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Mapei Mapeflex PU45 300ml- Box of 12

£109.01 (£130.81 Inc. VAT)

Single Component Rapid Hardening, Paintable, Thixotropic Polyurethane Sealant and Adhesive With a High Modulus of Elasticity.

  • Easy to apply
  • High bonding characteristics
  • Rapid-hardening
  • Solvent-free
  • Odourless
  • Low impact on the environment
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Mapei Mapeflex PU45 – One component polyurethane sealant

Mapei Mapeflex PU45 – One component polyurethane sealant. Rapid-hardening, paintable, thixotropic polyurethane sealant and adhesive with a high modulus of elasticity. Mapeflex PU45 is a one component, thixotropic, easyto-apply polyurethane-based sealant and adhesive with a high modulus of elasticity, made according to a formula developed in MAPEI’s own R&D laboratories and meets the requirements of ISO 11600 class F20 HM. Solvent-free, odourless with a low impact on the environment, Mapeflex PU45 is certified as EC1 R as a product with very low emission of volatile organic compounds.

Mapeflex PU45 complies with Euronorm EN 15651-1 (“Sealants for façade elements”) with performance rating F-EXT-INT CC and EN 15651-4 (“Sealants for pedestrian walkways”) with performance rating PW-EXT-INT-CC.

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. The product is ready to use and is available in both metal cartridges and soft cartridges equipped with a special extrusion gun, which makes the product particularly easy to use. The consistency of the product is ideal for quick application and its rapid-hardening characteristics (approx. 3 mm every 24 hours) allows the surface to be put into service quickly with resulting economic advantages. We recommend using elastomeric paint such as Elastocolor Paint after treating the surface of the sealant with Colorite Performance. Always carry out preliminary tests to make sure the sealant and paint are compatible.


Mapeflex PU45 has been specially developed for sealing expansion and distribution joints in horizontal and vertical surfaces, including those which 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.

Recommendations for using Mapei Mapeflex PU45 – One component polyurethane sealant

  • Do not use on dusty or flaky surfaces.
  • Do not use on damp surfaces.
  • Do not use to seal joints in stone and marble: use Mapesil LM.
  • Do not use on surfaces which are dirty with oil, grease or mould-stripping compounds, as the bonding could be compromised.
  • Do not use on bituminous surfaces where the bleeding of oil may be present.
  • Do not apply Mapeflex PU45 if the temperature is below +5°C.
  • Do not contaminate the surface of the product with alcohol while still wet to prevent affecting its correct polymerisation

Application examples of Mapei Mapeflex PU45 – One component polyurethane 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, including in 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
  • 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
  • Used as an adhesive at thicknesses 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:

  • tinwork 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


Not quite what you’re looking for? Click here to browse more of our Mapei range.

Want to see how Mapeflex PU45 and other Mapei products have been used? Click here to view a range of Mapei Projects.

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Screed Giant offer great service, their products are good value for money and they always deliver on time. Louise is always on hand to help when we need something - so an all-round great company! Vale Garden Houses
100% of our clients asked would recommend us!
I was very impressed with Ellie's approach to a potential sale. She checked on availability - called me back promptly and handled the order efficiently. I would most definitely call again and order more products given this level of service. NAS Corporation Ltd.
100% rated our customer service experience very positive!
The experience is always positive. The girls on the phone always go out of their way to make sure the orders are processed quickly and delivered on time. S J Whelan Ltd.
100% of all clients asked, who were phoning to place an order, rated our customer service experience very positive!
I have dealt with Georgia on several occasions and her service has been very professional and efficient - makes my job a lot easier - many thanks. Richardsons
100% of all clients wanting technical advice agreed they would call again for more technical assistance!
Extremely likely to recommend Screed Giant to a friend or colleague.

JJ McCarthy Interior Design

Very happy!

J.W.Cannon & Co Ltd.

Ellie was very professional and helpful, and helped us with a small discount.

Ecofit Energy Systems

Very helpful. Confirmation of order being dispatched. Emails were swift.

PED Technologies Ltd.

