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Mapeguard UM Underlayment Membrane - 54 sq. ft. (5 m²) Roll

Mapeguard UM Underlayment Membrane - 54 sq. ft. (5 m²) Roll

Regular price $96.00
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Mapeguard UM Underlayment Membrane - 54 sq. ft. (5 m²) Roll by Mapei

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.


  • Dimensions: 39.4 in x 16.4 ft
  • 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