Best Seller

Blowerproof Liquid - A Roll-On/Spray-On Airtight Sealing Membrane 10kg

Blowerproof Liquid - A Roll-On/Spray-On Airtight Sealing Membrane 10kg

Write a review

Specification Clause Downloads


Test Category

No Downloadable

No Specification

full view icon

Blowerproof Liquid Roller/Spray is a VOC free, water based, flexible, polymer providing a unique and sustainable solution for the production of airtight buildings in both new build and retrofit.

Ecomerchant Blowerproof Liquid Brush

The water based polymer is roller/spray applied to create an uninterrupted air and vapour -tight seal.

Blowerproof liquid creates a seamless, continuous air and vapour -tight seal over cracks and gaps. Because the seal perfectly follows the contours of the substrate and in combination with the high flexibility and superior adhesion, the connections remain airtight over the long term. Blowerproof liquid is the fast, flexible and durable solution for all airtight connections.


Ideal for sealing

  • walls
  • ceilings
  • larger areas


Blowerproof Liquid Roller/Spray comes in a re-sealable 10kg tub. Allow up to 1kg per square metre on highly porous surfaces for smooth non porous surfaces allow 750grams per square metre. 

One 10kg tub will cover approximately 10m2 

Price is per tub

Ecomerchant Blowerproof BBA Logo

full view icon

 Blowerproof Liquid is a rapid and secure way to create a permanent and continuos airtight layer on a wide range of substrates.

Applied directly to the surface with no need for primers, Blowerproof Liquid is perfect for sealing blockwork, masonry and concrete, its simplicity of application helps eliminate applicator error. Penertrations and connections can be sealed prior to roller/spray application by 'cutting in' with Blowerproof Liquid Brush, larger gaps and holes can be plugged with Blowerproof Non Shrink Gap Filling Mortar to ensure a permananet and felxible airtight layer.

Blowerproof Liquid Benefits

  • Versatile for use on a wide variety of building materials like concrete, stone, wood, metal, aluminium,  insulation , EPDM, etc. *
  • Suitable for new buildings and renovation
  • Seamless and secure even with difficult connections
  • Quick and easy application
  • Moist surfaces are no problem
  • Can be over plastered, rendered or painted
  • Fully water-borne
  • Blowerproof Liquid is ideal  for materials of different coefficients of expansion
  • Extensively tested for adhesion and elasticity

Material: waterborne polymer paste 

Colour: Blue colour changes to black as drying is completed

Consumption:  between 0.75 and 1.0 kg / m² (about 1.0 mm in thickness) dependednt on substrate porosity

Substrates: bricks, blocks, concrete, stone, wood, metal, aluminium,  insulation , EPDM, etc. *

Extensibility: 380 % (at 0.6 mm dry film thickness )

Crack bridging < 2 mm ( 0.6 mm dry film thickness ) Fill with Blowerproof non shrink gap filling mortar

Diffusion resistance number: 76 854 μ

Storage time : 1 year ( in unopened packaging )

Storage temperature : between 5⁰C and 20⁰C

* Adhesion Reports available on request

Product characteristics:

  • Ready to use
  • Water based; zero VOC*
  • Apply with long haired roller
  • Flexible, crack bridging**
  • High adhesion, also on humid surfaces
  • Available in blue and white

BBRI, Warrington fire, VOC and blower door test reports available on demand

Areas of use:

  • Concrete, masonry, brick & blockwork walls
  • Floor/wall connections
  • Wall/ceiling connections
  • Wall/wall connections
  • Window jambs
  • Penetrations
  • Vertical and horizontal joints


Ensure the substrate is free of dust, loose or flaking material, efflorescence and any other surface contaminants; fill holes and gaps greater than 5mm with BLOWERPROOF NON SHRINK GAP FILLING MORTAR or non-shrink polyurethane foam. Remove standing water.

