Plastering over expanding foam

[AndyBaldock]

Dear All,

I’ve a plasterer coming on Wednesday to sort out a small room but I’ve got some prep work to do. I need this hole filling in. I was going to use cement and old bricks but it’s angling down and will be hard for me to get anything to stick.

If I fill the hole with expanding foam will plaster stick to it? And if so, will I need to hack it back so he can attach some dob and dabbed plasterboard?

Thanks,

Andy

[wine~o]

No it won't ... you'll need some sand and cement in there followed by bonding...

Doubt you'll have time for that to set in that timescale.

[AndyBaldock]

Ohh dear. Thank you. I’m terrible at knocking up sand and cement.

[wine~o]

buy a small bag of ready mixed mortar (wickes/b and q etc.) just add water and mix up in a small bucket. Not too wet or it'll slump.

[AndyBaldock]

Thanks WineO. I’ve cement and sand in the shed. Am I to assume it’s a 4:1 ratio?

[wine~o]

4/1 is about right, but looking at that hole you'll need summat to slow down setting, plasticiser for instance else it'll dy out too quick and crack...

[AndyBaldock]

Thanks Wine O. All done. Now to wait and see if it cracks.