Mapei Mapeguard UM Underlayment Membrane (323 sq. ft. Roll)


50 in stock


Mapei Mapeguard UM Underlayment Membrane (323 sq. ft. Roll)

Mapei’s Mapeguard UM is a lightweight uncoupling mat for use under ceramic tile and stone installations and can also work as a waterproofing and vapor-pressure-equalizing underlayment. This versatile underlayment membrane can perform on the most challenging substrate surfaces, such as young concrete and single-layer 3/4″ plywood floors, in both commercial and residential applications. The unique engineered tri-layered design of Mapeguard UM absorbs lateral stress from the substrate without transferring this force to the tile or stone, which maintains exceptional bonds.


  • Prevents transmission of in-plane substrate cracks up to 1/8″ (3 mm)
  • Recommended for use with polymer-modified mortars
  • Fast Track Ready – approved for use over young (green) concrete and mortar beds
  • Time-saving: Embed membrane then install tile immediately
  • Engineered cavity design allows easy single-pass filling of surface core with less mortar
  • Uncoupling, waterproofing and water vapor membrane up to 25 lbs. (11,3 kg) MVER and 100% relative humidity
  • Compression resistance to support rolling loads
  • Approved for radiant-heating applications
  • Light green, translucent color shows mortar coverage under membrane
  • Reduced “roll memory” and unique tri-layer construction keep membrane flat
  • Easy to cut with standard utility knife
  • Chalk and laser lines easily visible on surface
  • Mesh-fabric top layer makes it easy to fill cavities with mortar

Suitable Substrates:

  • Concrete
  • Cement mortar beds, self-leveling underlayment and leveling coats
  • Young (green) concrete
  • Industry-approved exterior-grade plywood and APA Sturd-I-Floor, Exposure 1 OSB (interior, dry areas only)
  • Approved backer units – see manufacturer’s installation guidelines
  • Cement terrazzo (properly prepared interior only)
  • Existing ceramic tile or stone (properly prepared interior only)
  • Radiant-heat systems
  • Existing, properly prepared vinyl flooring – vinyl composition tile (VCT), non-cushioned paper-backed/felt-backed sheet vinyl, luxury vinyl tile/plank (LVT/LVP)
  • Epoxy terrazzo (with appropriate bond testing – interior only)
  • Gypsum underlayment or lightweight concrete

At Dmsofts, we are dedicated to providing our customers with the best service possible.

We offer free shipping and 1 to 2 days handling on all orders.

We strive to process all orders within 2-4 business days.

Our transit time is 5-7 business days.

We are not responsible for any delays due to weather, natural disasters, holidays, or any other circumstances beyond our control. If you have any questions about our shipping policy, please contact us at