Tile prep...how much?

[luvmyglockfou]

Here's the story:
I bought this house, built in 2001, last year. The concrete in the garage is terrible. There are places where it is chipping up, and a couple small cracks. There is even a quarter-sized hole that somehow got in the floor. The actual concrete seems fairly solid; I can hit it with a 4lb sledge and it doesn't break or anything. The previous owner attempted (can I even use that term) to paint the floor with some sort of grey paint. He failed miserably. As you can see in the pics, he didn't even attempt to get a straight line painted at the edge where the overhead door comes down. It's downright hideous.

All that being said, I have decided that tile may be my best option. I like how it looks, it'll take some abuse, and it's cost effective if I get some PEI4 or 5 on clearance. What do I have to do to get this floor ready to lay the tile? How much prep work is absolutely necessary? Do I have to remove the paint first? Working this out on an E-4 budget isn't the easiest, so please let's speak in terms of cost-effectiveness! That being said, I don't want to put down inferior tile that I will have to rip up to fix it. So take a look at the pics and let me know what is the best course of action here. Thanks for the help guys!

The AWESOME paint job....

An overall shot of the whole floor:

 

[JimVonBaden]

Looks like a great start to a garage.

A good base to attach the tile is critical, as you suggested. I would imagine getting the paint up would be good enough to put down the tile. Those with more knowledge than me will chime in, but other than the **** paint, it doesn't look like you will have much prep to tile it safely.

Jim

 

[luvmyglockfou]

Thanks Jim! By "get the paint up" do you mean grinding the whole floor, or is there an alternative? I'm a tile newbie!

 

[JimVonBaden]

You could grind it, but that is pretty hard and messy. You could also sand blast it, also messy, or use a pressure washer, could be problematic with drywall.

Me, I would use a scraper and wire brush. Hard work, but cheap, and you do not need every bit of paint up, just that which is loose, or come up with a scraper.

Jim

PS I am sure some will disagree, but that is my take on it.

 

[luvmyglockfou]

I tried a pressure washer...the paint doesn't come up..whatever he used its really on there...there really isn't any loose paint or flaking paint to remove. My problem here isn't bad paint, but a chipped up floor...well hell the pics tell that story..

 

[JimVonBaden]

If the chips are not more than 1/4" deep, the thinset will cover it, so long as they are small. Big chips will require filler first.

Jim

 

[luvmyglockfou]

As you can see, most of them are quite superficial. No big deal. I do have to fill the crack in the concrete, even though it is very small. It makes me feel better. Ive got some concrete crack filler stuff that the wife got forever ago that I think I can use for that. I'd like to head some more opinions on whether or not I need to remove this paint, however. Any experienced tile guys around here?...

More pics with quarter for reference. This is the worst of it folks!

Chipping the thickness of a quarter. This is the deepest it gets throughout the garage.

The only crack I have...hardly a crack but does it need to be addressed?

 

[luvmyglockfou]

Nobody else???

 

[JimVonBaden]

Sorry, I gave all I have. It looks, to me, like you can use the Mastic to fill the shallow indentions when laying the tile. I am not a professional.

Honestly, I am surprised some of the professionals who sponsor the site haven't chimed in. Maybe they do not see any profit in it?

Jim

 

[luvmyglockfou]

I share your sentiment Jim. I'm just surprised that I haven't gotten more feedback. YOu post on here about epoxy and you'll be busy for days reading responses. Talk about tile prep and you get crickets...Is it possible that nobody really knows the true answer here? I even added more pics....Weird. Thanks for your help though. I have taken it into advisory.

 

[zxttfan]

If the paint won't come up with a pressure washer, your best bet is paint stripper. Since it's a garage with plenty of fresh air, buy a standard stripper, not one of the environmentally friendly ones. They don't work as well.

Use HD gloves, long sleeves and a good mask and buy a long handled scraper. It will probably take several applications to remove it, so figure on a weekend's worth of work. Let the residue dry out after scrapping and dispose of properly.

You'll probably have to use Citrus stripper/cleaner to get the last of the paint off the floor, then power wash it to get of any remaining residue and wash down the surface. Let it dry and you'll be ready for tile.

As for the minor imperfections in the concrete, just add a little extra thinset to level it before you tile over it. I would also use mesh tape to span any cracks in the concrete floor.

