Airtightness progress, this is a lot of work...

[Post and beam]

A couple of pictures of my efforts on the upper floor so far. I have so many of these aiirtight box's to make, so so many.

 

 

[benben5555]

What is the purpose of the airtight box?

[Nickfromwales]

2 hours ago, benben5555 said:

What is the purpose of the airtight box?

Light fitting (recessed) methinks, due to the cable?

[Nickfromwales]

Nice neat work @Post and beam, "never let the b*stards grind you down" lol, it'll be worth it in the end.

 

Airtightness is 'where it's at'  

[Post and beam]

16 hours ago, benben5555 said:

What is the purpose of the airtight box?

Yes as Nick says, recessed lighting. also for the MVHR ducts.

The intello airtight membrane is fitted to the underside of the first floor ceiling. Once the plasterboard goes up, each penetration of it for the lights and ducts breaches the airtight boundary. So the boundary has to be extended to include these fittings. 6 MVHR outlets and 7 recessed light fittings in the wetrooms.

Now i know why the TF company left a pallet of Noggins for me.

13 hours ago, Nickfromwales said:

Nice neat work

Thanks Nick. some are better than others. The long runs of the Intello sometimes run more true that others. That is difficult to do on your own. Love my Dewalt stapler though

[ProDave]

This is why my advice at design stage is build a house with a warm roof and all insulation and air tightness following the roof line.

 

Lovely warm loft and no bother with lots and lots of detailed air tightness at the junction between a warm room ceiling and a cold loft above it.

[Andehh]

It's worth it in the end!! Don't cut corners, quality over quantity and a life time to enjoy it.

[Barny]

I have an airtight test booked for Monday. I need to block up the MVHR vent / sink drain for the test. Can anyone recommend a suitable tape/cover? Obviously not using Siga which I used for airtightness as I won’t get it off after the test. Thanks

[Russell griffiths]

Gaffa tape, don’t overthink this, it’s a hole, block it up, carrier bag and some tape, job done. 

[Thorfun]

On 11/03/2025 at 06:44, ProDave said:

This is why my advice at design stage is build a house with a warm roof and all insulation and air tightness following the roof line.

 

Lovely warm loft and no bother with lots and lots of detailed air tightness at the junction between a warm room ceiling and a cold loft above it.

+1 to this! In fact if I were to ever do it again I would swap our attic trusses for a cut roof. The attic trusses were a pain to membrane around.