Is it necessary to get rid of paint on concrete before laying ceramic tiles? - DIY Chatroom

yummy mummy · 12-10-2008, 10:22 AM

My basement concrete floor is painted with what I assume is some type of concrete paint. It is shiney at parts, and some parts have worn out.

I eventually want to lay ceramic tiles and I don't want to use ditra, I simply want to lay them over the concrete. (The concrete has no cracks, no chance of moving as it is 70 years old.)

Do I really need to remove the paint in order for the adhesive to stick?

Thanks very much for any help.

Also, there is a certain part that I will have to use some type of self levelling compound. Would the compound work with the paint being there?

bbgunbob · 12-10-2008, 10:40 AM

Try a spot with the glue/mastic your going to use to set the tile .See if it eats the paint.If not get a 4" belt sander with 60 or down to 30 grit sanding belt.Rough it up and you should be good to go.
As for leveling I don't know a thing about that.

BBGun Bob
SE Mich.

yummy mummy · 12-10-2008, 01:45 PM

Can I sand and rough it up by hand? Would that work?

I just want to make certain that the adhesive will stick to it.
So that the tiles will not end up moving and cracking.

Thanks

bbgunbob · 12-10-2008, 01:52 PM

Yep you can that way a machine just saves time and labor.

Bob

Bud Cline · 12-10-2008, 06:37 PM

Quote:

Try a spot with the glue/mastic your going to use to set the tile .See if it eats the paint.

NONSENSE!!!

You don't use mastic with floor tile.
Thinset wont eat anything but your hands.

Where on earth is this notion coming from?

The Tile Council of North America publishes a "Handbook for Ceramic Tile Installation"

YOU can order one here: http://www/tileusa.com

Bud Cline · 12-10-2008, 06:39 PM

Yummy,

Painted concrete surfaces are a well known bondbreaker for all tile thinsets and self levelling compounds and must be removed prior to installing tile.

jamiedolan · 12-10-2008, 09:18 PM

Try a floor machine from a local rental place. You will want a very aggressive pad to remove paint. They are powerful and easy to operate once you get the hang of using one they work really well.
Jamie

yummy mummy · 12-10-2008, 11:26 PM

Quote:

Originally Posted by Bud Cline

Yummy,

Painted concrete surfaces are a well known bondbreaker for all tile thinsets and self levelling compounds and must be removed prior to installing tile.

Hi Bud

Would sanding it to the point where I remove all the shine be enough?
Or, (please don't say it,,,,,,,,,

) have to remove it completely to the bare cement? Oh no.........................

JazMan · 12-11-2008, 12:59 AM

Hi Bob, neighbor. Welcome to this forum, BUT that is what happens when you make recommendations that do not pass the "do-it-right" test.

Only hacks use mastic on floors. You could use it on back splashes in dry areas and that's about it. We do not recommend tiling over painted floors, it'll come loose one day.

Jaz

angus242 · 12-11-2008, 01:59 AM

Quote:

Originally Posted by yummy mummy

Do I really need to remove the paint in order for the adhesive to stick?

Also, there is a certain part that I will have to use some type of self levelling compound. Would the compound work with the paint being there?

Paint's gotta go

but Bud and Jaz have already confirmed that.

Note, before you use an SLC, you will most likely need to remove the paint AND use a special primer. I have only used Mapei Novoplan 2 and you have to use the primer over a properly prepared cement surface.

vsheetz · 12-11-2008, 02:35 AM

Quote:

Originally Posted by jamiedolan

Try a floor machine from a local rental place. You will want a very aggressive pad to remove paint. They are powerful and easy to operate once you get the hang of using one they work really well.
Jamie

I have also used a floor machice with a pad to remove paint from concrete and it works well. One time however I tried it on a concrete patio and was unsuccessful. I then used a pressure washer - it removed the stuborn paint super easy. Not knowing if your basement will allow for this - has a drain, etc. - but may be a consideration.

Vince

yummy mummy · 12-11-2008, 10:23 AM

Ok, I get it..........I have to remove the paint.

I don't want to do it with a machine because it will probably send me flying into the air.......

What can I use to remove it, by hand. I don't want to use any chemical products.

I think the paint is oil based. How would I know?

Thanks

yesitsconcrete · 12-11-2008, 10:39 AM

it doesn't take long to learn the scarifier OR a conc grinder's technique.

we typically use hand grinders fitted w/dust shrouds hook'd up to wet/dry vacs running turbo-style diamond cup wheels either 12 or 24 segs,,, your apron store might rent these,,, usually any paint hasn't penetrated that far into the conc to interfere w/a new surface however occasionally you may need to install a polymer-modified overlay if nec.

angus242 · 12-11-2008, 11:20 AM

Quote:

Originally Posted by yummy mummy

Ok, I get it..........I have to remove the paint.

I don't want to do it with a machine because it will probably send me flying into the air.......

What can I use to remove it, by hand. I don't want to use any chemical products.

I think the paint is oil based. How would I know?

Thanks

Oh you are a glutton for punishment....by hand? That's too much work.

If you could rent a setup like this, it would be very manageable:

I own this combo and it will beat the heck out of doing it by hand (and no, that's not me in the pic). Notice the vacuum? It automatically turns on when the grinder is switched on. Catches about 90-95% of any dust that it created by the grinding.
Finding something like this will save you hours over doing it by hand.
Say it with me...."I can do this. I can do this...."

As for the paint, maybe someone can verify this but rumor has it, rubbing alcohol will remove latex paint but not oil.

yesitsconcrete · 12-11-2008, 12:00 PM

angus, is that the bosch 4" conc planer ? ? ? we use std 7"/9" 15a grinders,,, MUCH faster & MUCH less expensive ! ! ! beaneedoo works but it leaves its own stains/mess.