Working with epoxy tile adhesive (tiling over expoy finished concrete)

[R-mm]

I am tiling over a previously epoxy'd concrete slab. I called Laticrete and they recommended their 300 Epoxy adhesive. I do not have much experience tiling so I am posting to ask what your experience is with adhesives like this. I am aware it will have a shorter pot life than regular adhesive (45min compared to a few hours according to Laticrete). I realize it will be more expensive as well. Any other downsides or alternate methods to consider for installing over expody'd conc?

LATAPOXY® 300 Adhesive

LATAPOXY® 300 Adhesive is an epoxy with a high bond strength that will bond with most surfaces. Find a distributor & get it today!

laticrete.com

 

[duneslider]

Epoxy mortar is not fun to work with in my opinion. It will stick well. I do not believe "I don't have much experience tiling" and "should I use epoxy mortar" belong together.

I would be shocked if Laticrete 254 Platinum didn't work, it will stick baby oil to baby oil. (sarcasm for sticks really good). I used it to stick tile to stainless steel and it ain't coming off. Sticks to glass like nobodies business, any only comes off your skin with sand paper. I honestly would say the 254 will stick to the epoxy better than the epoxy is stuck to the concrete.

Best option would be to remove epoxy before tiling...

 

[R-mm]

I appreciate that feedback. I am a do it right kind of guy (see my 10 year Alfa restoration...) but I do not think I can bring myself to grind the epoxy off. I rented a grinder when I moved into this space and thinking of that dust in my shop now full of machine tools, welders and so on... can't do it. So I need to settle for good-enough.

I read Laticrete's selection guide and I see 254 rated for vehicular travel and has an extended work time. That does sound tempting. I suppose I can test an area under the sink and see.

 

[R-mm]

I'm readning possibly too much about trowel size selection. I believe for my 4"x8" tile a 1/4in x 1/4in square trowel will do. Does this sound like a good starting point? I understand that much of it is technique.

 

[Kobuck]

I doubt 1/4 x 1/4” will do. With the lugs on the back you will likely bottom out on the slab. When you “set” tile you don’t want that. But as you said, starting point. Try it.

 

[R-mm]

Thanks. Can you help me understand the lugs and how they effect technique / coverage, trowel selection?

 

[red]

I would start with a 3/8" towel, but you might need a 1/2". When spreading the thinset grind it into the floors, pros call that burning it in.

If you decide to go with epoxy mix only half batches and fill a 5gal bucket up with a couple of inches of water with ice in it. Then place your mixed bucket (like 2gal container) inside the cold water. Epoxy is heat sensitive. The colder the epoxy is the longer it will take to cure which will increase your pot life. There's lots of videos on you-tube on tile installation.

 

[duneslider]

With tile that small I would be shocked if you need more than a 1/4 x 1/4 trowel. I would key the mortar into the floor, then trowel it, then key it into the back of the tile (lots call this back buttering).

It would be good to still hit the epoxy floor with a sander to rough it up and bit and break the surface to give it a better grab.

Another option would be to put down a cleavage membrane or uncoupling membrane first and tile over that.

I would look at Nobel for a good membrane or ditra for an uncoupling membrane.

Most companies won't like hearing that you split up their epoxy mixes just fyi. You will be on your own to make sure you get the ratios exactly correct. If the ratio is off it very well won't work right.

 

[R-mm]

My current thinking - influenced by you and echoed by the trade counter - is to
1. De-grease, scrape loose epoxy (very little)
2. Apply Laticrete Prime & Bond
3. Set tile with Laticrete 254

 

[duneslider]

That will stick better than the epoxy is stuck to the concrete I suspect.

I know they sell prime and bond to use to install tile over the top of tile. Laticrete is always my go to for difficult installs, as well as all others. That's the only stuff I used in my own house.

 

[Armorpoxy]

Remember that if you don't remove the epoxy coating, then if/when the epoxy peels or fails your floor will come up with it, so for this reason it's always best to install onto bare concrete.

 

[R-mm]

I get that, thanks. Calculated risk for me.

 

[R-mm]

The sell sheet on 254 says its coverage ranges by trowel size which makes sense, the range works out to about 60-90 sqft per 50lb bag. Since they aren't exactly giving it away I wanted to get a gut check from experienced tilers that it sounds about right. I'm tiling about 550 sqft so I'd purchase about 7 bags to start?

 

[ace10]

Can you do a small test on just a couple of sqft? Just to get the hang of working with the products you've chosed and to see if the bond will be good.

