Hi, I am in the process of getting my new home's concrete floor prepared.  We have geothermal air as a primary heat source, but thought while we have the basement slab open we should put radiant tubes in so the floor is warm. The manifold will be on an interior wall which is not built yet.  What is the best way to support the manifold?  We have the elbows to put on the supply and return tubes as it comes through the concrete.  How should it all tie together so we can get it tested?  Do we have to pressurize the tube before pouring? The manifold may get damaged during the pour.... Thank you!!!

often a temporary backer of rebar and plywood is used to support the manifold. tubing should definitely always be pressurized prior to a pour and it should remain under pressure until all puncture risks are over (control cutting, wall plate installation, etc).

there are often pressure test kits for different MFG's manifolds. alternately you can use a test rig for a single loop and connect all your loop heads together temporarily. this is easier or harder, more or less expensive depending on what you are using for a fitting system.

Thank you for your response. I bought some elbows to tie all the loops together. They will have to be cut off after wards, but it may save the manifold from getting damaged during the pour. Went to Home Depot and they gave me the fittings to do the test. Now we have to make sure the elbows are straight coming through the concrete. Can I put these on pressure treated wood and leave the wood in the concrete?

sure. I have a manifold with that detail in my shop actually.