Old house plaster patching

[willsamyh]

Hi there, would be grateful for some advice on this. I need to patch from bare brick as you can see in photo and want to know what the best undercoat is. It’s an old cottage and it’s solid wall so chance of damp even just small amount. The bonding that came off practically fell of so clearly wasn’t adhering to the wall. Is SBR then sand and cement a good option for this case? Can give more details. Thanks a lot

 

[blup]

Sand and cement should be fine, PVA it first. If there is damp let the wall dry out first and treat any sources e.g. dripping gutter or broken drain.

Or dry line it (dot and dab).

Blup

 

[tell80]

Dont use cement - use a 4:1 sand & NH lime mix.
Dont use PVA on an outside, solid wall (or any potentially wet wall).
Dont attempt to patch - knock off all bonding, and then do the full wall and reveals in the above mix.

There an obvious drill & insert "damp proofing" cream line of holes - has the outside been drilled and treated?
Your joist tails will probably sit in pockets in that wall - they could have been affected by rot?
Photos of the outside esp. at ground level would help?
Do you know where the DPC course is - do you know where air bricks are around the house - do you know if the ground level is 150mm below the DPC line?

 

[willsamyh]

Thanks. Ok I won’t use PVA. I’ll take the rest of the bonding off. Would you use Limelite? Drying time appeals to me. DPC has been injected from just inside (outside is rendered) because no sign of a DPC. Yes there are air bricks about 150mm above ground

 

[tell80]

Limelite is fine but very expensive.
If damp is rising or penetrating from outside thro the render then you wont get drying time - thats why I asked for photos.

 

[willsamyh]

Ok thanks will take photos in daylight