Hi guys 1st time posting so please go easy on me.I have just finished scratch coat on my blockwork extention 3-1 mix with waterproofer (start strong come out weak)what is the best top coat mix,the top coat will have chippings thrown on (if that is the correct term)need good advice that's why I'm on here to tap into all that knowledge plus. If I get it wrong the missus will. Kill me.