All this stuff can be purchased at any hardware store or big box. Jasco is the stripper I use for well ventilated areas.

 

[luvmyglockfou]

Thanks for the info. The texture of the floor may make it very difficult to make scraping effective at all. It simply isn't smooth. I can certainly give it a try though. I'm mainly wondering if I needed to remove the paint, and if I did need to remove it if it was safe to use stripping chemicals on the concrete.

 

[zxttfan]

Thanks for the info. The texture of the floor may make it very difficult to make scraping effective at all. It simply isn't smooth. I can certainly give it a try though. I'm mainly wondering if I needed to remove the paint, and if I did need to remove it if it was safe to use stripping chemicals on the concrete.

The stripper will do most of the work for you. I would use the scaper for the first couple of passes. Really rough areas will probably require a stiff brush. Also, the scraper will create additional chips in your concrete. Just fill those with thin set when you tile.

You won't get everything removed, but the more you get off the floor the better the thin set and tile will hold. You could also use diluted muriatic acid to clean the floor as the final step, but you might not need it depending on how the floor cleans up.

 

[vansgarage]

I f u cant get the old paint up with a strong pressure washer that means it is bonding well and should not be a problem when tiling. I sugest using a good thinset mortar that is modified and if it has cracks using a thinset that has a crack isolation characteristic in it Custom brand. If you have moisture coming up in winter you may need some kind of membrane so you wont get efflorescence in your grout. One more thing use a porcelain tile that is thru body in case you chip it from dropping something heavy it wont show up so bad.
Good Luck Tile Contractor Van

 

[zoras]

I would strongly recommend removing the paint before tiling. I have no idea what type of paint the guy used, but most paints does not bond to concrete very well, and when tile is installed over the paint, usually the paint will release from the slab or the thinset won't bond well with the paint. A painful lesson I learned many years ago.

I'd suggest renting a hardwood floor sander from home depot or other tool rental place in your area and using either a very coarse sandpaper or a hexpin with the grinding attachments, which may be hard to find. Either would work fine, it will just take some time.

 

[zxttfan]

I f u cant get the old paint up with a strong pressure washer that means it is bonding well and should not be a problem when tiling. I sugest using a good thinset mortar that is modified and if it has cracks using a thinset that has a crack isolation characteristic in it Custom brand. If you have moisture coming up in winter you may need some kind of membrane so you wont get efflorescence in your grout. One more thing use a porcelain tile that is thru body in case you chip it from dropping something heavy it wont show up so bad.
Good Luck Tile Contractor Van

Based on the pics, I think the paint is showing signs of minor flaking in areas. If you tile over it and you have a moisture problem -now or in the future- you will have a bonding problem. Everything is exposed now- it's much easier and cheaper to remove the paint now than risk doing it again in the future.

 

[zxttfan]

I would strongly recommend removing the paint before tiling.

I'd suggest renting a hardwood floor sander from home depot or other tool rental place in your area and using either a very coarse sandpaper or a hexpin with the grinding attachments, which may be hard to find. Either would work fine, it will just take some time.

The main issue with using a sander/grinder is the dust. Everything will have to moved out of the garage or you will spend as much time with a shop vac cleaning as you will with the grinder. Wrapping large items in plastic will help but it's not dustproof. Ask me how I know..

Using a floor stripper is also messy but only requires moving items off the floor. Anything attached to the wall can stay. For me it's the better option in this case.

 

[Dakota00]

To do a proper job, remove the paint before tiling. Sand it or strip it what ever works for you, just get the paint off.

 

[rlitman]

I would listen to the advice to use mesh tape over the cracks, and the crack isolation thinset, just because I would be afraid of the cracks telescoping through the tile.

I would also probably go over the spalled areas with a self leveling compound so I didn't have to worry about the thinset making up the difference in thickness. It's really a very minor step in the whole process.

 

[coolreed]

I agree with using a real good honkin pressure washer. That should clean up the paint issue. Once the floor is clean I would use some leveling cement. When I built my last home the Tile Layer mixed up some leveling cement and just poured it onto the floor (a new slab floor) and the mixture filled any voids and it actually leveld itself. It was amazing and simple. He let it cure and then started laying tile.

