Blowerproof Liquid 'Spray' - A Spray Applied Airtight Sealing Membrane (Spray installation service) P.O.A

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BLOWERPROOF LIQUID is a voc free polymer based liquid, that is applied with an airless paint spray device and dries to an airtight flexible coating with a good adhesion on different surfaces such as concrete, brick, wood, metal etc it forms a permanent, flexible continuous airtight seal on both new build and retrofit.

Ecomerchant Blowerproof spray airtightness membrane

The water based polymer is spray applied to create an uninterrupted air and vapour -tight seal on a wide range of surfaces, and for floor / wall connections, wall / ceiling joints, and roof connections

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. 

Blowerproof turns from blue to black as it cures so you can be sure the seal is complete when it turns black.

Available as blue/black for general applications or white if for use under plaster (doesn't show through) or for round windows and doors


  • Walls
  • Ceilings
  • Use on concrete / masonry / brick / timber / metal etc 


  • Service penetrations, pipes, cable, ducting etc
  • Floor to wall junctions
  • Ceiling to wall junctions
  • Steel decks
  • Blockwork
  • Masonry
  • Brick

Can be overpainted, plastered or rendered.

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

Also available as Blowerproof Liquid Brush, used for primary sealing of jambs, pipes and intricate or hard to get to places

Blowerproof Liquid Spray requires application with a manufacturer recomended spray device or by qualified and approved applicators, speak to us about pricing,  application or training

Ecomerchant Blowerproof BBA


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Blowerproof Liquid Spray is a voc free polymer based liquid, that is applied with an airless paint spray device and dries to a permanent, flexible airtight coating with excellent adhesion to different surfaces including concrete, brick, masonry, wood, metal etc

Ecomerchant Blowerproof liquid brush

Liquid Proof Blower Spray 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 Spray is an ideal product for materials with different coefficients of expansion
  • Extensively tested for adhesion and elasticity

Material: waterborne polymer 

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)

Diffusion resistance number: 76 854 μ

Storage time : 1 year ( in unopened packaging )

Storage temperature : between 5⁰C and 20⁰C

* Adhesion Reports available on request

Ecomerchant Blowerproof liquid Brush

Generals application guidance

  • Remove dust and loose particles; remove surface contaminants which may affect adhesion. Treat blemishes; fill holes and cracks ≥3 mm
  • Do not apply when (surface) temperature < 5 ° C
  • Blowerproof Liquid Spray is ready for use, do not dilute with water or solvents; briefly mix with hand mixer
  • Use an airless paint spray device - please contact us for full equipment specification
  • Apply thick enough to ensure air-tightness (0.6mm recommended); indicative consumption up to 1.0 kg / m²
  • Avoid during the drying phase contact with any kind of water, other liquids or construction chemicals
  • Cleaning Material: immediately after use with water
  • At least 24 hours to 48 hours to dry before applying another material on the dried - black - finish. (During drying, the colour changes from blue to black).

Typical Applications

Pipes & Penetrations

Ecomerchant Blowerproof Liquid BrushNumerous energy test reports, performed at the end of a construction project, show that pipe penetrations are in many cases a cause for not obtaining the requested level of airtightness. 

For the airtight sealing of of pipe penetrations: first apply polyurethane foam around the pipe penetrations; after hardening, remove the excessive PUR foam, and apply 2 layers of Blowerproof Liquid Spray; in all cases, apply a sufficient, well covering layer to guarantee airtightness.


Floor to Wall

Ecomerchant Blowerproof Liquid BrushIn order to obtain a sufficient airtightness of a building, it is important to make the floor/wall connections on the inside of a building airtight. 

For floor/wall connections, both spray and brush applied products can be used.

Blowerproof Liquid is an airtight coating which is sprayed with an airless spray device on these floor/wall connections. The substrate must be dust free, solid and free from large cracks or gaps before starting the application. Holes and joints need to be plugged beforehand: large holes and joints (> 5mm) can be repaired with a fast setting cement based product or polyurethane foam, small holes and joints (2-5mm) can be sealed with Blowerproof Liquid Brush.

For larger projects Blowerproof Liquid can be sprayed with an airless paint spray device; this fast application method allows applying up to 300 linear meters per day. See more  by clicking on the 'More Info' tab above

For smaller projects, such as private houses, Blowerproof Liquid Brush can be used with a flat paintbrush, suitable for water based products. Apply in two coats; second coat must only be applied when the first coat is completely black.

Wall to Ceiling

Ecomerchant Blowerproof Liquid BrushThe wall/ceiling connections also need to be made airtight, this can be problematic when the surfaces are of two different types of material such as red brick/concrete or steel/concrete. Different construction materials react differently to changes in humidity and temperature, which can lead to small cracks in plaster or another type of finishing, and so creating air leaks. 

For wall/ceiling connections, both spray and brush applied products can be used. 

Blowerproof Liquid sprayed with an airless paint spray device (1 layer) or Blowerproof Liquid Brush which is applied with a paintbrush in two layers. Apply in two coats; second coat must only be applied when the first coat is completely black.


  • WTCB test reports available, incl. ageing:
  • Damp diffusion resistance factor 
  • Adhesion tests on Aerated concrete blocks, red brick and concrete brick; dry and humid substrates
  • Adhesion tests on OSB and MULTIPLEX; PVC, aluminium, metal, EPDM
  • Adhesion tests of plaster on Blowerproof Liquid coating
  • Elongation at fracture: 250 @ 350%
  • Elongation/tensile strength 120% elongation;  42 N/50mm tensile strength


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