Hi guys just looking for a bit of advice. I've got to skim a wall ( using multi finish) onto an internal cement render wall in an old house. The cement render hasn't been scratched so it has no key. I was just wondering whether i'd be ok to just PVA it a couple of times or whether i'd need to use gypbond or something similar. Only trouble is i don't think the customer would be too keen on paying 40 odd quid a tub for it. I'm a brickie by trade but was learned to skim but have only ever really done it on board and hardwall surfaces so any advice would be great. Cheers, josh.