Comparing heavy duty breathable underlay.

[epsilonGreedy]

Now that summer has ended my plan is to put down the roof underlay asap once the trusses are up. This means I have to plan for a period of exposure before the roof is slated.

 

Having trawled the forum for discussions on breathable roof underlay here is my short list.

 

Tyvek® Supro/Supro Plus

https://www.dupont.co.uk/products/tyvek-supro.html

Weight=145g, Strength=245&300, Exposure=4 months

Price £135 (ex VAT & 50m x 1.5m)

 

Protect VP400 PLUSLR

http://www.protectmembranes.com/uploads/ddd45e1cb3584a908c2ffb62079b4bb1.pdf

Weight=197 or (170?)g, Strength=305&325, Exposure=?

Price £86 (ex VAT & 50m x 1.5m)

 

Cromar Vent3 Pro

https://www.cromarbuildingproducts.com/wp-content/uploads/2020/07/Vent3-Pro-Breathable-Membrane.pdf

Weight=166g, Strength=270&300, Exposure=3 months

Price £86 (ex VAT & 50m x 1.5m)

 

Should I add another product to my shortlist?

@PeterWrecommended an underlay in a recent thread but I cannot find that.

[Mr Punter]

Why not get the roof slated straight away?  I would rather the roofers did the battens as well.  You could just fit some temporary battens, so they don't need to fit the membrane.

[LA3222]

@epsilonGreedy I used Roofshield, everyone I've spoken to say its the best you can get. Not saying it is or it isn't, just what I was advised so I rolled with it.

[Russell griffiths]

I used the Cromar vent 3 pro, don’t buy it from e bay there are a few adverts for seconds knocking about. 

 

 

Have you thought how you will put this on, without installing your battens you will find it hard to reach up onto the roof much more than a metre, imagine standing on the scaffolding with the facia at knee high you can only lean in so much before you end up in the room below, 

you normally roll a strip out and batten it then stand on these battens to fit the next row. 

 

Unless somebody  has had come up with a cunning plan I don’t know of. 

[PeterW]

I use MKMs version of Vent3 which is about £60/roll but is just rebadged Cromar. 

[Temp]

I used the Protect VP400 on an out building. Was exposed on both walls and roof for many months with no problems.

[dnb]

Proctors roofshield on mine too. Was suppliedad part of the SIPS package. It seems a very good product but I haven't had much to do with any others. 

[Cpd]

Just be aware that Proctors roofshield  and some others will become quite useless if while exposed to the weather they get wet and then freeze, it’s that time of year when this is going to be a potential problem..... I talk from experience on this one....?