Airtightness tape

[Moggaman]

Hi. Just wondering about Siga Airtightness tape. I have a new block house with 110mm PIR board. I am using Siga Fentrim to airtight from the window frame across the insulation to the block. I have a roll of Siga Corvum also and I am using this to bridge across onto the cill. I am using Siga corvum cause it’s narrower and I don’t need to bridge across only 50mm of insulation. Is that ok?.

what is Siga corvum used for generally?

Also, do I need to fully cover the metal straps with tape ?

[Roundtuit]

Sorry, don't know anything about Siga tapes, but I think those straps definitely need covering if you want to avoid leaks, unless you're wet plastering.

Edited December 28, 2021 by Roundtuit

[dpmiller]

we used Corvum pre-split for our windows. Easy to use and sticks like sh*t to a blanket.

[Moggaman]

I am learning as I go… the walls are wet plastered but the reveals cannot be wet plastered I presume as it won’t bond to tape across the insulation… presume I will have to plaster board the reveal and then skim!??..but what about the part of the  reveal block behind the plasterboard that does not have tape on it ?.. is that an air issue?

[Declan52]

The tapes are like scrim cloth so a scratch coat will adhere to them.

[Moggaman]

23 hours ago, Declan52 said:

 

Edited December 30, 2021 by Moggaman

[Moggaman]

Now that I have completed the taping around windows I am looking at potential plastering issues!.. in some places the window straps sit out a little from the block/insulation so the tape whilst good , as it goes around the straps creates an air cavity in behind the tape.. will this create a plastering issue?

 

[KillyfadNewBuild]

On 30/12/2021 at 10:17, Moggaman said:

Now that I have completed the taping around windows I am looking at potential plastering issues!.. in some places the window straps sit out a little from the block/insulation so the tape whilst good , as it goes around the straps creates an air cavity in behind the tape.. will this create a plastering issue?

 

 

I am at the same point as you and experiencing the same issues.  How did you get on with the tape and plastering?

[Simplysimon]

tape needs split at bracket, pushed onto blockwork and more tape added each side to ensure airtight. back of p/board can be cut out to depth of backet if p/board fits tight to wall otherwise use enough fixative to make flush with bracket.

[Moggaman]

On 21/07/2022 at 16:37, KillyfadNewBuild said:

 

I am at the same point as you and experiencing the same issues.  How did you get on with the tape and plastering?

Sorry , haven’t been on in a while. I cut smaller pieces and wrapped them around the  brackets as best I could. Plasterers had no issue with them.