Electrical airtightness

MackDeToaster

Doing a self-build and am wondering the best way to ensure airtightness on electrical wiring/sheathing ? I don't want air drawing out (or blowing in) from sockets. Electrician doesn't know the best way to solve. I'm thinking fire-rated silicone inside the top of any sheathing in the attic space, and possibly the same where sheathing enters the boxes, or would this be safe ? I've already used air-tight paint on the chasings etc.

listermint

Silicone sounds good. Could also use rubber gaskets into the conduit in attic I wouldn't believe you have to go overboard with top and bottom.

sydthebeat

Create a service cavity between the membrane and the ceiling, so that your not puncturing the membrane with your electric first fix

Calahonda52

You need to check if the silicone will not attack the PVC on the wires.
I dont below it needs to be fire rated.
unless there its plenty slack at the bottom, u may only be able to seal the top

keno-daytrader

Silicon will shrink over time and is a waste of time for airtightness details.

If you dont have a service void and are beyond 1st fix use Orcon f or Acrabond around the conduits. Its what you would use to seal airtight membranes to block walls. Then airtight tape sealing where the wire exits the conduit in the attic.


I would definitely pay close attention to this part of the airtightness, the conduits can be a huge source of air infiltration from a cold attic space to the living space.

MackDeToaster

Many thanks for the advice. I'm going with an airtightness adhesive squirted into the conduits/sheathing, then airtightness tape, and a final dollop or airtight-paint on that !