jimrutherford.com 1990-2016
Home Improvement:
Kitchen Electrical and Lighting The Computer Modeling Basement

Tile Floor Leveling

Or rather, “flattening.”

Once the NuHeat cable twas down and covered with thinset, we found out that the floor was not at all flat.  There was a distinct ridge in the plywood centered around a basement lally column. We hadn’t discovered this until the thinset part was all done.  It looked flat, but a 6 foot straightedge showed that we’d after flatten the floor.
A laser is used to get a reading of where the highest areas are.  Using these identically shaped and marked wooden blocks, I can see how far out of plane the floor is and also establish a new non-level plane that would require the least amount of self-leveler.
Here is how we created the same plane.  I made a square aluminum frame that stands on bolts in the corners as feet.  The frame is aligned to the spinning laser that is my reference plane.   There is another aluminum angle that rides on the frame as a screed.  This way I can pour self-leveler and then screed it to a plane.
At first, we tried self-leveling compound over the thinset.  Self leveler does NOT self-level.  It auto- smooths and that’s about it.  I needed a way to set a plane (didn’t care it it was level) and have the whole kitchen be on that plane.
Without moving the spinning laser, this process is repeated until the floor is pretty much covered with these plateaus.
You can see how flat the screeded self-leveler comes out.  We pour a little SLC, trowel it the full length of the screed, and then slowly draw the screed over it.  This creates a 10 foot by 10 foot plateau of SLC.
Although it looks like a patchwork, the resulting floor is quite flat and ready for the Ditra.