hi,lads,when re skimming old lime plastered walls,how do you approach em,when prepping em? did one recentley,must of give it 3 good strong coats of pva & the suction was a nightmare. got called back from the customer as there was a few hairline fractures. he even said the other spreads who came to quote all commeted how grim the suction would be. you guys use gyprime or anything else to control it? cheers