Sips panels and rendering

[Russell griffiths]

I just thought I would check something. 

On another group I’m a member of somebody is suggesting that they are going to build an extension with sips then a membrane and then cement boards screwed directly onto the sips, no battens no air gap or cavity. 

 

Now I’m sure that is totally wrong but they reckon it’s the correct spec. 

 

Who's the lunatic me or them. 

[SuperJohnG]

Them in my opinion. I have SIPS and I will be having a 50mm air gap then my renderboards. 

 

Albeit I am now very interested to follow this, only person I know with something attached directly to a kit is @ProDave with his wood fibre cladding which is rendered. Dunno know if thats nearly equivalent? 

 

following with interest. 

Edited January 18, 2021 by SuperJohnG

[Russell griffiths]

Pro daves place is timber frame not sips. 

[SuperJohnG]

Just now, Russell griffiths said:

Pro daves place is timber frame not sips. 

I know however his wood fibre panels (can't remeber what they are exactly) I think are directly attached? I might be making it up. 

 

It would be nearly the same thing. 

[SteamyTea]

I saw a stick built extension being built.  They nailed a mesh to the external OSB after the Tyvek breather membrane, then rendered it with concrete.

Seemed an odd way to do things to me.

[Onoff]

33 minutes ago, Russell griffiths said:

I just thought I would check something. 

On another group I’m a member of somebody is suggesting that they are going to build an extension with sips then a membrane and then cement boards screwed directly onto the sips, no battens no air gap or cavity. 

 

Now I’m sure that is totally wrong but they reckon it’s the correct spec. 

 

Who's the lunatic me or them. 

 

They're wrong but you're still a lunatic! ?

[Russell griffiths]

14 minutes ago, Onoff said:

 

They're wrong but you're still a lunatic! ?

I’m sure I’m not the one contemplating building a flux capacitor out of beer cans. ?‍♂️

[ToughButterCup]

57 minutes ago, Russell griffiths said:

...

Who's the lunatic me or them. 

 

You have to ask? Really?

[Iceverge]

1 hour ago, Russell griffiths said:

I just thought I would check something. 

On another group I’m a member of somebody is suggesting that they are going to build an extension with sips then a membrane and then cement boards screwed directly onto the sips, no battens no air gap or cavity. 

 

Now I’m sure that is totally wrong but they reckon it’s the correct spec. 

 

Who's the lunatic me or them. 

 

It might work if they had magnesium oxide based SIPS. 

[ProDave]

Yes my wood fibre is directly attached and then rendered no cavity anywhere.

 

https://www.natural-building.co.uk/system/timber-frame-render/

[ADLIan]

The above link references a BBA cert that appears to be no longer valid. The replacement certificate now includes the vent cavity behind the cladding system. Check MIs and  3rd party certificates for exact requirement, accepted good practice is that render should not be applied direct to TF or insulation on TF.