 

[MoonRise]

I tried a pressure washer...the paint doesn't come up..whatever he used its really on there...there really isn't any loose paint or flaking paint to remove. My problem here isn't bad paint, but a chipped up floor...well hell the pics tell that story..

Not a little-bitty pressure washer.

A 'real' pressure washer. Around 3000+ psi or so. If you have the 0 deg tip in and/or get too close to the concrete, you can etch or score the concrete itself.

Any paint on top of the concrete would not stand a chance.

Any impending 'loose' concrete will be removed. Rapidly and with possible velocity behind it (watch out for the flying debris!)

Messy and wet, but usually faster than grinding the entire floor down (as well as a bit easier on the back!)

Once the floor is dried out, apply the 'appropriate' concrete leveling/patching compound(s).

Then you can get to the thinset mortar and tile stage. And after that the grout stage.

To really isolate the tiles from any possible movement of the slab underneath, use an isolation membrane as mentioned. A big name for that is "Ditra" by Schluter.

http://www.schluter.com/6_1_ditra.aspx

An explanation of isolation membranes:

http://www.schluter.com/3769.aspx

 

[rlitman]

Ditra is great stuff for indoors. Do you really think it is a good idea for tile over a slab? Especially one that can get heavy loads on it.

 

[luvmyglockfou]

Not a little-bitty pressure washer.

A 'real' pressure washer. Around 3000+ psi or so. If you have the 0 deg tip in and/or get too close to the concrete, you can etch or score the concrete itself.

Any paint on top of the concrete would not stand a chance.

Any impending 'loose' concrete will be removed. Rapidly and with possible velocity behind it (watch out for the flying debris!)

Messy and wet, but usually faster than grinding the entire floor down (as well as a bit easier on the back!)

Once the floor is dried out, apply the 'appropriate' concrete leveling/patching compound(s).

Then you can get to the thinset mortar and tile stage. And after that the grout stage.

To really isolate the tiles from any possible movement of the slab underneath, use an isolation membrane as mentioned. A big name for that is "Ditra" by Schluter.

http://www.schluter.com/6_1_ditra.aspx

An explanation of isolation membranes:

http://www.schluter.com/3769.aspx

Thanks for the info. I have a craftsman 2500 psi pressure washer. With the turbo tip on it it will remove the paint..and about 1/8 inch of concrete! That's the problem...I have tried a wire brush, a pressure washer, all sorts of stuff...nothing takes the paint off without taking the concrete with it. I figured a wire brush would, but I tried that last night after reading the replies and it just took off concrete....Frustrating!

EDIT! Okay, so I just went out and dumped about a cup of reducer (for auto paints) on the ground, and then went at it with a wire brush. No concrete came with the paint this time.

I think that whoever said to use a stripper had it right on. Stripper and a deck brush, and then a pressure washer at the end. Only issue is the $30/GAL for the stripper at lowes! How many gallons am I going to need for a 20x20 garage? Too many..

ALSO, what's up with the aggregate in the finish? I can see it ALL over the garage under the paint..

 

[TRC51]

Off topic for a second..... those look like Cocept One RS8's.

 

[slickgt1]

Well, I am going to get some heat for this. But, if the paint doesn't come up with scraping, I would rough it up, as fast as I could, and tile over that. That surface is very rough as it. Thinset with some Kerabond additive will make the tiles stick like no other.

I said this before, but I keep forgetting to take pics. I tiled right over 1YO commercial grade epoxy paint (bus depot floor type epoxy). The tiles are outside, awning over them now. Tiles are still in place, and nothing came up 1 year so far. Now that deck was super smooth, that's the reason it got tiled, way too slippery. I was concerned the tile would not stick. After a 4 day cured test sample required a chisel and a sledge to remove the tile, I didn't think about it any more. I say, get a tile. Mix a little thinset, set that. Then set another with Kerabond. Wait a couple of days and remove it. See what comes up.

 

[MoonRise]

Ditra is great stuff for indoors. Do you really think it is a good idea for tile over a slab? Especially one that can get heavy loads on it.

Yes.

