saw cut concrete - Contractor Talk - Professional Construction and Remodeling Forum

KoryEmma · 11-08-2005, 11:37 PM

Question for you hardcore tile guys. I am a hard wood guy that does some tile. Question is how would you go about tiling a concrete floor with saw cuts? There are three cuts, two parallel and one at a 90 degree. The tile brakes out mint using two cuts at 90, But the parallel cut breaks out about 3 inches in in a 12 inch tile. I know they make caulking to match the grout for movement on saw cut floors but what do I do about the tile that goes over the cut.If I put thin set on both sides of the cut wont the tile break on the cut if the floor moves?could I set the 9 inch part and leave the rest free so if the slab moves it wont break the tile or will that just break them anyways? Also could I fill the cut and make a new one at the grout line and if so what do I fill the cut with?

Mike Finley · 11-08-2005, 11:42 PM

Well, the standard answer I have always been told is you have to leave a grout line over all expansion joints. I have also been told you can put a 6 inch wide strip of roofing felt over the expansion joint. A ditra type matt may also be the answer.

Or just lay carpeting instead.

K2 · 11-09-2005, 12:32 AM

My experience with saw cutting a slab is that if it is just a 3/4 inch cut it is only a recomendation for the slab to crack on that line. It doesn't mean it will crack along that line or that it will crack at all. If the slab is older than 1 year and is reinforced and is on stable soil it may have done all the movement and cracking that it will ever do. Look in those cut lines, you will probably see that some have cracked and some have not cracked.<P>
An example that might be easier to understand would be a concrete foundation with rebar in it . The rebar does absolutly nothing untill the foundation gets a 1/64 in. crack. Then the rebar goes under tension and holds the wall in that position for the next 1000 years. <P>
Anyway that's my opinion on the subject but i'm not a tile guy.

Tonkadad · 11-09-2005, 01:26 AM

I believe an isolation membrane would be appropriate in this circumstance. Google "John Bridge tile forum"

Basically you apply thinset to the concrete set the membrane in the thinset then thinset over the membrane and set the tile.

KoryEmma · 11-13-2005, 06:53 PM

Quote:

Originally Posted by Mike Finley

Well, the standard answer I have always been told is you have to leave a grout line over all expansion joints. I have also been told you can put a 6 inch wide strip of roofing felt over the expansion joint. A ditra type matt may also be the answer.

Or just lay carpeting instead.

But carpet sucks in a kitchen