I need to bury pipes leading to 4 rads in screed. As I understand it burying any fittings in screed is a no go. Therefore I am using JG plastic pipe in JG conduit and doing long runs to each rad to remove any fittings. Question 1: Where the flow and return pipes meet each radiator there will need to be a fitting which will need to be buried in the screed. How fo you solve this if they cant be buried in screed? Question 2. Do I need to put lagging around the JG conduit?