Wrinkly membrane….

[G and J]

Well, we are back from our week away so it’s back to life, back to reality …

 

And the first question I ponder is what to do about the breather membrane on the front of our house.   For various reasons the front upstairs gable of our house has not had its timber outer skin put on.  Scaffolding has now gone up so that will be remedied soonish.

 

But what to do about the breather membrane?

 

It’s the expensive Tyvek reflective stuff supplied by ETE, the timber frame company.   It’s specc’d for four months exposed.   We’ve been a lot more than that.  It was put up in September.  It now looks a bit like my skin, rather more wrinkly than I’d like.  
 

The timber skin is 24mm larch which overlaps nicely so should keep the vast majority of the rain, etc. out.   I think the main functions of the membrane are to keep wet out of the frame, and to allow water vapour out so that any atmospheric moisture in the timber of the frame can escape.  
 

So do I leave the existing membrane in place and add another layer or is that likely to reduce the passage of moisture too much?

 

Or do I cut the existing stuff away and put new straight onto the OSB of the panels?

 

Guidance gratefully received, as always.

[Redbeard]

Perhaps ask the UK importers (?) of Tyvek. They will probably take the pessimistic view and tell you to replace (which I think is the way I'd err)  but if they suggest another course (leave it, or add A.N Other membrane) then you may have saved some time and a bit of extra cost.

[G and J]

Thank you Redbeard.  My thinking is that if there isn’t a downside to simply adding another layer them why not do that.  Reduces probability of leaks perhaps.  But logic doesn’t always work with building…

[torre]

I'd worry that two layers of breather membrane, especially when one has had its performance degraded somewhat, won't behave the same as one, and lean towards replacing.

 

Pessimistic I know but a lot cheat got than remedial work down the line

[Iceverge]

Pics ....

 

I am suspicious of the double wrap too. 

 

It might not always be as good an idea as first it appeared to be. 

[G and J]

 

On 16/07/2026 at 22:05, Iceverge said:

Pics ....

Sorry, forgot to post this.  Exhibit A : one wrinkly membrane…

[ProDave]

Apart from re taping the joints, that would not trouble me.

[Iceverge]

Yeah, that's fine.

[saveasteading]

Looks OK to me. I'd be inclined to staple the wrinkles back, then tape wherever it feels the right thing. If you can make any wrinkles lap downward then they won't hold any water. It will look much better and that is probably the only issue.

 

I've found huge differences in the quality of aluminium tape. 

The cheap stuff is a pain to handle and is weak. For 50% more from a proper BM it is certainly worth it.

The same applies to black tape: the official brands are very sticky but in a controllable way.

[G and J]

Ummm, I haven’t taped all the other acreage of breather membrane.   Bit late now as most of it is safely covered.   It’s all carefully lapped as per, but not taped.  
 

Should I add it to the list of tumble dryer thoughts I enjoy at night?

[Mr Punter]

Looks fine.  I would normally expect to see vertical stapled on tape to identify where the studs are.

[G and J]

22 minutes ago, Mr Punter said:

Looks fine.  I would normally expect to see vertical stapled on tape to identify where the studs are.

We’re using very short studs on our build lol

 

Our upstairs panels were delivered without breather membrane as the flanks had to be clad first in cement board.   So when we put the membrane on I just marked enough to level from.   

[Mr Punter]

Stapling the tape on may help straighten it up a bit. Get it clad ASAP.

[G and J]

38 minutes ago, Mr Punter said:

Stapling the tape on may help straighten it up a bit. Get it clad ASAP.

It’s on the todo list.  
 

I’ll soon be whacking on the vertical battens.  Horizontal soon after that.  The cladding takes a remarkably large amount of time. 

[Mr Punter]

On a gable with a raking roof abutment and windows, it is hardly glory work!