Does anyone understand this configuration

[platforminc]

Hi All.


I am currently building a side extension spanning the length of the house, below is the specification from the architect.

Would anyone be kind enough to explain this to me in laymans term, what the wall composition will be from the outside/externally, the various layers and the materials.

I also want to know if 100mm Celotex insulation can be used instead of this configuration where 2 different types of insulation boards are used.

Will there also be any problems if aqua panel cement boards are used instead of EMS/Sand cement render.

Thanks in advance.

 

[^woody^]

You really should ask whoever did the crap spec, as he should have done a section drawing to illustrate how it is built, rather than just a cut and paste text from his last job.

Its render, on mesh, with a membrane, on treated timber battens, fixed to your timber frame.

You can't use 100mm insualtion on its own, as then you will have uninsulated strips on the internal face where the timber studs are.

You could potentially use 100mm in the frame and then 25mm or so across the inside before plasterboard.

You can't use a single layer of cement board, as the finish will crack on the joints as the frame flexes.

 

[platforminc]

You are spot on, its a copy and paste job. When I look at other plans they have submitted for other people. its same thing.
I will ask for a section drawing now.
What some plasterers have told me is that instead of using mesh as in EML, why not use Knauf Aqua panel. They said EML was a very old method. When I challanged architect, he said I wanted to keep costs down, and this was the way to do it. What annoys me is that the aqua panel method might just be a tiny increase that is negligible, I was not given that option though.

Builder was suggesting 100mm as you described it, then we can use a 32.5mm insulated plasterboard to finish off from inside

You really should ask whoever did the crap spec, as he should have done a section drawing to illustrate how it is built, rather than just a cut and paste text from his last job.

Its render, on mesh, with a membrane, on treated timber battens, fixed to your timber frame.

You can't use 100mm insualtion on its own, as then you will have uninsulated strips on the internal face where the timber studs are.

You could potentially use 100mm in the frame and then 25mm or so across the inside before plasterboard.

You can't use a single layer of cement board, as the finish will crack on the joints as the frame flexes.

 

[^woody^]

What some plasterers have told me is that instead of using mesh as in EML, why not use Knauf Aqua panel.

Be careful with those. They might be the same plasterers that want to use dry lining instead of bond and skim, and this is because they are not proper plasterers and just want an easy flat surface for them to skim over.

You need to be careful with rendering over any board externally because of cracking. It needs to be properly designed and specified. There are cheaper boards than aqua panel too. Google for something like " Eco cement boards " and that will throw up various types.

 

[freddiemercurystwin]

It's not just some EML though, and tell your architect that Rendalath doesn't actually exist anymore, its Stucanet Lath now.

for detail see here though https://www.diynot.com/diy/threads/rendering-timber-wall-frame.233481/

 

[^woody^]

Riblath is still made by Expamet

 

[freddiemercurystwin]

Ahh my bad, I speed read it and my brain read Rendalath!

 

[tomfe]

You can quite happily do a thin layer render system with fiber glass mesh over render board.

 

[John D v2.0]

What I want to know is what the benefit of a void within the insulated layer? Presumably he's going for a warmer wall construction than it flush to the inside, but whoever builds it will have to be very careful to stop air movement in the void.

 

[^woody^]

What I want to know is what the benefit of a void within the insulated layer? Presumably he's going for a warmer wall construction than it flush to the inside, but whoever builds it will have to be very careful to stop air movement in the void.

It's a crap design.

 

[tomfe]

deja vu

 

[^woody^]

Deja crap.

I'll look forward to the next post in November