Two storey extension: blockwork, scratch coat, finished roughcast

What we did

This is the whole job in three photographs: bare blockwork, the scratch coat on, and the finished roughcast. It is the clearest example we have of what is actually happening under a finished wall.

The scratch coat is the part nobody sees and the part that decides whether the job lasts. It levels the blockwork, gives the top coat something to key into, and is combed so the next coat grips. Rush it, or put it on a wall that is too dry or too wet, and the finish will crack along the joints inside two winters.

The top coat then went on to match the original house, which is the point of a new extension: it should be impossible to tell which bit is new.