using cement board as external cladding

[Tom]

Hello all, just wondering if anyone has experience using cement board as an external cladding. We will be cladding our house with a mixture of wood and currugated sheets, but will have a plinth running around the base, approx 30cm high, that I plan to clad in a cement board. It will be buried a little bit to completely cover the Nudura.

I've been looking at this stuff: https://insulation4less.co.uk/products/easyboard-1200-x-800-x-12-5mm?variant=42173328195637

which says it is suitable as "exterior sheathing board".

Two questions: any reason why this isn't a reasonable thing to do, and any other recommendations of board to use? I need something without writing on it...

Thanks all

[Mike]

It's a long time since I've come across that, and the problem then was that they were brittle. However technology has moved on and that may no longer be a concern, or be non-critical in your particular situation.

 

If it's keeping the weather away from the structure - hard to know from your description -  I'd be wanting a product that has a BBA certificate . As far as I can see, that particular product doesn't have one.

[markharro]

This is prob what we will do too to cover our EPS base - what are you planning for fixings?

[jamieled]

We have an EPS passive raft type of foundation from AFT. It comes with a cement board type product bonded to the EPS, it looks a bit like block work when installed.

Edited July 28, 2023 by jamieled

[Tom]

1 hour ago, markharro said:

This is prob what we will do too to cover our EPS base - what are you planning for fixings?

I was just going to screw it to the Nudura, then it can always be removed/replaced if it needs to be

[Tom]

14 minutes ago, jamieled said:

We have an EPS passive raft type of foundation from AFT. It comes with a cement board type product bonded to the EPS, it looks a bit like block work when installed.

That's interesting, will have to have a look 

[saveasteading]

3 hours ago, Tom said:

a plinth running around the base, approx 30cm high, that I plan to clad in a cement board

This height of plinth is nigh on invisible in its context. I usually have this detail whether poured concrete or blockwork, painted in blackjack, and it then does become un-noticeable.

 

Nobody has ever, to my knowledge, remarked on the plinth at all (dozens/hundreds of projects).

[Tom]

Unfortunately the Nudura colour is a bit more noticeable, and our chickens love to peck at it, so needs something to cover.

[Gone West]

I used BluClad board to clad our plinth. It was around 450mm high so I covered it with brick slips.

 

https://www.insulationshop.co/10mm_bluclad_60min_fire_resistant.html

 

[Tom]

By 'eck that BluClad is £81/sheet!

[JOE187]

A cheaper option is to render with a mesh and base coat then thin coat render such as parex. 

 Robust finish that can take water splashing!!

[Gone West]

3 hours ago, Tom said:

By 'eck that BluClad is £81/sheet!

It certainly has gone up a lot in the ten years since I last used it.

[Russell griffiths]

I used aqua base render and mesh then a black acrylic render on top. 
covers the first course of Nudura brilliantly. 

[JOE187]

There are always small quantities of render and mesh on marketplace, and easy to darken/lighten the colour with a cement colouring powder!

[Tom]

Agree render or brick slips is probably the done thing but that Easyboard stuff, if it's appropriate, would be far cheaper than render etc at only £10 a board - and easily DIY-able. Could do a 40cm high plinth and get a 2.4m run out of each board. Would be good to see the board in person before pulling the trigger, though would only be a £350 gamble for our 85m perimeter...

[markharro]

On 28/07/2023 at 23:29, saveasteading said:

I usually have this detail whether poured concrete or blockwork, painted in blackjack, and it then does become un-noticeable.

Hi @saveasteading I have thought about painting but I dont think Blackjack would be compatible with the EPS we not to cover/hide?

[saveasteading]

43 minutes ago, markharro said:

but I dont think Blackjack would be compatible with the EPS we not to cover/hide?

 you are correct. I wasnt paying attention that it was eps.

Normal cement board will be fine then black.

Or maybe try a masonry paint direct on the eps? I've used it on osb when solvents in other paints have dissolved the binders. Try on an offcut

 

You'd think a system like nudura would have resolved this.