ICF meets timber meets steel - render query

[Adam2]

Our ICF (Nudura) house is up, steels all in and we're preparing for windows and thinking about render finishes etc

 

We have a few areas where we're not sure how best to proceed - have asked engineer and architect so will see what they come up with

 

One of them is this steel section over what will be sliding doors with a course of blocks over it:

 

What's the best way to bring that out so that when we render it we don't get cracks? Was thinking to mechanically fix EPS onto the blocks, steel and the small timber ladder in-fill section (just visible beneath) all to the same depth as surrounding EPS so when it's rendered hoping the mesh will help bridge the gaps over these 3 different base materials. Or should we also then put cement board across the EPS to create a more stable base?

 

Not sure if any other options?

 

 

 

 

 

 

[willbish]

EPS, as looks like that section needs insulating 

[Adam2]

Yes absolutely needs insulating, that was the intention - just wanting to make sure the EPS over these 3 materials and then rendered will be stable  so not likely to start cracking across the joins if I take this approach

[nod]

If you go the EPS route You will have to make sure the knock ins can be firmly anchored 

Or you will get cracks 

I would put a frame in insulate and use vent board to carry the render 

[Adam2]

Thanks @nod so a frame over the block, steel and timber infilled with EPS and strip of ventilated soffit board along the bottom edge? This is based on my guess on what a vent board is

[Conor]

We covered all bits of timber and steel with either render board or EPS. I bought a bail of 25mm and 50mm EPS for this purpose. If that steel needs to be insulated, do the full depth in Eps. Normally it's better to fix a timber batten first, but of you don't have the depth, fix directly with stainless steel fixings and expanding foam (low expansion ewi foam).

[nod]

2 hours ago, Adam2 said:

Thanks @nod so a frame over the block, steel and timber infilled with EPS and strip of ventilated soffit board along the bottom edge? This is based on my guess on what a vent board is

Correct 

[Adam2]

Cheers will draw a pic to make sure I communicate this will to others