See the last paragraph in the Ditra write-up.

http://www.schluter.com/6_1_ditra.aspx

I'll quote:

Loads are transferred from the tile covering through these column-like mortar structures to the substrate. Since DITRA is virtually incompressible within the tile assembly, the advantages of uncoupling are achieved without sacrificing point load distribution capabilities. The ability of DITRA installations to support and distribute heavy loads while preserving the integrity of the tiled surface has been verified through extensive laboratory and field testing, including applications exposed to vehicular traffic.

To the OP,

If a wire brush takes off the top layer of concrete, I suspect that the slab was not 'installed' very well. Same with the pressure washer taking of 1/8 inch of concrete (you do have to back-off with the pressusre washer and find the right tip/distance that you remove what you want to remove and mostly leave the underlying material).

With the aggregate that close to the surface of the concrete, I think the slab was done poorly and not tamped down (to 'push' the stone coarse aggregate down a bit) and/or worked while too wet (or they had too much water in the concrete mix to begin with) and thus had too much "cream" on the top. Maybe the previous owner(s) got tired of that weak top-layer of concrete turning to dust and they pressure washed it off and then glopped that paint on there to try and make it look a little better.

At this point (over the internet, from your description and a few pictures), I'd really tend towards using the pressure washer to remove the paint and the weak top layer of concrete. Then apply the Ditra (or similar) with a good acrylic-modified thinset (extra stick from the acrylic additive) and then the same acrylic-modified thinset on top of the Ditra and then your good PEI5 tile. I'd rather spend a few extra bucks on the 'premium' thinset and be assured that the floor is attached well than to try and save a few bucks and have tiles be 'loose'.

+1 on going for a porcelain tile (color goes all the way through) and not a glazed ceramic tile (color is only in the glaze coat on top).

IMHO.

 

[rlitman]

Yes.

See the last paragraph in the Ditra write-up.

http://www.schluter.com/6_1_ditra.aspx

Neat. I hadn't considered the fact that the mortar will fill up the squares to support the compressive load.

 

[slickgt1]

If your slab is moving and shifting around, I say maybe consider Dirta. If you go with the Dirta route, the price of your floor will double. Dirta is something around $1+ per foot. I personally would not use it. You are putting tile on concrete. Once the tile sets, it is not exactly going to jump off, or decide to move past the other tiles.

Everyone seems to forget the beauty of tile floors. Even if something shifts and 10 tiles break. So what. Break another 20 tiles around the fracture, address the fracture, and tile again. It will still be cheaper than applying Dirta. That's what, $30 and some thinset? The chance of your tile delaminating from rough-aiss concrete are slim to none. Don't over think this. Do what I suggest. Stick two to your floor, and see how much effort it will take to remove. Trust me.

My garage floor was actually moving around if you walk in certain spots. I also had a painted floor. Click my reno link. See if you see anything there, where I power washed, or degreased, or Dirta-d, the floor. I peeled the loose paint up. I vacuumed the floor, I hosed it once.

Trust me, had I not poured columns to stabilize my moving section, no amount of Dirta would decouple it from the tile. Especially when rolling a 5000lb SUV over it.

Yea people are giving solid advice for a solid floor. But have you seen anyone on here posting about their tiles popping off or moving around? NOPE. Have you seen anyone using Dirta? NOPE.

 

[luvmyglockfou]

Wonderful points here. Ill agree; I haven't seen threads with tiles coming off. I think the cheapest and easiest way will work just fine. Interesting opinions here though.

 

[Dakota00]

Slickgt, said it pretty bang on. I'll keep it simple and sweet. Prep the surface well, use the proper thin-set for the application. Make sure the tiles are applied with no voids in the thin-set, you'll be golden!! There will be no breakage or cracking in the tiles as the slab has already cracked and settled.
There's absolute no need for Ditra!!

 

[luvmyglockfou]

Thanks Dakota. There's a TON of knowledge here, and I have never done tile before. I depend on you all to make sure I can at least pretend like I know what I am doing Thanks for the knowledge. I couldn't do it without ya....now to go tile shopping!

 

[Randyman]

Thanks for the info. The texture of the floor may make it very difficult to make scraping effective at all. It simply isn't smooth. I can certainly give it a try though. I'm mainly wondering if I needed to remove the paint, and if I did need to remove it if it was safe to use stripping chemicals on the concrete.

Paint stripper, putty knife, wire brush and the pressure washer worked real good in my garage. Put the stripper on with a big paintbrush and let it work.