Passive house also requires that you have both the Outside membrane airtight to .6 as well as the inside layer however the final test to prove Passive house, is only required on the inside layer.
If you are heading toward a passive house, this article assumes you understand what vapour permeable membranes are. There are many brands of these membranes out there. If they are Passive House certified, they will all do a great job.
The 2 Big ones to look out for!
Staples – Staples can cause problems with overall air leakiness. 10’s of thousand’s of small holes add up to 1 big hole. Avoid using staples or use staples with thin pieces of packer or use double sided butyl tape on the studs and then brace the membrane into position using non structural battens, which you attach plaster board. We sell this tape, click on the link below…
- Foam a fill is not the best product to use for air tightness. If you want to use it, wait for it to dry, cut it back, and coat it with acrylic caulk.
- Use a glue for sticking the membrane down onto the floor, whether it be wood or insulated concrete. Some times its hard to ensure that the tape has stuck down sufficiently, especially when its quite dusty.
- Make sure you put pressure on the tape to dewater it
- When sticking onto wood or brick, use a butyl tape and an Acrylic Caulk (Not Polyurethane) where the bumps and odd shapes couldn’t be taken out by the tape.
- For retrofit, where there might be existing brickwork, the brick mortar needs to be sealed with a paint
- Caulk both ends of conduits, once your cables have been brought through, whether they are going inside to outside or inside to inside
- You can’t just use any type of tape, depending on the surfaces you are sticking to. Always refer to manufacturers recommendations.
Contact us for air tightness testing, and for a turn key solution for achieving the air tightness that you need at .6 ACH@50Pa, as long as you get us in, at the right time before plaster goes up. We are the most experienced company in Australia, helping our customers achieve passive house air tightness levels. We can save you a lot of money and time, to get the right advice at the right time. Call us for our references.