Introduction

[John55]

Hi. I’m new to the forum but close to the end of my self build. I’m having a few misgivings about building with Durisol as building control are being very restrictive in what finishes they will allow. Even with the only certificated render, Parex, they will only accept it if I can show that the local wind driven rain index is less than 75. The only data I can find states that the whole of Cornwall is over 100. Does anyone have experience of similar issues?

John

[SteamyTea]

37 minutes ago, John55 said:

The only data I can find states that the whole of Cornwall is over 100. Does anyone have experience of similar issues?

About the rain in Cornwall.  It will stop again next month when the schools reopen.

[John55]

Unfortunately building control take no notice of the weather , just data and certificates. 

[Marvin]

3 hours ago, John55 said:

Hi. I’m new to the forum but close to the end of my self build. I’m having a few misgivings about building with Durisol as building control are being very restrictive in what finishes they will allow. Even with the only certificated render, Parex, they will only accept it if I can show that the local wind driven rain index is less than 75. The only data I can find states that the whole of Cornwall is over 100. Does anyone have experience of similar issues?

John

What options are they saying are acceptable?

[PeterW]

Ok so BCO should have picked this up when you submitted plans and not when you get to the end of the process !!

 

What you’ll need to do is find a copy of the  ISO standard and then someone who can do the calculation for you  

 

https://www.iso.org/obp/ui/#iso:std:44281:en

 

 ISO 15927-3:2009 shows the method for calculation based on local conditions and shielding etc - you’ll also need 10 years data from the Met Office for your most local location that can be used to provide the wind and rain statistics  

 

Assuming this was a full plans submission I would also be getting ready with a complaint to your building control department as they should have picked this up a long time ago … 

[ADLIan]

Agree this should have been picked up as part of the BR application. Looks like BCO is treating this as a solid wall - Appr Doc C gives info on when and how this is permissible. The render is not the issue, the whole wall construction should have been assessed. Is there a BBA, or similar, certificate for the Durisol system which would give advice on maximum exposure zone? Durisol should be able to help do the exposure rating calculation (BS 8104 according to Appr Doc C). This may show lower exposure rating if in a town centre with shelter from adjacent buildings. Otherwise you may have to look at tile hanging or some other form of rainscreen/impervious cladding. Have a read of Appr Doc C and question Durisol.

[SteamyTea]

I thought Durisol where history. 

[JohnMo]

New owners, so back from the abyss.

 

BBA certs are available if you do a search, would assume the build manual is still on their website, which has all sorts of info.

 

We have stone slips, adhered to the Durisol wall directly and wooden cladding.

[John55]

To be fair, our original plans were for membrane and cladding but we started looking at stone slips after seeing another self build and then porcelain tiles. Our local Durisol rep put us in touch with Steve Keitley (PRB Systems) who had previously worked for Parex, the only render with a BBS certificate for use on Durisol. He was very confident in his suggested combination of products but the BCO would not accept it without certification. 
Yes they are regarding Durisol as a solid wall, which it is. JohnMo what was used to stick your stone slips?

PeterW thanks for the info , I’ll check it out.