I have a concrete slab patio (roughly 25′ x 10′) that is in pretty good shape. My wife and I have thought about covering it with stone or porcelain tile. The problem is that the concrete pad slopes toward the house. (It looks like the previous owner poured the pad himself.) The pad itself doesn’t appear to be sinking. Can I “fix” the slope of the pad by adjusting the thickness of the mortar when I lay the stone? At most I think we’re dealing with about a half-inch difference between the low and high spots. Any thoughts would be great.
Thanks.
Replies
Well, you're really talking about 1 1/2" then, since you're 1/2" low at the house, plus you should really be pitching away from the house a minimum of 1/8" (preferably 1/4") per foot. You'll therefore need to raise the house end 1/2" to get level, plus another 1" plus to get slope- that's alot of extra mortar.
Bob
but its not alot of concrete. if the pad has 100% 0 cracks you can pour right on to of it. after you form it etch the concrete and apply a bonding agent ( i make mine with pure portland and h20 to a slurry) concrete on the shallow end should be at least 1 inch.
if you live in a freezing climate there is an additive to put in thinset to prevent frost from dammaging tile.
Thanks for the replies. So are you saying I use the bonding agent mixture (portland and H20) to fix the slope problem, then lay the tile on that after it cures? That sounds like a good idea.
Also, if I inspect the slab more closely and notice small cracks (less than 1/16"), are you saying I can't use this method? If there are cracks, what do I do?
Thanks again.
no man you gotta pour a slab 2 1/2 in at the house 1 in away from the house to reslope. the bonding agent is what i use to join the 2. there are commercial latex fortified ones but i seen the portland mix used to bond concrete to spancrete and have been using ever since.
if you have cracks at all theyll show up again no matter how thick you go. I was just triing to save you the demmo of a mispoured slab.
Thanks for your help. I'll go research supplies this weekend.
Shawn