100% vapour resistant board available anywhere?

[freddiemercurystwin]

OK a long shot but a shout to the professionals on here.

Anyone know of a board product (for instance something like Aquapanel (but not Aquapanel as its not vapour resistant)) that is 100% vapour resistant? In my day job I work for Architects and we’re trying to source a board that will also double up as a vapour barrier. It’s going in a cold (8 degrees C), internal & wet environment and at present the wall construction is Aquapanel, dpm and then 100mm Kingspan all mechanically fixed to the existing masonry. Prior to the insulation the existing masonry is to be coated with two layers of RIW. Note this is going on the inside of the walls as our project is going inside a (high brow, sensitive & listed) existing building and we have to protect the existing substrate from any possible damp penetration. As an alternative to this solution we’re looking to get a bespoke sandwich panel made up with a suitable board factory bonded to the insulation and doing away with the dpm so the whole lot can be fixed to the walls with an adhesive. Oh it needs to have a smooth finish too!

This is essentially a cost and noise reducing (no need for thousands of holes to be drilled) exercise.

I am in talks with the supplier of a board called Superflex but am awaiting written confirmation of its vapour resisting properties but this has not been forthcoming and without written confirmation it is a no goer and I am getting doubtful it exists!

Before anyone asks, I seriously cannot reveal the exact nature of the project is as if the press get wind there will be a witch hunt!

Regards

Freddy

 

[jeds]

Could you not use a thin thermal laminate - pur foam being closed cell and completely vapour proof. The joints would be the problem but that could be overcome by double boarding.

 

[mointainwalker]

Doesn't foil-coated PUR meet this requirement ?

 

[freddiemercurystwin]

AFAIK PUR can absorb a little moisture which is fine in a conventional situation as if it absorbed a minimal amount for instance in a damp cavity or wherever it can dry out again however in this situation it is going to be permanently exposed (albeit behind some Aquapanel) to a wet environment 24/7 365 days/year. The problem is getting a manufacturer to state in writing that it will resist moisture 100% and they will not. I have asked them. Same goes for adding foil to the face, it’s a good barrier but is it 100%? The joints can be taped with foil tape but again in a laboratory all well and good but not on a building site!

The building is leased by the client, the landlord is a nightmare and will have no qualms about terminating the lease should it be proven that any moisture whatsoever has leached its way into the existing structure hence a seemingly over-the-top solution is required.

My latest solution is a laminated board made up of 100mm insulation + 1mm PVC + 12mm Aquapanel. Yes there will be joints although these will be either rebated or tongue and grooved and sealed with silicone.

There does not seem to be a guaranteed way to do this, that's why the RIW is being applied to the existing wall beforehand, as a back-up.

Edited following further discussions with Kingspan.

 

[Deluks]

Before anyone asks, I seriously cannot reveal the exact nature of the project is as if the press get wind there will be a witch hunt!

Gary Glitters new basement recording studio?

 

[joinerjohn]

Before anyone asks, I seriously cannot reveal the exact nature of the project is as if the press get wind there will be a witch hunt!

David Cameron's new student and water cannon proof , bomb shelter??