Bonding coat to expanding foam

[FiveKnuckleShuffle]

Hi all. I've moved a light switch and done the bonding coat along the channel after sinking in the twin and earth etc.

I have a end part which is around 80 by 50mm which is just a void with nothing such as lathes for the bonding coat to adhere too.

Does anyone know if I can fill it with expanding foam and then bonding coat on top?

With being a ceiling it won't take any traffic like a lower wall or floor is what I'm thinking.

Any alternative ideas would also be appreciated. Thanks in advance

 

[robinbanks]

Use expanding foam to adhere a small square of plasterboard in there; the foam will bond well to the board and the board would be better to bond bonding coat to than cured foam

 

[FiveKnuckleShuffle]

Use expanding foam to adhere a small square of plasterboard in there; the foam will bond well to the board and the board would be better to bond bonding coat to than cured foam

Cheers. Anything else I can use instead of plasterboard. Its not cost but I hate waste and buying a full plasterboard for just a 50 x 80mm shape I'd be throwing over 90% of it away is all.

 

[robinbanks]

Any skip you pass? Bit of wood, tile, etc..

 

[FiveKnuckleShuffle]

Any skip you pass? Bit of wood, tile, etc..

SHHHHHHHHHHHHHHH

I went to B&Q and when inspecting the quality of the plaster board a corner piece just came off in my hand. I decided to not buy the plaster board based on this evidence. I did clear the mess up from the floor but as there was no bin I disposed of it after leaving the premises.