Airtightness membrane for cold loft

[DeanAlan]

We're renovating a 1930s semi (as well as a large SIPs extension) and having to move back in before fully completed.

 

We're soon to build the stud walls on the first floor up to the original roof timbers. Ultimately we expect to use something like passive purple liquid membrane to provide the airtight for walls. I believe we need to put an airtight membrane above the replacement plasterboard for the first floor ceiling and have the liquid membrane connect/lap with the airtight membrane of the ceiling/loft at the ceiling/wall junction.

 

What is the detail for stud walls connecting up to the roof joists? We need to get enough membrane in there, on top of the stud walls, so that we can then put the rest of the membrane in (lapped and taped) before we put the plasterboard in.

 

I assume the membrane needs to go over the stud wall top, under the roof joists.

 

Let me know where I'm going wrong here please? What products would you recommend? How does the stud wall connect to the roof joist with fixings that penetrate the membrane?

 

cheers,

-Dean

[nod]

8 hours ago, DeanAlan said:

We're renovating a 1930s semi (as well as a large SIPs extension) and having to move back in before fully completed.

 

We're soon to build the stud walls on the first floor up to the original roof timbers. Ultimately we expect to use something like passive purple liquid membrane to provide the airtight for walls. I believe we need to put an airtight membrane above the replacement plasterboard for the first floor ceiling and have the liquid membrane connect/lap with the airtight membrane of the ceiling/loft at the ceiling/wall junction.

 

What is the detail for stud walls connecting up to the roof joists? We need to get enough membrane in there, on top of the stud walls, so that we can then put the rest of the membrane in (lapped and taped) before we put the plasterboard in.

 

I assume the membrane needs to go over the stud wall top, under the roof joists.

 

Let me know where I'm going wrong here please? What products would you recommend? How does the stud wall connect to the roof joist with fixings that penetrate the membrane?

 

cheers,

-Dean

ideally you need to fit the membrane before the studs 

Run a line of acoustic sealant along the wall perimeter Then shot fire a 25x25 metal angle over the membrane and acoustic sealer 

As pictured