ARDEX SKM Skim Finish – Skim Coat Patch & Finishing Underlayment is a trowelable patch and skim coat for use over interior concrete, wood, moisture-insensitive tile and stone, cutback and other non-water soluble adhesive residues on concrete. ARDEX SKM will provide a permanent, smooth, durable finish prior to the installation of most floor coverings. ARDEX SKM hardens quickly, is easy to apply and dries fast without shrinking, cracking or spalling.