i am about to put my lead upstand on block work so it can be pebble dashed to/ over . Ideally I would was going to screw and plug the upstand to the block work - then Put a stop bead over where the screw are so it will be hidden by the pebble dash? Is this method ok- for me it will be cheaper and quicker to do than chasing and turning it into the wall. Just worried about the lead expanding and contracting causing the pebble dash to crack? Thanks