Air Tightness Tapes & Membranes

Here at bio space, airtightness tapes and insulation membranes are specified to support a consistent, high performing building envelope across walls, roofs and floors. Used across both new build and retrofit projects, these systems are selected to suit different substrates and build types, helping ensure reliable results on site where detailing matters most. For larger projects, bulk supply options are available, making it easier to maintain consistency across full installs without delays. These products are often used alongside natural insulation systems and compatible lime-based renders, supporting breathable build-ups where moisture control and long term durability are critical.

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Frequently asked questions
What performance standards do airtightness membranes need to meet?

Most insulation membranes and airtightness systems are tested against standards such as BS EN 12114 (air permeability) and BS EN 13859 (flexible sheets for waterproofing). These ensure the material performs under real conditions, including wind pressure and moisture exposure. Always check certification data to confirm suitability for your specific build-up.
What are airtightness tapes used for in construction?

Airtightness tapes are designed to seal joints, overlaps and penetrations in membranes and building materials. They prevent unwanted air leakage, which is a key cause of heat loss and reduced energy efficiency. When applied correctly, they help create a continuous airtight layer across the building envelope.
What happens if airtightness detailing is poor?

Gaps or poorly sealed junctions allow uncontrolled air movement, which can bypass insulation and reduce thermal performance. Over time, this can lead to cold spots, condensation and potential mould growth. Even small failures at junctions can have a significant impact on overall performance.
Can these systems be used in retrofit projects?

Airtightness tapes and membranes are commonly used in retrofit applications, particularly when upgrading insulation or improving thermal performance. They can be applied internally or externally depending on the build-up. Careful detailing is required to integrate with existing structures and materials.
Where are airtightness tapes and membranes typically used?

They are commonly used in roofs, external walls and floors, particularly around windows, doors and service penetrations. These are the areas most prone to air leakage if not properly detailed. Correct installation in these zones is critical to achieving overall airtightness.