Tile Subfloor Underlayment: What’s the Best- PROFLEX MSC 90

American Flooring Distributors offers the best resources for a tile subfloor underlayment. When looking to prevent cracks that will ultimately transfer to the tile, use PROFLEX MSC 90 Sound Control. PROFLEX MSC 90 also provides state of the art sound insulation under tile.

Tile Subfloor: What’s the Best/Worst Ceramic Tile Underlayment?.

What to use as ceramic tile underlayment?  How about saying tile backerboard and leaving it at that?

Really, if you ever have questions about whether a material can be used as tile subfloor underlayment, backer board is always your answer.  It can be installed on top of just about anything, and tile loves it.

But ours is not a perfect world, so we need to consider whether tile can be installed on sheet vinyl flooring, tile vinyl, plywood, concrete slab, and so on.

  • Best Tile Underlayment? Backerboard–specifically DensShield by Georgia-Pacific. With Proflex MSC 90 Soundproofing underlayment.  That’s my opinion.
  • Worst Tile Underlayment? OSB wood.  Drywall.  The list goes on.

PROFLEX™ MSC 90 is a 90 mil composite underlayment consisting of a rubberized membrane laminated to a high strength reinforcing fabric on the face and a siliconized release sheet on the adhesive side. Proflex MSC is designed for full coverage crack suppression and sound control. PROFLEX™ MSC 90 is specially designed to be used under approved thinsets, mortars, and adhesives for interior and exterior applications of ceramic tile, stone, and brick, and for interior applications of wood flooring to eliminate the transmission of cracks and to reduce sound transmission. Other applications also may be suitable. To eliminate cracks in finished floor work, the product should be applied to the entire substrate prior to the installation of the finished flooring for crack suppression.


  • Easy and fast to install with standard tools
  • Ready for tiling immediately after installation
  • Crack and joint isolation up to 3/8″
  • Crack Suppression
  • Sound Control
  • Moisture Vapor Protection up to 5# per 1000 sq.ft/24 hr
  • *CaCl2 Test (see installation instructions)


  • Concrete (Poured, Prestressed, Precast)
  • Cured (Mortar Beds, Self Leveling Compounds, Gypcrete)
  • Concrete Backerboards
  • Wood (Exterior Grade Plywood, Hardwood, Toungue and Groove, OSB)


  • 100 sq.ft. per roll
  • 3′ x 33.3′ roll boxed