Rendering/boarding in a catnic box lintel (bsd100).

[Spark & a half]

Hi Plaseterers!

We've knocked an internal wall through and will soon install the box lintel.

Building is 1960's, so generally sand/cement on internal blockwork throughout.

The beam has lots of holes in it; does that mean I can render it in direct?
Or is it best to board it like you would with an RSJ?

I can plaster a bit, just slow! But if sand/cement can be used I'd rather do that. Got the pillars to bond out as well.

Whilst on the subject, what's the best mix for internal rendering?
Building sand? Plastering sand? Or sharp sand? Or a mix of all!

Fairy liquid? Or plastersiser?

Mmmm a few questions!

Any help appreciated.

 

[Alastairreid]

No you cannot render directly onto the lintel.
Double plate and skim it.
Render...plastering sand 4-1 with plasticiser...admix.