Tile in a Basement

[quackattack99]

Hey all! New to this site but will be here often! I appreciate all your help in advance, I was curious to know if anyone had any advice on putting ceramic tile in a basement. My floor is smooth now and was wondering what I needed to do to “rough it up” or if it was ok to just spread mortar on the smooth floor? Also I have a small hairline crack in the floor that runs nearly half of the floor area. How do I go about repairing that or installing some type of membrane to prevent my grout/tile from cracking?

Thank you again for all your help!

GB

[bbcamp]

Hi, GB!

If by "smooth" you mean that there is a bit of shine on the surface, then yes, you probably will want to scuff that up a little. But of more importance, does the slab absorb water? If it was sealed sometime in the past, it may not. Sprinkle some water on the floor and if it soaks in, your slab isn't sealed enough to worry about.

The hairline crack: Is it level on both sides of the crack? If not, you can apply an antifracture membrane over it. Look for Protect-o-wrap at your tile store. Follow their directions.

[quackattack99]

Hey bb, Not sure if it is sealed or not? I highly doubt it, we bought the house new from the builder in 2004 and I haven’t ever done anything with it. Are you saying I need to seal it?

The crack is even on both sides, I will see what the tile store has for the crack, I will see if they have protect-o-wrap. Thanks for that info!

[bbcamp]

No, you do not want the slab sealed. Do the water test to verify what you do have, then let us know what you found out.

[quackattack99]

Bob, Will do. I will do it tonight.

As far as "grinding" the concrete down, how do I go abou that?

[bbcamp]

Rent a floor grinder, or use an angle grinder. You're getting ahead of yourself, though. If you are the onliest persons to live in that house, and you didn't seal the slab, it probably wasn't sealed.

[cx]

Welcome, GB. Please put those initials in a permanent signature line so's they appear in each post for us to remember, eh?

It's quite common in some regions for all concrete slabs to be sealed immediately after pouring as an aid to proper curing. Do the water test that Injineer Bob recommended to be sure you don't have that situation. Izza cheap test, eh?

My opinion; worth price charged.

[quackattack99]

I am pretty sure it isn't sealed. The drywaller (my bro in law) was there all weekend and he spit all over the floor and everywhere he spit soaked right into the floor. Gotta love family and there great manners!

[bbcamp]

Spit's different.

[quackattack99]

BB, Ok I went home at lunch and did the test…..The sprinkles of water didn’t absorb immediately but within 30 to 45 mins it had.

Is this ok? I am the original owner and know that I haven’t sealed it before. None of the homes in our region are sealed either. I live in Missouri by the way!

[bbcamp]

If the water didn't bead, and it didn't evaporate (but really sank into the concrete), then I'd say your slab is not sealed.

[quackattack99]

Well my floor is definitely not sealed. So now to my next question….do I need to rough up the slick finish on the floor before I mortar it? Thank you in advance for your help.

[cx]

Always a good eye-dee to rough up the slick concrete finish, GB

My opinion; worth price charged.

[quackattack99]

CX----whats the best way to go about roughing it up???

Thanks!

[George K]

I roughed up my concrete basement floor with a scarifier. It is much better than an angle grinder or one of those two disk concrete grinders that seemed to only polish the surface.