I found Georgia to be really helpful and went out of her way to get your product shipped to us as soon as possible. We will certainly use Screed Giant again. Many thanks.

Tim Sadler Associates

Ellie was very helpful and pushed through my order for next day delivery.


Very helpful and the delivery service was very quick. Thank you.

TEC Construction

Very good, even though i was only placing a small order staff couldn't have been more helpful.

R. Soper

Very easy, we put in an order also asking for delivery dates and time, always accurate and found deliveries on time.


Ellie was personable and efficient. Excellent customer service.


Very professional from initial contact through to completion. All answers were provided instantly or by return of call - no question was ignored, trivialised or forgotten. I was kept fully aware of stocks, costs, availability, deliveries and problems. Because of the nature of the works we were completing, quantities and orders were all last minute and ll on credit card payments- no problems at all to Screed Giant. Always, a very pleasurable experience. Very many thanks.

Richard Morris Constructions Ltd

Good, Ellie was very helpful and more importantly did what she said she was going to do!

DEP Construction Services Ltd

Georgia went above and beyond- I required a half pallet of poziment specialist lightweight screed; she managed to secure said half-pallet for me, saving me a few hundred quid! Her phone manner is brilliant and she made sure I was kept up-to-date with what was happening with my order. I'll definitely be recommending you to all of my builder contacts and will be using you again. Many, many thanks.

Markendale Electrical Services.

Spot on!

Graeme Harding Flooring

Very good service, quick delivery and great customer service from Georgia.

Sean- SR Plastering

Great product, easy to use, now I can tile next week. Thanks for the prompt delivery.

Mark Bailey

Georgia was very helpful. She created a quote, placed and handled our order. She even got a quick turn around on next day delivery before 12:00. I was very impressed with her excellent customer service.

Cavendish Bespoke

I called up with an enquiry about a product, really unsure as to what I needed. Georgia was incredibly helpful with finding a solution for me and liaising with your technical team. Her service could not have been better.

Union Tavern

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5* - Couldn't fault the company.


Very helpful staff with good product knowledge. Problem with the courier company, order was only part delivered (not Screed Giant's fault). Screed Giant's staff dispatched missing products overnight to me. This was necessary as we had trades booked in to start work and needed materials on site. All done extremely efficiently, will certainly use again. Many thanks.

313 Projects Ltd

5* - Very competitive prices, quick and reliable service. I would highly recommend this company and will use again!

JEV Tiling

I ordered some specialist product from the website, however conscious that I was under a tight deadline I rang customer service at Screed Giant and was greeted by a very friendly, helpful lady called Georgia who was able to expedite my order which duly arrived early the next day. I would thus have no hesitation in recommending Screed Giant.


5* - Incredibly helpful I spoke with Georgia regarding my order. She was very helpful and went out of her way to meet my requirements. I would definitely use them again.

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Georgia kindly made a number of enquiries on my behalf RE the product I was sourcing. Georgia was knowledgeable RE products. Her verbal and written communication was extremely polite and helpful. In my opinion, her level of customer support and care was exemplary.


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Very good. Always great ordering through email and phone. Prompt delivery.

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Extremely likely to recommend. I contacted Screed Giant using the chat facility on the website. Ellie responded, she was quick, informative and very helpful and then sent me a transcript of the discussion for reference. I later spoke to Ellie on the phone as I needed very quick delivery and once again she was very efficient and very helpful.

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Extremely likely to recommend. Order was dealt with quickly and efficiently.

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Excellent customer service


Fast response on quote request, clear website, friendly and helpful staff. Nice to deal with a company and people that has similar ethos to us. Keep it up, and good luck for the future.

Materials arrived around 11.00am today, and whole floor completed by 14.30!! Exactly the right amount and looks brilliant!! Many, many thanks for your assistance and your patience!!


Very good and very helpful

Andy was not only super knowledgeable and helpful. He also has the rare skill of being able to communicate his knowledge to a novice in way that I could both understand and address the problem. Thanks again.


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Iron Hill Construction

Thanks Screed Giant. Good service and assistance through the order. Appreciated.

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Individual Floor Fitting

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