sand cement mix for bare brick prior to bonding

[Deansplit]

Hi, what's the mixture for sand and cement for a bare brick internal wall, prior to bonding and finish plaster? Also I have a load of building sand sitting in the garden from a project, will it suffice or is it strictly plastering sand you need to use – it's literally just for a 3sq m alcove next to a fire place which was previously badly damaged by damp, it's not like it's an entire room or anything.

Thanks for any help

Dean

 

[23vc]

You might get away with building sand but I wouldn’t risk it, you can buy 25kg bags of plastering sand. Mix wise, 4.1 scratch, 5.1 top. Or 5.1,6.1. Why are you bonding over it tho, normally render and skim in this situation?

 

[Deansplit]

You might get away with building sand but I wouldn’t risk it, you can buy 25kg bags of plastering sand. Mix wise, 4.1 scratch, 5.1 top. Or 5.1,6.1. Why are you bonding over it tho, normally render and skim in this situation?

Sorry, yes of course, no bond needed as it's brick! OK, but what do you mean by 5.1 top? As in sand and cement mixture? The top coat is plaster, it's inside. What's the reason for the different sands then and while not being ideal, what's likely to happen if I use building sand?

 

[23vc]

5 sand, 1 cement. The sharp sand and plastering sand is coarser grained and less likely to crack. Use plasticiser or hydrated lime too for workability.

 

[Deansplit]

But normal Carlite finish plaster goes straight over top of the sand/cement right?

 

[23vc]

Yes, nowadays referred to as thistle multi finish or board finish.