unlevel concrete floor

Q. We had a 40'x12' concrete floor poured 4" thick with wire mesh and rebar over gravel with perimeter footings for a one story sunroom attached to our existing house. The finish was not leveled properly and has many valleys and two high spots in the middle of the floor. What would be the best way to level the floor so that large ceramic tile can be set after the framing is done?

A. You can use a product from Ardex called K-15. ARDEX K 15 is a self-leveling Portland cement-based underlayment. Use to level and smooth interior concrete, terrazzo, quarry and ceramic tile substrates – on, above or below grade. Can also be used over cutback adhesive residue, metal decking, and wooden substrates. ARDEX K 15 will level and smooth concrete and other substrates prior to the installation of resilient flooring, ceramic tile, carpeting, wood parquet, athletic floors, etc. ARDEX
K 15 can be used for a wide variety of indoor applications above, on, or below grade, including: (new construction) unlevel concrete, rough concrete, rained-on concrete, frozen concrete, unfinished concrete, rough-screeded concrete, and camber problems; (rehabilitation projects) terrazzo, quarry and ceramic tile, old concrete, smoothing of floors over cutback and non water-soluble adhesive residues on concrete, wooden floors, and steel decking.

Description
Designed specifically for fast leveling of floors, ARDEX K 15 provides a durable, flat and smooth floor surface with minimum labor and installation time. ARDEX K 15 is recommended or specified by many quality flooring manufacturers, architects, and contractors. Pourable or pumpable when mixed with water. Seeks its own level and produces a smooth, flat, hard surface. Hardens quickly and dries fast without shrinking, cracking, or spalling.

Those are a couple paragraphs from their spec sheet.

Click HERE for the rest of the spec sheet and a further description of this product.

I have used this product. It is very easy to use and very self-leveling.