When I was heading into my garage tile project, we did a bunch of tests. Mostly focused on the concrete profiling and types of thinsets.

You don't want to set a couple thousand tile and then find you have a problem.

Which, by the way, is a **** ton of tiles. You using a anti-lippage system?

 

[R-mm]

I haven't decided on that, is there a system you recommend? These are 4x8 tiles.

For sure I will be going slow and doing a test.

 

[R-mm]

For a garage do you all think the added cost and difficulty of epoxy grout is worth while?

I absolutely use the space hard and often have oil and things dripping on the floor. I had planned to use a dark color either way, such as Laticrete 45 Raven

 

[duneslider]

I have gone back and forth through the years when it comes to epoxy grout. There are also levels of epoxy grout, let's just assume we are talking about something fairly user friendly like Laticrete spectraloc.

There are two things that happen to grout. 1. They get stained. 2. They get really dirty. I could write a book on this but happens in most peoples homes is both. The grout gets stained AND gets really dirty. Sealers prevent staining but don't do anything for the dirty part.

It is people's cleaning process that typically creates the "really dirty" grout issue. Epoxy grout can still get really dirty and require extensive cleaning, it is just much more resistant to staining and ends up being a bit easier to deep clean.

I have gotten to where I hate installing epoxy grout. It is more work and is more expensive. Some of the newer "pre-mixed" grouts are really nice and easier to use than epoxy with nearly the same results. I just built my own house and I chose not to use epoxy this time because I hate installing it. I have a mixture of Laticrete Permacolor (most areas) and some high traffic areas are the "pre-mixed" variety.

If you are doing a black grout (raven) then if this were me, I would do Permacolor and be done with it. The biggest culprit in dirty grout is mud...when you mix dirt and dust with water it turns to mud and sticks to grout. If you get all the dirt and dust off the grout and then mop with as little water as possible you end up NOT creating mud and grout stays looking good much longer.

 

[duneslider]

I don't think I would use an anti-lippage system on 4x8 tile...you would go broke and that would take FOREVER.

Its gonna take forever laying 4x8 in a garage anyway. You won't have to worry about how slippery it is in there though!

Also, that tile would **** to grout with an epoxy grout. You still may want to look at a grout release to use with that tile.

 

[R-mm]

Thanks for all that feedback. The tile mfgr who sells mostly to home and commercial auto shops commented that most of their customers use a cement grout. I am leaning that way with a dark color such as Permacolor Raven.

 

[ace10]

I've used anti-lippage on smaller tiles, but that's in bathrooms. It would get spendy on a big job with 4x8 pieces.

For grout, I've been very pleased with Mapei Flexcolor CQ in my garage. Fluids have wiped up, so far. It's premixed and I did not use any additional sealer. I did use a releaser on the tiles, because a test showed it was going to be difficult to get it completely off my high grip surface and only me doing the work.

You really go do some testing to see how the products are going to work and how good you can get at setting them.

 

[R-mm]

The Prime and Bond data sheet notes that self leveling products have to be applied within 72 hours but doesn't say anything about simply tiling over with mortar. Do you all think its safe to presume there is not a time limit on this? I called Laticrete and they basically read the data sheet back to me...

Drying Time
Allow PRIME-N-BOND to dry before applying a polymer
modified mortar. The minimum drying time is 15 – 60
minutes depending on the substrate and environmental
conditions. When used as primer for self-leveling
products (e.g. NXT LEVEL) allow 2 – 5 hours for PRIME-
N-BOND to dry before self-leveling products are poured.

If PRIME-N-BOND dries for more than 72 hours before
application of the self-leveling cement, clean the surface,
re-apply an additional coat of PRIME-N-BOND and
install the self-leveling products within 72 hours. Mix and
install self-leveling products per LATICRETE product
data sheet and installation instructions.

https://cdn.laticrete.com/~/media/product-documents/product-data-sheets/ds-307.ashx?sc_lang=en&vs=1&d=20200507T173743Z

 

[duneslider]

You don't need to worry about it if you aren't using nxt, if you are just using thinset it will be fine. The only issue I would say is if you have a lot of traffic over the primed area it could cause problems. The primer isn't made to be a wear material so if you won't hold up well to a lot of traffic. If you think you might be taking some time to get this done you might want to just prime half the area and then keep the traffic to the non-primed area until you get a path tiled that can become your traffic area.

 

[R-mm]

Thanks. I don't need to walk on the garage at all, I just wanted to be efficient and prime as much as I can even if my actual tiling will proceed slowly as I get my legs under me.