Qual Pex Easy Crimp Aluminium Fittings in Concrete without Tape

akbar

Getting my house re-plumbed and the plumber is using Qual Pex Easy Crimp fittings. The metal on the fittings is aluminium. The pipes have been laid in a branch configuration and there are a lot of joints around. Many of them are buried directly in concrete. None of the fittings have been taped over, nor have room for expansion. There are also multiple sections of hot and cold supply pex buried in concrete without any lagging. They're all buried in sub-floor in a range between 2-5 inches below surface.

From the Qual Pex manual, burying joints is generally not recommended. If it can't be avoided, they say

"If jointing is necessary, or if the fittings will come in contact with

cement, lime or soil, wrap the aluminium rings directly and

completely using polythene building tape or PVC insulation tape or

similar. Also, allow 1% for expansion and contraction."

They don't say much more, but reading up on aluminium in concrete indicates there are corrosive effects on the aluminium, plus structural effects on the concrete due to the release of hydrogen.

Do I need to dig out all of these piping joints and re-lay them with proper protection against the corrosion? I'm not sure if this poses a major problem to the integrity of the jointing. At the minimum, it looks fairly certain this install wouldn't be covered by manufacturer guarantee in case of failure.

Are the un-sheathed sections of pex also a major concern? There are at least two sections (around 2M long, one hot and one cold) of 3/4 inch pex, and one 2M section of hot 1/2 inch, currently without lagging. There may be more, but these are what I've incidentally found so far, when making an adjustment to one section of pipe, and seeing some shenanigans.

Any advice is much appreciated