Ecological Building Systems

You are shopping in

The “GB” region can deliver orders to England, Scotland and Wales. For Northern Ireland deliveries, please choose the “Ireland” region.

Your region is: Great Britain Not right?
Sealing at joist ends with Visconn Fibre Black
Sealing cracks and gaps in block wall with Visconn Fibre Black
Spray application of Visconn Fibre (600ml Foil Cartridge) with Pro Clima Aerofixx Applicator Gun (sold seperately)

Pro Clima Aerosana Visconn Fibre

Select option:
  • Product Overview
  • Technical Details
  • Installation guide

Main purpose

Fibre reinforced liquid airtight sealant for sealing where the gaps, at critical junctions or between building components, are upto 20mm wide.

Use it on

Brickwork, blockwork, concrete, timber, wood based panels (including wood-wool boards), sheathing and cement particle boards.


Aerosana Visconn Fibre is a flexible liquid-applied fibre-reinforced air barrier for use as a gap filling sealant. The 5 litre buckets and foil cartridges can be brush applied and the 600ml foil cartridges can be spray applied when used with Pro Clima Aerofixx spray applicator gun. Visconn Fibre is suitable for sealing gaps of up to 20mm in width to form an elastic robust vapour retarding seal.

Where to use it

Aerosana Visconn Fibre liquid membrane can be used at critical junctions such as: wall to ceiling, wall to floor as well as connection between building components. It can be used when the gaps are up to 20mm in width.  Perfect for where gaps are too wide be sealed with Aerosana Visconn; which is only suitable for gaps of up to 3mm.

Commonly used on masonry brick and block builds to fill gaps, cracks or missing areas of mortar joints and at junctions to window and door reveals.

The 600ml foil cartridges are specifically for use with Pro Clima Aerofixx Applicator Gun.  Although the cartridge will fit in a typical 600ml extrusion gun, the consistency is unsuitable for this type of applicator and its nozzle. We would recommend brush application of Aerosana Visconn Fibre if you are using 600ml cartridges without an Aerofixx Applicator Gun.

What it does

Visconn Fibre offers a robust long-term flexible seal that can be paint applied to fill gaps of up to 20mm in width. It is an easy-to-use, quick and cost effective alternative to taping, and can be combined with the complete range of Pro Clima airtight tapes and grommets (once it has fully dried).

Visconn Fibre is applied by brush in a thick fibrous coating.  Visconn Fibre (Black) has a blue colour when wet and turns black once dried.  The white version is the same colour wet or dry.  Both form a flexible airtight seal which fills gaps of up to 20mm in width.  

Having a UV weather resistance of up to 3 months exposure, Visconn Fibre can be used in external sheltered areas.  Visconn Fibre (White) can be used when the sealed area will remain visible and/or needs to blend in with other lightly coloured painted surfaces.  Also useful in situations where light colours are a health and safety requirement (e.g. in a lift shaft).

How it works

The thick fibre- reinforced liquid of Visconn Fibre works by filling gaps and cracks and eliminates any unwanted air leakage. It is an ideal solution for common tolerance gaps around windows and doors rather than using expanding foam sealants. It creates a long-term flexible seal on the airtight connections of various substrates.

The 600ml foil cartridges of Visconn Fibre can be loaded into Pro Clima's Aerofixx Applicator Gun. This applicator gun uses compressed air to spray apply Visconn Fibre or apply it as a bead.

Why we love it

Aerosana Visconn is an excellent versatile connection sealant, available in two colours, that can be used in a variety of junctions and hard to access areas or where application of tapes membranes or other sealants would prove too cumbersome.  Application is easy by brush or by spraying with the Pro Clima's Aerofixx Applicator Gun.

System warranty

Pro Clima provide a limited system warranty, backed-up with public liability insurance, for all airtightness system, roof and wall sealing system and construction products that they supply. A 10-year warranty is provided for these products when correctly installed in combination with approved thermal insulation materials and other Pro Clima system products. When correctly installed in combination with other manufacturers’ products (not made by Pro Clima), a 6-year warranty is provided.


  • Flexible and airtight
  • Can be plastered over
  • Perfect for retrofit
  • Simple DIY solution
  • Humidity variable
  • Quick and easy to apply
  • Available in black or white


  • Once dried, offers significant safety against potential air leakage due to movement of building components
  • It creates a much more effective and suitable seal where expanding foams or brittle silicone sealants could potentially be used ineffectively
  • Can be easily integrated into traditional wet plastered systems for a robust airtightness solution at connection areas
  • Use to ensure airtightness at difficult or awkwardly shaped junctions around timber joists or wall plates
  • Is ideal for novice airtightness applicators to ensure full airtight seals at tricky junctions
  • Is vapour open to allow the transport of moisture at critical junctions to help offset condensation risk
  • ISO 16000 hazardous substance compliant
  • Internal and external use, ready-to-use brush-on sealant


There are currently no questions and answers published for this product

Ask A Question

Technical Details

Key Technical Data

Technical Datasheet

Installation Guide

How to Install

The condition of the substrate needs to be reviewed prior to the application of the Visconn Fibre. Some areas of gaps and larger cracks may require additional coats during application. If the substrate is rough or friable and unstable in any way, this area needs to be made good.  

All surfaces should be clean, dry and any flaky unstable material brushed off and wiped clean or cleaned using compressed air. Visconn Fibre should not be applied in areas where water repellent grease or silicones have been applied. Application to frozen surfaces is not possible, use only in temperatures of above 5 degree Celsius.

Ensure the product is thoroughly stirred before use.

Once Visconn Fibre has been applied and allowed to dry; it can be integrated into plaster or standard Aerosana Visconn to ensure a continuous, fully airtight, robust and flexible long term airtight solution around these openings.

A gap in blockwork being measured to see if Visconn Fibre is suitable for application
A gap in blockwork suitable for use with Visconn Fibre (up to 20mm)
Visconn Fibre after being stirred and ready for painting
Visconn Fibre after being stirred and ready for painting
The gap in the blockwork being painted over with Visconn Fibre
The gap in the blockwork being painted over with Visconn Fibre

Hints and Tips

When filling gaps, guide the brush flat across the crack so that the gap becomes completely filled.  

It can be used as alternative to Contega Solido SL tape to seal around window and door frames, as it seals gaps of up to 20mm, a common width between window/doors and the surrounding masonry reveals.

Find a stockist Find an installer