What is this orange stuff?

Question

I am removing 4x4 tile from a 1957 concrete block house kitchen backsplash and I expected to find thinset under the tile, but I found this orange stuff instead. What is this stuff and can I tile over it without any special prep?

Linda · Answer

I plan on replacing the 4x4 tiles with 12x12 mosaic sheets.

Burco Surface & Decor LLC. · Answer

glue, it would be in your best interest to get it off before going over it with anything.

KMS Woodworks · Answer

Mastic would be a more appropriate name as it was used to set the tile.  It looks like from your pic that when you tried to remove some of it it peeled the paper off that part of the dry wall.  Ideally setting the new tile on some fresh drywall would be best.  But I have know of many instances where a Skim coat of new mastic was used to set over this old stuff.

Linda · Answer

How would I remove it? Sanding?? It will not wash off and has probably been there for at least 50 years.

KMS Woodworks · Answer

Sanding could help even it up ( at least to take out the higher bumps) but it would not be practical to try to sand it all away.  I would try to knock down the highs and loose bits then skim it with some 'setting' type drywall mud.  Then after that is full set  a light sanding of that then set the new tile with some Arcylpro mastic.

Linda · Answer

This is a 1950's concrete block house- there is no drywall. It is concrete block with a skim coat of concrete to hide the block lines. Here is a photo of the corner where the most  concrete came off with the tile. I am removing each tile with a chisel. I am trying to do as little damage as possible. Some spots the tile is glued on better.

Melanie L · Answer

put dry wall up over it ... and then do u r kitchen over...

Becky H · Answer

Wow!  No dry wall over concrete block?  I've never seen anything like that.  Our block house was built in the late 60's and our perimeter walls have firring strips w/dry wall attached to them.  During our kitchen remodel, we had the same mastic, and it was easier to rip the dry wall off and replace it than to try to smooth the old surface.  Smoothing is quite labor intensive.

Nichter's Home Services Corp · Answer

Normally mastic can be softened to scrape off by using heat. You could try the hair dryer or a heat gun on it, but after fifty years, it is probably too far gone and brittle such that a cold chisel will be the better removal tool. Whether to patch anything then depends on how bad the surface is. You could go right over it with the new thinset if you are good with a towel, but probably best to smooth it first

Dawn K · Answer

if you are indeed on concrete, there is no place for mastic or glue behind tile.  You really need to go with a crete/mortar based adhesive for your tile.  Talk with you local do-it-yourself store and see what advice they have for you.

Thom S · Answer

I've seen that type of building before. It's basically a wing wall inside of the home. Need to be careful when using the chisel, don't want to create big gouges in the block. U can use a sander, suggest you curtain off the room, will be quite messy. Since the glue is directly on the block, all you should need to do is knock down any high spots and what ever is loose.

Carol B · Answer

The mosiac sheets would be beautiful!!  I would knock off the concrete and glue and put a new surface up to tile.  Not sure which way I would go for the new surface. Would tile be secure on drywall or would it pull the paper layer off over time?

Mark, M · Answer

Screw cement boards to the concrete. Tile. Do not sand. Some old mastics had asbestos.

Carol H · Answer

Most likely like that pink gunk I've seen in some people's showers and tubs from not cleaning, some sort of mold

Pensacola Accents · Answer

Mark's suggestion is the way I would go...the LAST thing you need to do is release asbestos into the air.  Cement boards would give you the even surface you will need for your job.

KMS Woodworks · Answer

Linda...smooth it out as best you can then tile over the top..adding any additional 'layers' via drywall or cement board will give you too much thickness to do a proper edge detail

Rebecca W · Answer

It's the glue they always used to use. Very hard to get off, but will be better if you do. Use a sander to get it off

Rebecca W · Answer

Better yet get someone who knows how to get it out of your house.

Lynda B · Answer

Linda, are you going to remove and replace the counters and small back splash?  If so you can start fresh and not worry about adding any thickness to the new back splash with the hardy backer board for tile installation.This will give you a true and level surface for your mosaic tiles. You will use a tile with a radius edge to finish the edge detail

Lynette O · Answer

It is mastic and as another said be careful for asbestos was used in about everything prior to the 70's,  adhesives you name it was in it... so NO SANDING! I would use cement board over the cement blocks and use cement/concrete anchor screws please wear a mask when drilling  then apply the cement boards with screws to avoid dust. If you don't want tiles  then use green sheet rock board using the same method but tape seams and mud in screw heads and seams.

Charles Q · Answer

Linda, if you want to remove the mastic it would be good to buy a face mask , scrapper with a 4 inch blade (might need a few blades). Then wet down the mastic to keep dust down and slowly scrap the old mastic off the cement walls. You might end up taking the top coating with you as you scrap, but that's okay. You can also score around the outside edge with a utility blade to make sure nothing outside the area comes off by mistake.

Nancy S · Answer

I had that in my kitchen when we pulled off the old, very high, formica back splash.  It was very difficult to remove so I went with plan B which was to use Venetian Plaster over it instead of tile.

Linda · Answer

Thanks for all the replies. I am replacing the countertops also, so the area behind the sink can be replaced with drywall or backer board. The area above the stove and next to the sink ( small 24 inch by 18 inch)  would be difficult becuase the drywall/backer board would not be flush with the concrete walls. I was kind of hoping to try out that new Bondera Tile installation system, but there were too many surprises behind the tile.

Tiffany J · Answer

its old glue that held up the tile.Be careful most tiles from the 50s have asbestos and you need a protective mask. Not just any mask, but the kind that is used to remove asbestos tiles.

ClarenceWaggoner Remodeling & Repairs · Answer

I do a lot of remodeling and come across this often. I would knock down as many high spots as possiable and skim coat with 45 or 90 min drywall compound and light sand. Also you can pull the top layer of paper off with the glue and skim coat with 45 or 90 min. mud. If you use 20 min mud in concrete areas it will become hard as a rock, but only mix as much as you can use in about 10-15 min. as it will get hard very fast and is a little hardder to sand. Also if you are using the 20 min. mud on the paster or concrete areas, wet damppen the area first and then apply.

Gabrial G · Answer

Do not sand it! Use a heat gun and it will scrape off with ease.

Diane T · Answer

old glue,

HandyANDY - Handyman & All Repairs, LLC · Answer

It's important to remember that you're getting advise from all over the country...but the right answer in PA for instance maybe the wrong one for FL.  Adding any kind of drywall here will create a place for mold to take root as the paper will act as a vapor barrier on what is likely an uninsulated home.

You're best answer is to leave it alone if it is still well bonded and skim over it with 20 min mud or thinset to achieve the desired thickness taking the new countertops into consideration.  Go ahead and get set for the countertops first....skim the walls out some for now but come back and finish once you have the countertops in.  Do you have electrical in this wall?  If not, you may wish to plan for conduit & incorporate that into the wall design.

Linda · Answer

I am doing a mosaic tile with a butcher block (laminate) counter top. I have been planning this re-do for so long, the counter tops went from stock to special order.

Susan B · Answer

it looks exactly like the stuff they use to put up a shower plastic wall with.It is water proof and once you put it on the back of the shower wall it will set up so fast.not sure what to get it off with, but the best thing is to take that part of the wall out.

What is this orange stuff?

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What is this orange stuff?

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