underlayment which would generally have been 1/4 plywood with all seams "plastered" with a fast setting joint compound.  If you don't have underlayment and have mastic directly applied to concrete, NO SOLVENT will work.

If the area is large, get a machine called a scabber from a rental place.  The wheel looks like a disk with multiple rows of grinding wheel dressers.  It will take you to bare smooth concrete.  Hot 200°+ pressure washing will also be very effective, but you probably don't want that inside a house.  Another S L O W method good for small areas is paper towling applied direct to the mastic with brown wrapping paper over it and a couple garage sale irons. 

Worst case, check the website for Henry adhesives.  They make some really sticky goo and may have a product that will adhere to the old mastic.

[1930]

It was not originally used to lay common floor tile down, it has the thickness of a rattle can paint, you cannot feel anything but concrete when the hand is run over it, they only used it in this house  on the concrete within the closet areas and now I have found it in this one small bathroom.
Again it is thin like paint and just barely covers the floor so that the concrete cannot be seen in most places.
There was the thin vinyl tile in many areas throughout the house still, paper/heavy carboard thin vinyl tile.
I am not worried about corrosion from Muratic acid, there are no appliances, the walls are stripped down to the studs and not alot of copper pipe left.

[Aunt Phil]

I'm not concerned with muriatic in your house either, but I got a whole US Dollar says the acid don't touch the stuff.

You might want to try lye gravy or even EZ Off.  There is a better chance it will eat the mastic.