Guidance on floor prep for porcelain

[84944Redline]

Hi everyone,

I'm on information overload at this point and would appreciate some input to get me back on track. I've searched this site a lot and read countless pages on what others have done. I've also checked out the John Bridge site that people recommended.

So here's where I'm at...which is where I've been for over a year now. I would like to put down porcelain tile in my garage. I have done my research and feel this is best suited for what I want. I've found 12" X 24" tiles made by the same mfg. that come in gray and off white. Pattern will be 24" x 24" checkered.
http://www.lowes.com/pd_399387-3469...ey&pl=1&currentURL=?Ntt=mitte+grey&facetInfo=
http://www.lowes.com/pd_399382-3469...e&pl=1&currentURL=?Ntt=mitte+white&facetInfo=

My questions and request for guidance are not "in general", but more specific.

Quick background...garage is approx. 1,000 sq. ft. and insulated. I live in Nebraska and have weather ranging from hot and humid to freezing and snow. I do have a NG heater installed. I like to keep the garage anywhere from say 45 - 55 degrees depending on use. This past winter, the garage stayed in this range without the heater even being turned on.

The house is going on 15 years old and we are not the original owners. I did the sealer test on spots in areas which don't get a lot of traffic. I poured about a 4" circle of water and it beaded up immediately. After 5 minutes it was still beaded up. I wiped the spot with a rag and the concrete was darker, so I think that indicates there was at least some penetration.

The floor is the last of my "garage renovation". I've got signs and cabinets and such already hung up. For these reasons I am hesitant to rent a machine to diamond grind my floor - I don't want all the dust kicked up. Sorry if this reasoning sounds silly...that's just the clean freak in me. I know there are vacuums and dust collection systems to rent or buy to help with that, but I'd like to avoid if possible.

Since I'd like to do tile, is etching the cement acceptable? I see feedback strongly suggesting doing so for epoxy, but what about for tile? I'm trying to gather information as to how to correctly remove the sealer and not sure that muriatic acid alone will do it.

Since etching won't achieve the same result as grinding, would using a better quality thinset compensate for it? Going with Keralastic/Kerabond is very expensive for my size floor. I've seen Versabond and Flexbond praised about on the John Bridge site threads. And what about Keraply/Keraset?

I appreciate any feedback - thank you all!!!

 

[Shea]

It sounds like your slab has some sort of sealer such as a "cure and seal" or was power troweled very smooth. If it's a sealer then an acid etch will not work. The sealer will prevent the acid from contacting the concrete and acid doesn't break down sealer. If that is the case you will need to grind. One thing you can do is have someone shot blast the surface. That method is almost dustless compared to grinding.

If you think it's just a dense power troweled surface then you can try some acid in an inconspicuous spot to see how it works.

 

[84944Redline]

It's a pretty smooth finish. The neighbor (who used to be friends with the previous owners) even warned me when we first moved in to be careful when the floor gets wet because it becomes very slippery.

I was thinking of trying out the muriatic acid just to see if it'll work. Is it correct that if I see it foam, then that means it's doing the job? And if the concrete has a sealer, will there be any reaction at all?

I've come across some threads were people mentioned going the shot-blasting route, but don't know many specifics about it. I'll check that out and see if anyone local rents them.

 

[84944Redline]

Here are a couple of pictures of a spot I put muriatic acid on. I did it full strength just to see how it would work. It foamed up like crazy into a yellow-greenish blob. I let it sit until the bubbling stopped (less than a minute) and then neutralized it with some vinegar. Once I washed the area, I ran a metal bristle brush over a couple of times. You can see a smaller inner area that's lighter - that's the 100% acid. The larger outer ring resulted after I put vinegar to neutralize the acid.

This is the same spot where I tried the water bead test. So since there's a noticeable difference visually, as well as by touch - will muriatic acid be enough to etch the floor for putting down tile?

 

[bobscogin]

Vinegar won't neutralize acid. It is acid. I don't think you want to etch with full strength acid. Do more research.

Bob

 

[84944Redline]

Well, I feel like an idiot...not sure why I had in my head to use vinegar on this small test. :-/

If I were to use muriatic acid to etch the entire floor, I know to definitely dilute it with water, and I do know there is a lot of caution when using this stuff. And for neutralizing it, I planned to use baking soda.

Do the pictures validate acid etching will suffice? I guess at this point the answer is probably, but diamond grinding or shot blasting will be better.

Each time I build enough encouragement to get going with this project, I end up stepping back thinking I need to wait and read more about what other's have done.

Maybe I just need to say the hell with procrastinating and get to work with etching the floor with muriatic acid, pick up the tile and Versabond, then start laying tile.