Hi all, hoping there are answers out there to my small dilemma. A customer of mine wants 15mm radiator flow and return pipes chased into the block wall and pop out down the bottom. Problem is the joists are close to the wall so to start the chase in the block i will have to notch out the joist but I'm sure this is in the no notching zone. The joist is 8 x 2" or 22cm x 5cm the joist is around 3 meters so i can notch up to just shy of a meter from support either side. Any ideas or ways to chase the pipe into the block or cannot it be done? Im hoping to just surface mount when the wall is plastered as no one likes cleaning up after chasing in pipes. Thanks in advance.