Gary G

Cladding options Marley board and render?

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17 hours ago, ProDave said:

is clad in 100mm thick wood fibre board and rendered with the Baumit.com thin coat render system.

So if your wood fibre is fixed directly to the frame and then rendered directly onto that, is there any reason why I couldnt fit EWI over my frame and render directly onto that? 

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18 minutes ago, Triassic said:

So if your wood fibre is fixed directly to the frame and then rendered directly onto that, is there any reason why I couldnt fit EWI over my frame and render directly onto that? 

 

A lot of the systems I have seen have a drainage channel between the insulation and the timber frame sheathing, which I would have thought would not be great thermally.  If you choose to do this make sure the system has a BBA cert and that BC and your warranty provider are on board.

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2 hours ago, Triassic said:

So if your wood fibre is fixed directly to the frame and then rendered directly onto that, is there any reason why I couldnt fit EWI over my frame and render directly onto that? 

A few things you need to consider.

 

First is racking strength and second is vapour permeability.

 

These were dealt with as a "system" by our designer.  The end result was the OSB racking layer (actually 2 layers) is in the inside of the frame as the OSB is less vapour permeable.  The Wood fibre on the outside contributes almost nothing to the racking strength and is more vapour permeable than the OSB

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1 hour ago, Triassic said:

@ProDave how does your system work and is it approved ?

I am not sure I understand the question.

 

It is a proven system in use and marketed in many places.  as to "approved" well it was detailed on the building warrant and agreed by building control.

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My architects design is for a layer of OSB on the outside of the frame for racking strength, thus is then covered with  layer of EPS fixed directly onto the OSB. I’m aware that others have applied rendering directly onto the EWI.

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2 minutes ago, ProDave said:

I am not sure I understand the question.

 

It is a proven system in use and marketed in many places.  as to "approved" well it was detailed on the building warrant and agreed by building control.

Mr Punter asked about BBA approval.

Edited by Triassic

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PorDave just reading this, no doubt it’ll provide some of the answers.

 

 

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10 minutes ago, Triassic said:

PorDave just reading this, no doubt it’ll provide some of the answers.

 

 

I had forgotten I posted that.

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5 hours ago, Triassic said:

So if your wood fibre is fixed directly to the frame and then rendered directly onto that, is there any reason why I couldnt fit EWI over my frame and render directly onto that? 

Facade designs which use a ventilated rainscreen are a safer option compared to the one you’ve just described.

Try reading this link about the problems experienced in Canada:

https://en.m.wikipedia.org/wiki/Leaky_condo_crisis

and the same design related issue in New Zealand:

https://en.m.wikipedia.org/wiki/Leaky_homes_crisis

Edited by Ian
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11 hours ago, Ian said:

Facade designs which use a ventilated rainscreen are a safer option compared to the one you’ve just described.

Try reading this link about the problems experienced in Canada:

https://en.m.wikipedia.org/wiki/Leaky_condo_crisis

and the same design related issue in New Zealand:

https://en.m.wikipedia.org/wiki/Leaky_homes_crisis

Some interesting reading there. Particularly useful is the NZ building code which contains some useful detail on waterproofing the xterior cladding to limit water ingress.

 

https://www.building.govt.nz/assets/Uploads/building-code-compliance/e-moisture/e2-external-moisture/asvm/e2-external-moisture-3rd-edition-amendment7.pdf

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It is worth being very careful that your warranty provider is on board with your proposal if you use external insulation on a timber frame without a cavity.  The Diffutherm system (no cavity, like @ProDave's) BBA states:

 

"NHBC Standards 2008
In the opinion of the BBA, the use of the NBT Diffutherm External Wall Insulation System for use on Timber Frames, in
relation to this Certificate, is not subject to the requirements of these Standards."

 

Where the ventilated systems all state something like:

 

"NHBC Standards 2016
NHBC accepts the use of the Jubizol CR External Wall Insulation System (Timber), provided it is installed, used and maintained in accordance with this Certificate, in relation to NHBC Standards, Part 6 Superstructure (excluding roofs), Chapter 6.9 Curtain walling and cladding."

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On 14/09/2018 at 22:38, Pete said:

That's the going rate. Had 5 quotes and all around same price. Not a DIY job and it is a timber frame so cannot use traditional render.

1

I realise its not a DIY job, but I'm unsure as to how I should be using to apply the render. For instance, my Plasterer says he does rendering, including the "modern stuff", or should I be going with a someone recommended by the manufacturer? 

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That is entirely upto you. I got a list of approved renderers and two where mad busy and due to the delay with my windows could not fit me in. One guy came all the way from Burnley and said he would love to do it and would send me a quote and I never heard from him again.  I eventually got a guy that  had been on the list only because I want the back up from the render manufacturer in case of any problems.

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