Leveling concrete porch and installing slate tile. - Contractor Talk - Professional Construction and Remodeling Forum

Rickle · 08-24-2009, 06:03 PM

Hi, I have a project that involves leveling a concrete porch and installing slate tiles. The porch was built out of level by about 2.5 inches on one corner. It looks bad and the home owners want it fixed.

My plan is to build it up/ level it with mortar mix and install the tile in the usual manner. I'm not a tile layer so I'm not sure if using mortar mix is a good way to go.

--Rick

gumba · 08-24-2009, 10:42 PM

See if you cna determine flat plan by setting screets with wood shim from the deepest part of the low corner to a main area in the rest of the porch that would serve as a good basis to merge your low corner with the rest of the porch. Most likely this will not be perfectly level but this should serve to resolve into a flat plane. Rember screeting mud requires at least an 1 1/4" of bed, anything lower will not work well.

Rickle · 08-25-2009, 08:12 AM

But is it ok to use mortar mix for this?

jarvis design · 08-26-2009, 09:48 PM

I had to do the same thing with my own front step which was 2 1/2" off level side to side. I framed around it (level), put in some wire, and used mortor mix. I also poured a new step on top of that and a pad beside.
Because its Canada, I was concerned with too much moisture getting into the concrete so I installed ditra (with kerdi) to waterproof the entire assembly before tiling. I used a 12"x24" porcelain tile and used laticrete spectralock epoxy grout.
It's been a year (with a damn cold winter!) - looks like the day I put it in!

Bud Cline · 08-26-2009, 11:01 PM

Sand mix is used, not mortar mix. Mortar mix contains lime and will be somewhat sticky, lime will cause the straightedge to drag. The minimum is 3/4" but striving for 1-1/4" is desired.

The sand mix is mixed very dry then packed (NOT POURED) into place. The straightedge ("screed") is dragged over the surface to achieve the plane. Steel pipes can be used to establish level and to drag the straightedge on top of. Once the surface is flat the pipes are removed and the voids filled and scraped flat to match the surface.

A surface primer is required. Liquid concrete primer will work. Thinset tile mortar can also be used either thrown down dry or mixed and trowelled to bond the sand mix to the existing concrete.

olzo55 · 08-30-2009, 12:59 PM

just a thought. did this slab sink or was it really built like that? I repaired a porch where the slab sank . the slab was mudjacked to fill any voids below before any tile work was done. tap the slab in that area to hear if it sounds hollow. fix it before tiling. you'll be glad you did.

jarvis design · 08-30-2009, 09:50 PM

Quote:

Originally Posted by olzo55

just a thought. did this slab sink or was it really built like that? I repaired a porch where the slab sank . the slab was mudjacked to fill any voids below before any tile work was done. tap the slab in that area to hear if it sounds hollow. fix it before tiling. you'll be glad you did.

When I did mine it had sunk. As part of the project I re-landscaped the area to ensure proper drainage - which before directed all the water to under the slab that had sunk.

Rickle · 09-03-2009, 02:45 PM

There was no sign of it sinking any where, the brick was level but the pad was formed and poured on top. It was obviously made that way. I think the form sagged on them during the pour and they went with it any way.

As describe in an other post I anchored leveling boards to the perimeter and used the mortar mix. Turned out great.

Rickle · 09-04-2009, 07:19 PM

Here's a pic of the result. Not to bad for a rookie tile setter eh?