Need to patch some areas of plaster, I have been advised to use a salt retarder additive (previous plaster had become mouldy due to new double glazing and lack of ventilation-now solved).
I have googled but the only salt retarder I can find is a salt retardent plaster at around £30 a bag. Reading the specs this seems overkill and I would need several bags, is there a cheaper alternative?
I was hoping to be able to just add a liquid to the render to acheive desired result.
Any ideas?
Glenn