Tiling over un-level self leveling concrete


Old 10-07-13, 10:12 AM
Thread Starter
Join Date: Oct 2013
Location: USA
Posts: 6
Received 0 Votes on 0 Posts
Tiling over un-level self leveling concrete

I have a rather large room... 19x15.. 285 square feet and I attempted as a DIY project to install electric heated floor.

On a concrete slab I first installed synthetic cork, the electric mat and then self leveling concrete. Unfortunately the SLC did not "flow" as they said and now the floor has ripples in some places.

What is the best way to fix this?

I have been told that a "mud job" is the only way to go to make sure the floor is level but I called a tile contractor in today and he said he could put a skim coat (of thinset?) over the floor and then do a normal thinset job.

If it helps the tiles are 12x24 inch tiles that will be layed in a brick patern with minimal spacing.

Thanks in advance!
Sponsored Links
Old 10-07-13, 04:56 PM
Join Date: Jan 2012
Location: usa
Posts: 135
Received 0 Votes on 0 Posts
not sure if "synthetic cork" is a good underlayment for tile. did the slc stick to it? you can repour slc over slc using their primer, to a extent you can use thinset to repair any uneveness using a straight edge to smooth things out. A 12x24 tile.. floor needs to be perfectly flat
Old 10-07-13, 05:00 PM
czizzi's Avatar
Join Date: Jul 2007
Location: USA
Posts: 7,376
Received 9 Votes on 7 Posts
The screed should have happened while you were pouring the SLC over such a wide area. Also, how is the cork adhered in the mix? Is it just a mat floating over the slab or is it glued/mortared in place. Usually if you pour SLC on concrete, you need to prime the concrete first. If you pour SLC over a subfloor, you are supposed to prime and install wire lath to hold the compound tight to the wood. Don't frankly know how it will interact with the cork.

You will need an extremely flat surface to lay 12x24 tile or you will have all sorts of headaches with the edges not setting at the same height causing high and low spots. Using a brick pattern will make keeping the tiles level with the adjacent ones even more difficult to attain.

You will need a long reliable straight edge so you can make adjustments to the SLC. It will scrape down in the high spots but it will fight you along the way. You can also take a flashlight and lay it on the ground. The shadows cast will show you where you need to make adjustments. I would also plan on at least a 2nd pour of SLC to smooth out the first pour now that you know you need to work the compound as you make your pour. The long straight edge will help you drag and move the SLC around to fill the voids.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: