hi fellas, after reading one of the other threads i noticed a few of you lads were not impressed with anyone using a 3-1 scratch coat externally in which i did so a few weeks ago for me sisters garage. it's for my spar dash so the plan was to do a 3-1 then 4-1 as i was told the weaker the top coat then the stones can fall out quite easy? also i never treated the concrete blocks,just a sup of water,will that cause probs in the long run?