Membranes and sealing
Insulation only works when it is airtight. We lay membranes with overlaps and seal every joint and penetration.
Facts
- vapour control on the warm side
- Inside
- wind membrane on the cold side
- Outside
- overlap between strips
- ≥ 100 mm
- ready for the airtightness test
- n50
A vapour control membrane on the inside keeps room moisture out of the insulation. A wind membrane on the outside protects the wool from wind and rain while letting vapour out.
The weak points are not the membrane itself but its edges: seams, joints to walls and windows, pipes and cables. We seal them with dedicated tapes and grommets so the building passes its airtightness test.
What we seal
- Vapour control in roofs and ceilings
- Wind membranes on walls and roofs
- Membrane seams and overlaps
- Pipe, cable and duct penetrations
- Junctions with walls and windows
How we work
We lay
We fix the membrane evenly and overlap strips by at least 100 mm.
We seal
Seams get tape; penetrations get grommets.
We check
We inspect every junction before the finishes go on.
Questions
What does a vapour control membrane do?
It stops moisture from warm rooms reaching the insulation. Damp wool loses its performance, and mould can form in the structure.
What is an airtightness test?
A fan creates a pressure difference across the building and measures how much air leaks through. In Lithuania it is required for new A+ and A++ class buildings, so the sealing has to be thorough.
Other services
Request a quote
Tell us what you want insulated and where. We will reply with a price.