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?



--
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~|
| Malcolm Hoar "The more I practice, the luckier I get". |
| Gary Player. |
| http://www.malch.com/ Shpx gur PQN. |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~

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.

In article , Manster wrote:

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.

Thanks muchly for the comments. That all makes sense.

However, I've since realized that my job is further complicated
by the fact that tile plus thinset plus membrame will add
significant thickness. As a minimum, I'll need to shave that
amount off the siding to prevent it from wicking up any water.
And the drop (or lack of it) from the door threshold to the new
surface could create even worse moisture problems at the front
entrance.

Beginning to think about a good quality decorative epoxy
coating...

I did my garage floor 3 years ago with a cheap one part epoxy
paint. It hasn't lifted, flaked or chipped at all -- I
cannot see a single spec of bare cement. But water runnoff
from the vehicles has stained it pretty badly and sadly
it's starting to look pretty tatty. These products seem
to get pretty good reviews:

http://www.armorpoxy.com/

No rush if I go with an epoxy coating -- I'll wait for the
warmer weather next year and more reasonable cure times.

As you say, tile is going to be something of a crapshoot
which is not good given the amount of work installing the
tiles and addressing all of the potential moisture issues.

--
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~|
| Malcolm Hoar "The more I practice, the luckier I get". |
| Gary Player. |
| http://www.malch.com/ Shpx gur PQN. |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~