DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Flooring (http://www.diychatroom.com/f5/)
-   -   Ceramic on Concrete (http://www.diychatroom.com/f5/ceramic-concrete-25191/)

DanTheMan 08-14-2008 10:45 AM

Ceramic on Concrete
 
I'm finishing my basement bathroom and plan on laying down ceramic tile with the same used as baseboards. I've laid ceramic in my last house, but it was over a plywood subfloor. I've laid a fireplace pad over concrete before and never made any special considerations compared to how I did it on plywood. There was no issues that I heard from that (was a friend's).

Before I do a whole bathroom, I thought I'd post here to see if I can use the thinset mortar as I did before and lay the tiles directly on the concrete. And also use the same for putting the tiles against the drywall for a 'baseboard'. The remaining flooring will be laminate and I'm trying to keep everything at the same level.

Also, do I just cut 5" or whatever height off regular 12x12 tiles to make the baseboard and put the cut edge down? I have a wet saw, so it should make for straight clean cuts.

And just to note that I have no moisture problems in my basement. It's a new construction less than 2 yrs old.

ccarlisle 08-14-2008 12:35 PM

Well, if you've done your reading here and on other boards, you'll have gathered that tiling on concrete is a problem that has already been solved by the use of an anti-fracture membrane, call it what you will, that in the case of the one that many prefer, Ditra, only adds about 1/8" to your floor height.

So most of us recommend that practice, as do tiling protocols that most of us adhere to for professional purposes. You may not have moisture now (just how do you know that) but you probably will in the future. You may have a perfect slab now - but won't down the line. So, in the end you can do what you want, but you would have expected this answer from here or anywhere else...

Yes, cut the tiles in half, or at whatever height you want and put the cut side down, then caulk, not thinset opr grout, changes of plane.

floorgal 08-19-2008 01:41 AM

ditra would be best, but if cost is an issue, then yes you can use a MODIFIED thinset (mortar) on the slab floor. but it is not suggested using thinset on drywall as the moisture and alkilines in the thinset can damage the drywall. you should use a standard type 1 mastic for adhering tile to drywall. you may also consider using a 1/4"x 3/8" square-notched trowel for laying the tile on the slab. if you sprinkle some water on the slab and it wants to absorb within about 10-20 seconds, use the lager trowel or as a variation, LIGHTLY dampen a sponge with water and swipe over the area you are immediately tiling- like a 3'x3' area or so. this is because the concrete is still so absorbant and not fully cured ( as it takes Years and Years to cure) that the moisture in the thinset can be absorbed too quickly causing your tiles not to set properly which may lead to loose tiles. hope this helps!

DanTheMan 08-19-2008 06:45 AM

Quote:

Originally Posted by floorgal (Post 149862)
ditra would be best, but if cost is an issue, then yes you can use a MODIFIED thinset (mortar) on the slab floor. but it is not suggested using thinset on drywall as the moisture and alkilines in the thinset can damage the drywall. you should use a standard type 1 mastic for adhering tile to drywall. you may also consider using a 1/4"x 3/8" square-notched trowel for laying the tile on the slab. if you sprinkle some water on the slab and it wants to absorb within about 10-20 seconds, use the lager trowel or as a variation, LIGHTLY dampen a sponge with water and swipe over the area you are immediately tiling- like a 3'x3' area or so. this is because the concrete is still so absorbant and not fully cured ( as it takes Years and Years to cure) that the moisture in the thinset can be absorbed too quickly causing your tiles not to set properly which may lead to loose tiles. hope this helps!

Thanks! I just wrapped up the plumbing and I'm working on mudding and taping right now. I'm going to price out Ditra, but I'm also not going to double the cost of laying my floor for it either. I haven't priced it out yet, but I've heard it ranging from $1.50-$3.00 a sq. foot. If I don't use Ditra, I'll certainly use your suggestions to make sure the cement doesn't wick out the moisture from the thinset. I only need 60 sq. ft., so maybe it won't be too expensive.

ccarlisle 08-19-2008 07:51 AM

floorgal:
"...but it is not suggested using thinset on drywall as the moisture and alkilines in the thinset can damage the drywall."

:huh:

The manufacturers of Ditra recommend thinsetting Kerdi to drywall. If thinset could damage drywall, why would they do that?
Are "alkilines" like...bugs... or mould?

:whistling2:

DanTheMan 08-19-2008 10:37 AM

Quote:

Originally Posted by ccarlisle (Post 149894)
floorgal:
"...but it is not suggested using thinset on drywall as the moisture and alkilines in the thinset can damage the drywall."

:huh:

The manufacturers of Ditra recommend thinsetting Kerdi to drywall. If thinset could damage drywall, why would they do that?
Are "alkilines like...bugs... or mould?

:whistling2:

Do you know off-hand what Ditra costs around these parts? We're pretty close (New Brunswick) so pricing shouldn't be too far off. I've been too busy lately to price it out. It'll be another few weeks before I'm done the drywall and ready to tile.

Any special type of caulking to adhere the tiles to drywall? Should I avoid priming/painting that part (ie. put the tiles up before paint)?

Thanks for the tips!

comp1911 08-19-2008 11:07 AM

Not in Canada but I just bought a 54 square foot roll of Ditra at Home Depot and it was $83.00.

floorgal 08-19-2008 12:02 PM

my bad! i meant you cannot use the modified thinsets because they have too much alkaline (higher ph) in them than the regular dry-set (un modified ) mortars. and what exactly are alkalines- hmmm. not sure. i believe it is a agent that is used for bonding. maybe not. i know that manufacturers of concrete backerboards suggest the use of alkaline-resistant board tape. regular drywall mesh tape would rot or dissolve due to the alkalines. does that help ??? i'm still confused.http://www.diychatroom.com/images/icons/icon12.gif

comp1911 08-19-2008 01:05 PM

The Schluter instructions state that you should use a non-modified thinset between the concrete and Ditra and also between the Ditra and tile.

http://www.schluter.com/media/brochu...k-2008-ENG.pdf

ccarlisle 08-19-2008 01:34 PM

Ditra is carried by Home Depot but they normally only stock two size rolls: the 5 meter (or 54 sq ft) roll, and the 30 meter (or 323 sq ft) rolls, but depends on the store. There is an in-between size, the 150 sqft roll too.

Prices from 2007 are between US$2.34 and $2.63 per sq ft.

There are several sub-distributors on this board who stock Ditra and can sell you less than the full-roll. Do a search. I can't remember who it was who said he could undersell any HD and I think he was on the West Coast.


All times are GMT -5. The time now is 11:41 PM.