Rendering on 7newton thermal blocks

[Highline]

Hi can any1 give me there view on this topic please.
I have 2 new builds to render 2 coats.the only things is I've read a spec from Hanson which is not very detailed so there's no come back on then I think.they are saying that we have to slurry the blocks and they say. 6 sand 1 cement1 lime. I'm taking they mean top coat so there is no spec on the scratch.which should be 5:1 abit weak for me as usually use 4:1 .7newton thermal blocks shouldn't really have much suction due to being dense so I was wonder if any1 has just wet them down and rendered.
The slurry hasn't been stated its just an advisory .

 

[roughcaster]

It could mean (spec wise), you have to use an sbr slurry mix on the dense blocks first to form a key, for the scratch coat to grip onto. So do they mean,, sbr slurry coat, scratch coat, top coat???. I'd check it out first.

 

[Highline]

Yeah sbr slurry but top coat must be 6:1:1.
The trouble I have is just wondering if there is a lot of shrinkage on this type of block.

 

[ImperialCompleteSolutions]

The trouble I have is just wondering if there is a lot of shrinkage on this type of block.

A late post I know but no there is not much shrinkage in 7n blocks as they are very dense and do not suck in a lot of water !
Martin