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Mapei Mapeguard UM35 Decoupling Membrane

£10.00£244.73 (inc VAT)



Mapei Mapeguard UM35 Decoupling Membrane is for installation on internal and external substrates as an uncoupling and anti-fracture membrane for laying ceramic and stone flooring on difficult, cracked substrates and on substrates that are not fully cured, and without having to copy the layout of control joints and expansion joints (as defined in UNI 11493-1 and UNI 11714-1) in the substrate.

Available as standard in rolls measuring 30m x 1m. Per square metre rate also available – this is supplied as a single roll when multiple metres are ordered.

Mapei Mapeguard UM35 is suitable for waterproofing balconies and terraces since it creates an uncoupling and vapour compensation layer on damp substrates and/or on substrates that are not fully cured.

Mapei Mapeguard UM35 is a waterproof uncoupling and anti-fracture membrane that allows moisture in the underlying layers to be released. It is suitable for installing ceramic and stone tiles, including when overlaying existing flooring.

Mapei Mapeguard UM35 Decoupling Membrane may be used in the following settings:

  • new residential buildings and residential buildings being renovated;
  • commercial settings;
  • hospitals, hotels;
  • balconies and terraces;
  • bathrooms.

It is also suitable for use on these types of substrates:

  • concrete;
  • cementitious screeds;
  • cementitious screeds with heating systems;
  • anhydrite screeds;
  • anhydrite screeds with heating systems;
  • old ceramic, resin and wood floorings

Technical Characteristics:
Mapei Mapeguard UM35 is a membrane made from a layer of honeycomb HDPE with a rough surface and polypropylene fabric backing. These characteristics improve the bond strength of adhesive applied on both sides of the membrane.

Crack control:
Mapei Mapeguard UM35 allows the control of cracks in the substrate, acting as an anti-fracture membrane and as an uncoupling element that prevents transmission of substrate cracks to the flooring.

Waterproofing properties:
Mapei Mapeguard UM35 Decoupling Membrane is completely waterproof with the capacity to protect substrates from infiltrations of water and increase their durability. May be used on internal and external surfaces in combination with Mapei Mapeguard ST Sealing Tape for sealing joints between the sheets and waterproofing critical areas (edges, cornes, etc).

Vapour control:
Thanks to the air channels on the back of the membrane, the moisture in the underlying layers can evaporate; The membrane is thus suitable for use on damp substrates and/or on substrates that are not fully cured, including in external surroundings.

Mechanical strength:
Mapei Mapeguard UM35 allows the distribution of stresses also on floorings subject to heavy loads; it is certified as EXTRA HEAVY COMMERCIAL RATING according to TCNA test reports complying with ASTM C 627 and is suitable for use in residential and commercial surroundings.

Even heat distribution:
Mapei Mapeguard UM35 Decoupling Membrane also guarantees that heat is distributed more evenly when applied on heated floors, including compact heated floors.

Mapei Mapeguard UM35 is semi transparent and this allows to verify the correct distribution of the adhesive underneath, as well as to easily locate the presence of potential elements passing through surfaces (such as drains), thus making the cutting of the membrane easier.

Improved Adhesion:
The special shape of the embosses offers a perfect mechanical bonding of the adhesive in order to obtain a high adhesion between the ceramic or stone covering and the membrane.


  • The substrate must have an adequate mechanical strength according to expected loads.
  • Do not use in correspondence with structural joints in the substrate.
  • Do not apply over cracks or joints subject to out-of-plane movement.
  • Do not apply directly over structural cracks and/or cracks wider than 3 mm.
  • Do not use tiles smaller than 5×5 cm.
  • For substrates with residual moisture, use Mapeguard ST Sealing Tape to seal joints between adjacent sheets of membrane.
  • Do not use on dry anhydrite substrates unless they have been treated beforehand with special primer such as Primer G or Eco Prim T Plus.
  • Do not apply directly on bitumen membranes.
  • Needs to be covered with stone or ceramic flooring material.
  • Do not use on lightweight screeds.

Application procedure:
To install Mapei Mapeguard UM35 membrane correctly, we recommend consulting the Installation Manual, which is linked below.

Product Datasheet Installation Manual

Click here to view this product on the manufacturers website.

Additional information

Weight N/A

30m x 1m Roll, 1m² Unit (supplied in continuous roll)