Hydronic tubing leak in slab

Drzzzz1

I'm dealing w a 24 yr old large grade slab w pex tubing & 30% inhibited propylene glycol. There is a very slow leak in 1800 sf of slab, approx 1 gal 60 days. This is a new problem since last winter. The slabs have 2 areas, each w white fuzzy crystals over 1-2 sf. There happen to be very small cracks in each one, but this is a series of 8 garages in a large blgd ski lodging, and there are multiple similar very small cracks w no white crystals

Any ideas... could the white fuzzy crystals be propylene glycol?

Jamie Hall

Maybe not the glycol, but a decent indication of some chemical from the concrete, alone of combined with the glycol, reaching the surface in solution and evaporating.

Good luck…

mattmia2

But it also could be water from some other source making its way up through the slab. might be worth hiring a leak detection company to find it. Pex is flexible enough that it would take a lot of movement of the slab to break it.

HydronicMike

Fire it up, shoot it with a thermal imaging camera

hot_rod

I have has some success with Fernox hydronic leak sealer if it is a tiny leak like that.

Always best to find and repair it, but under a finished concrete floor, I would try a sealer as recommended by the manufacturer. More is not better with sealers.