Plasterjfe has a great point, we have just finished a job with 17,000 m2 of OCR3, there was loads of problems with cracking, reps came out from the start and every 4-5 weeks and said we were doing everything to there specs, after 80% job done cracks started appearing around heads, middle of walls, basically it could happen anywhere and everywhere, the rep just didnt want to know, the only way they wud av got involved if the blocks had a key that you could climb up, the temp had been a constant 15c with 2 geshia girls gently fanning the render for 2 weeks after application and no paint (unless thier paint) was applied. Never trust a rep, ever, ever ever. We once had a complaint with the 'white' pral was not white, the rep got out of his car and laughed 'thats not white' i siad it's supposed to be, he said no way!! he looked at the side of the empty bag and said 'yeah that's defantaly white' !! tossa, when threatend with court they paid out compo to paint it !!!!! In my opinion, 75% of reps are spreads that couldn't hack it on site!! rant over lol off t bed !!