Rendering on cement board - exterior

[Adam2]

The side of my house (ICF) forms a boundary wall which is covered in 10mm cement board - this is on the neighbour's side so I wanted to have some physical and fire protection in the unlikely event that anything bad happened. The wall is at the back of their garden behind bushes etc so worst case is a future garden fire out of control I think.

 

The adjoining garden walls - blockwork - will be sand/cement rendered.

To render using sand/cement on the cement boards - should we:

 

prime the boards with something

tape joints with jointing tape

Sand cement 4:1 base coat / top coat

 

Or is this doomed to fail?

 

I'm not doing this myself but builder is soon to start on the sand cement render on the regular block sections so I want to make sure the spec is right for this area. Luckily he can do the hidden parts on neighbour side of wall before he does my side so I can see how it looks.

 

Or, maybe this section we could just fill & paint to match the walls if rendering is going to be a problem.

 

 

[Mr Punter]

I would use Weber LAC with sheets of fibre mesh embedded.  3mm thick and can be rubbed up to a sanded finish.  Don't get it on your clothes it will not come off!

[nod]

It’s not really worth using sand and cements if you are looking to save money 

You would have to mechanically fix stainless mesh as the s&c would be to heavy for fibre or primer 

 

Something along the line of mr P suggestion would work 

Render base coats can be floated up to a smooth finish 

[Adam2]

great thanks chaps will look at Weber LAC