What is airtightness membrane

Airtightness is the control of air leakage, i.e. the elimination of unwanted draughts through the fabric of the building envelope. This can be achieved using special membranes & tapes at the construction stage.

Why is it important

Only when the construction is airtight can warm air be retained within the building and cold air kept outside. This prevents unpleasant draughts and will mean greater comfort in the building along with lower heating costs. Airtightness also protects the building fabric against damage, helping to maintain its appearance and extending the buildings life.

• Decreases heat loss from draughts
• Lower Heating costs
• Eliminates damp & mould growth in the building fabric
• Essential for most controllable ventilation systems to run efficiently
• Healthier air quality

Intelligent membranes

Airtightness is not only about heat loss. It is also about the migration of moisture into the fabric of buildings, and potentially about loss of thermal performance and interstitial condensation

The best membranes will allow the building to ‘breath’ without affecting the airtightness. By breathability we are referring to the ability for moisture to be diffused back into the building. In summer months when there is high humidity, the membranes molecular structure will change to allow any moisture that has penetrated the wall from outside to escape inside. The is vital because otherwise the moisture will condense within the building fabric leading to mould growth

Process

Prior to slabbing & plastering, the membrane is installed along all timber surfaces and around window & door frames. The membrane is installed on the warm side of any ceiling insulation. The construction process continues with slabbing & plastering. It is vital that all trades are made aware of the membrane. Any penetrations such as wires or plumbing pipes must be prepared with tapes or grommets to ensure the air tightness is not compromised.