Malcolm Hoar wrote:
I have an outside (but sheltered) entrance porch. The cement
finish was badly stained by some planters and it looks pretty
crappy despite considerable efforts with a pressure washer
and various chemical treatments.

So I'm starting to think about covering the mess with some
decent granite or slate tiles. Any general pointers (do's
and don'ts) would be most welcome.

However, I do have one specific concern -- the area in
question comprises of 3 concrete slabs with expansion
joints. To make matters worse, one of these runs at a
45 degree angle to primary axis of the entrance. One
of these joints shows some signs of past movement. I
suspect the outside slab settled a little probably
soon after construction (about 17 years ago). There's
an 1/8th inch crack along the joint. I think it's now
stable and has not visibly moved in the 3 years I have
owned this house.

How should I handle these joints? Initially, I assumed
that tiling over the joints would prove fatal and that
I would have to tile each slab seperately. The 45 degree
joint would make the effect less than wonderful. But
maybe it's okay to tile over the joints if I install
some kind of isolation layer?

I'm sure that plenty of folks have tried tiling over
old concrete pation, pathways etc. What worked, didn't
work, and how did you handle the existing joints?




I tiled my concrete patio slab several years ago and here's what I did.
Fill the joints with the thinset mortar that you use to adhere the tile,
cover the whole slab with one of the several anti-fracture membranes
available these days, install the tile using latex modified thinset, and
keep your fingers crossed.

I've always figured that putting a hard yet somewhat brittle finish like
ceramic tile over anything that has potential for movement is a crap
shoot. But the things I mentioned can certainly help towards mitigating
the possibility of cracking. It's been about 2 years since I did mine
and no cracks, knock on wood. Some grout came loose in a spot or two
next to the wall.