Mapei Mapeflex PU45

Non Hazardous
A single component, rapid hardening, paintable, thixotropic polyurethane sealant and adhesive with a high rate of elasticity.
Available in Boxes of 12 x 300ml Cartridges
From £149.70 £124.75
In stock
Only %1 left
Product Description

Please note, this product has a 3 - 4 week lead time for delivery. Please call our Sales Team for updates.

Mapei Mapeflex PU45 is a single component, rapid hardening, paintable, thixotropic polyurethane sealant and adhesive with a high rate of elasticity.

Best Uses

Mapeflex PU45 has been specially developed for sealing expansion and distribution joints in horizontal and vertical surfaces. This includes areas that are subject to occasional chemical attack provoked by hydrocarbons. It is also recommended for flexible bonds between similar and different materials most commonly used in the building industry for both internal and external applications and as a replacement or to integrate mechanical fasteners.

Examples If Used As A Sealant:

  • Sealing expansion and distribution joints subject to movements up to 20% of the average width of the joint in industrial floors subject to vehicular traffic, including heavy vehicles, concrete floors for internal and external car-parks, supermarkets, shopping centres and warehouses, ceramic flooring and coatings.
  • Areas subject to intense traffic such as supermarkets and industrial environments where fork-lifts are in use, concrete walls and general internal and external vertical structures where the use of a thixotropic product is required such as old concrete floors which are to be covered with a Mapefloor System.
  • Sealing cracks
  • Sealing pipe-work systems for air-conditioning and electric cables
  • Sealing sheet-steel sections, such as flashing and guttering
  • Sealing general fillet joints.

Examples If Used As An Adhesive At Thickness's Up To 3 mm:

The high bonding characteristics and rapid-hardening properties of Mapeflex PU45 make it suitable for joining various materials and for bonding on a wide range of
substrate materials. Mapeflex PU45 may be used to bond most building materials, for example cement and cement-based products, cellular concrete, bricks, steel, copper, aluminium, general pre-painted surfaces, glass, mirrors, gypsum, wood and wood-based materials, ceramics, clinker, insulating material, plastics such as PVC, acrylic glass and fibreglass.

If Mapeflex PU45 is used to form flexible bonds, it is a multi-purpose product for constructing and finishing building works such as:

  • Tin work and flashing
  • Skirting boards, cable beads, beading rods and corner guards
  • Pre-formed decorative elements
  • Bathroom fittings
  • Window sills
  • Roofing tiles, concave roofing tiles, covering panels and insulation panels


Mapei Mapeflex PU45 hardens following its reaction with atmospheric humidity and its special characteristics offers a guarantee of long service life. It may be used on both horizontal and vertical surfaces. To avoid the sealant spreading out of the joint, and to leave an attractive finish, we recommend using masking tape along the edges of the joints, which must be removed immediately after smoothing off the sealant. Mapeflex PU45 bonds well even without the use of a primer on substrates which are solid, free of dust and perfectly clean and dry. We recommend applying Mapei Primer M if the absorbent surfaces are not solid enough, if they have a slightly powdery surface or if the joints are subject to high mechanical stress or frequent, prolonged contact with liquids. We also recommend applying Primer M on cementitious surfaces which are still fresh.

When applied on non-absorbent surfaces such as iron, steel, aluminium, copper, ceramic, klinker, glass and zinc-plated sheet, Mapeflex MS45 forms a good bond if the surface is cleaned with a suitable degreasing product. Applying Primer M on the surface will improve adhesion over the years. When applying on plastics, it may help to roughen the surface by using fine sandpaper and then to apply a coat of Mapei Primer P one-component primer in solvent.


IMPORTANT NOTICE: From 24th August 2023, adequate training is required before industrial or professional use of this product. Training can be accessed at:

Technical Details


  • Available in Boxes of 12 x 300ml cartridges

Technical Info

Components: Single Pack
Type: Solvent-free,
Finish: -
Stock Colours: Black and Grey
Tintable: No
VOC Content: -
Volume Solids: -
Suitable Substrates: Concrete, ceramic, guttering
Application Method: Tube in extrusion gun
Theoretical Coverage: -
Density (g/cm³): 1.42 ± 0.07
Dry solids content (%): 100
Recommended application temperature range:: from +5°C to +35°C
Dust Dry: 90 mins
Final setting after: 24 h (per 3 mm of thickness) - 48 h (per 4 mm of thickness)
Set to light foot traffic: According to the depth of the joint
Shelf Life: Store in a cool dry place for up to 12 months

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