Corners, penetrations, window jambs etc. can be sealed with BLOWERPROOF LIQUID applied with a suitable long haired brush, gaps up to 2mm may be covered with BLOWERPROOF LIQUID. Penetrations and connections with gaps between 2mm and 5mm can be pre-sealed with BLOWERPROOF LIQUID BRUSH (a fibre reinforced version) prior to applying BLOWERPROOF LIQUID to the substrate, apply directly over the pre-sealed areas. Seal all gaps over 5mm with BLOWERPROOF NON SHRINK GAP FILLING MORTAR


Before use mix with a handheld paddle mixer set at low speed; the ambient and substrate surface temperature must be > 5°C;

Apply BLOWERPROOF LIQUID only on the inside on the building. Apply in two layers:  total minimum consumption should be 0.5kg/m2. Apply using a long haired roller suitable for water based acrylic paints; apply the second layer after the first layer is dried – if using the blue version this is indicated by change in colour to black; thickness can be verified with a wet film thickness gauge; check visually to ensure complete coverage;

BLOWERPROOF LIQUID is independently tested and suitable for use on different types of brick, blockwork, concrete, wood, polyurethane foam, insulation, metal, pvc, aluminium. Indicative drying time is dependent on substrate temperature, air humidity, application thickness  and ventilation and can range from 30 minutes to 24 hours


Do not apply any type of finish on BLOWERPROOF LIQUID until it is completely dried; the blue BLOWERPROOF LIQUID will be black when completely dried. BLOWERPROOF LIQUID can be overpainted, it is recommended to try a small test area first. Where plaster or render is to be applied by hand or machine, use a suitable plaster primer as a bonding layer.


  • Wash down brushes and tools with clean water
  • Containers can be recycled please check local facilities
  • Brushes can be cleaned an re-used


  • Store full un-opened containers in a dry frost fee environment between 5°c and 35°c avoid direct sunlight or contact with a heat source
  • Seal part used containers by pushing down firmly in the centre of the lid when closing to expel air, ensure lid is closed tightly
  • Do not use product from damaged or broken containers
  • Seal open cartridge nozzles from air with cap or tape
  • Shelf life, product will keep for 12 months from date of manufacture if kept according to these instructions in unopened containers


Please refer to product MSDS information 

For more details please refer to the data sheet and application guide

    full view icon

    Blowerproof Liquid comes in three forms, the brush applied fibre reinforced paste as described in the previous pages, a slightly more liquid version for roller application called Blowerproof Liquid Roller and as a spray version which is only available via our application service

    We only sell the brush and roller versions online, the spray version is typically applied by a professional applicator.

    Blowerproof is a new product to the UK; throughout Europe the application of a spray airtightness membrane is a common way of achieving the high standards of airtightness enshrined in their building regulations so this product has a huge number of references and case studies including detailed post occupancy monitoring.

    If you have an application that might benefit from the speed and efficiency of Blowerproof liquid spray please get in touch by calling 01793 847 444

    A couple of questions?

    Q. What is the difference between the brush version and the liquid one?

    A.  The Brush version is reinforced with micro fibres the liquid version has no fibres and is slightly less viscous (thick)


    Q. Can I apply Blowerproof myself or do I need a professional?

    A. Blowerproof Brush (which comes in a variety of packaging and sizes) is designed for use by builders, self-builders and competent DIY’ers. The spray applied version requires a professional applicator


    Q. How do I apply Blowerproof?

    A. Follow the instructions in the application guide, basically it is a simple brush-on product similar to using a very thick paint. Use a synthetic bristle brush. For window surrounds, awkward or tricky places, penetrations and gaps locate using the cartridge version and then finish with a brush.


    Q. Why is Blowerproof described as blue/black?

    A. The colour of Blowerproof is a pale blue, when exposed to air the curing process turns it black, this menas you know when a full cure (seal) has been reached. When applying in two coats, for example on concrete blocks, apply the second coat when the first is black that way you avoid the chance of ‘brushing off’ the first coat but importantly its easy to see where you have already painted on the second coat – it will be blue.


    Q. Are there any other colours?

    A. Yes there is a white version specifically used where the topcoat will be plaster and a the black would show through.


    Q. Can I use Blowerproof to seal gaps ?

    A. Yes, especially by using the cartridge,  use a standard skeleton gun to locate a bead of Blowerproof in the gap, no more than 5mm deep, a second bead can be applied when it has cured.


    Q. Can I use Blowerproof to joint boards?

    A. Yes, apply as a bead and push the boards together, ensure a minimum of 2mm is left for the Blowerproof, clean down the board face with a scraper or spatula.


    Q. What can you put over the applied product?

    A. Pretty much anything from paint to plaster, render or dry lining


    Q. How do I know the product will work?

    A. Years of testing and use throughout Europe plus a full BBA certification mean absolute peace of mind


    Write Your Own Review

    You're reviewing: Blowerproof Liquid - A Roll-On/Spray-On Airtight Sealing Membrane 10kg

    How do you rate this product? *

      1 star 2 stars 3 stars 4 stars 5 stars

    Per Roll

    Availability: In stock

    * Required Fields


    You may also be interested in the following product(s)