VCL - Barriair vs cheaper polythene performance

[BMcN]

I'm looking for some advice on what VCL to use.  I picked up some Protect Barriair stuff second hand, although I would probably need more to do the whole house.  

 

My question is, in terms or performance, is something like Barriair any better than say a 200mu polythene like THIS from Baufol or maybe a 125mu like THIS from Novia? 

 

I ask because the Barriair is 1.5m, so it will require a joint on every wall (2.4m and 1.8m high).  This will cost a lot more in tapes, increase wastage and give many more potential leak points.   The polythene can be ordered on 2.7 or 3m widths. 

[ProDave]

Bariar has a built in tape down one side to join it th the next strip.

[Jeremy Harris]

The major problem with ordinary polythene sheet is that airtightness tape will not remain adhered to it, due to it's very low surface energy. VCL materials are treated or formulated to have a high surface energy, so that their self-adhesive features or ordinary airtightness tape will adhere well to them and will remain well bonded for decades.

[BMcN]

10 hours ago, ProDave said:

Bariar has a built in tape down one side to join it th the next strip.

Yeah I had a test with it, no way I'm trusting that alone to seal.  Would probably still go Butyl and then a top tape on the lap. 

 

Thanks Jeremy, I'll have a think.  I could probably make the joints on polythene under the service batten strapping at top and bottom. 

[ProDave]

1 hour ago, BMcN said:

Yeah I had a test with it, no way I'm trusting that alone to seal.  Would probably still go Butyl and then a top tape on the lap. 

 

Yes I was not 100% happy with the built in tape. So what I did, if the joint did not coincide with a batten, then I screwed an offcut of timber over the joint to keep it pressed together.  A very good way to use up lots of scrap wood e.g offcuts of OSB ripped down into 2" strips.

[MikeGrahamT21]

The built in tape on the barriair is meant to form a tape to tape bond, which is very strong, but its hard to get a smooth seal sometimes, so I used both this and some more tape on the flapping bit of VCL to double seal it.

[BMcN]

Thanks, so general consensus would be stick with Barriair unless I could strap over the joints on the polythene maybe.