Paint-on airtight membrane and vapour control

Blowerproof Liquid Brush

blowerproof engels


  • Paint-on airtight membrane, applied with flat paintbrush.
  • Suitable for DIY.
  • Certified for the permanent airtightness of building connections: floor/wall, wall/wall and wall/ceiling connections, pipe penetrations and window jambs, (curtain) walls, wall/roof connections (steel deck).
  • Suitable substrates include concrete, masonry, bricks, blocks, plaster/render, engineered wooden boards, tapes, membranes, aluminium, steel and PVC.
  • Consumption: 0,5 to 0,8kg/m².
  • Certificates: M1, Exova, Passive HouseBBA, BBRI.

Main advantages

  • The only product of its kind which is certified Passive House.
  • Just 1 product needed for all building connections in a house or construction.
  • Also applicable on humid(moist) surfaces.
  • Expected lifetime of Blowerproof is "the same as the element it is applied on", (ref. BBA certificate), which is an advantage compared to airtight tapes.

Application guide (website Passive House)

Productsheet (PDF)


Belgium (Hevadex - manufacturer)


Spinnerslaan 6

9160 Lokeren


tel: 003293483100

United Kingdom

Ecomerchant Ltd

Approved applicators: kindly contact Ecomerchant Ltd.


Blowerproof Ireland Ltd

Approved applicators: kindly ask the importer

Other countries

We have specialist importers and distributors accross Europe: Spain, France, Finland, Denmark, Roumania, ... 

For contactdetails, email to 

We are looking for (exclusive) distributors in Canada, USA, China and Australia.

APPLICATION: airtightness floor to wall junction

Airtightness floor to wall junction with Blowerproof - brushapplied

  • Apply BLOWERPROOF® LIQUID BRUSH with a flat synthetic bristle paintbrush. Consumption: 0.5kg/m² to 1kg m² or about 500 to 1000 microns. 
  • BLOWERPROOF® LIQUID BRUSH is not painted but smeared, as to obtain a closed membrane over a surface . So scoop with the flat paintbrush, and smear over the surface. 
  • Thickness is verified with a wet film thickness gauge for each layer, to ensure minimum total coverage of 500 microns. In general, when the substrate is not visible anymore, the coverage of min. 500 micron is reached. Avoid (local) layer thickness of > 1500 micron for example in joints/openings in the surface which haven’t been prepared properly. 
  • Apply over an area sufficient to overlap finish plaster or render by 50mm and in all cases a minimum of 50mm above DPC at ground level. 
  • During the drying process, BLOWERPROOF® LIQUID BRUSH will change colour from blue to black. Black colour means that BLOWERPROOF® LIQUID has dried out and is ready to accept specified finish.

APPLICATION: airtightness pipe penetrations

Airtight sealing of pipe penetrations with Blowerproof

blowerproof engels
  • Fill gaps greater than 2mm with non-shrink gap filling mortar or non-shrink airtight polyurethane foam.
  • Apply BLOWERPROOF LIQUID BRUSH, the thixotropic version of BLOWERPROOF LIQUID, with a suitable paintbrush in two coats ensuring that the first coat is fully dry before applying the second coat.
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