Thoughts on mixing push-fit with crimp connections?

I’ve seen those push-to-connect fittings cause some real headaches after five or six years. A buddy of mine used them for a shower remodel in his guest bath, and we ended up cutting out a chunk of drywall last Christmas because a seal on the hot side started weeping. Behind a wall, I always sweat my copper or use a proper ProPress if I've got the tool. Relying on an O-ring in a buried cavity just feels like gambling with a slow leak you won't catch til the subfloor starts rotting. As for the spray foam, that's a bit of an old-school trick to stop pipe chatter, but you have to be careful. If he used the high-expansion stuff, it can acutally put weird pressure on those PEX crimp rings or push the copper out of alignment. I prefer using plastic insulators or felt-lined J-hooks to keep things quiet. Mixing the blue PEX with copper is fine for a quick fix, but jumping between crimps and bite-fittings makes it look like he just used whatever scraps were left in the bottom of his van.

I’ve used SharkBite connectors in dozens of tight spots over the last ten years, including behind-the-wall applications, and haven't had a single callback yet. Most of the horror stories come from guys who skip the prep work. If the handyman used a proper deburring tool and marked his 1-inch depth on the copper before sliding the fitting on, that seal is as solid as any crimp. People get nervous about the O-ring, but those fittings are ASSE 1061 certified for a reason. The spray foam is actually a smart addition for noise dampening. I usally squirt a little around my 1/2 inch PEX lines where they pass through the 2x4 plates to stop that "water hammer" rattle. It acts as a decent insulator too. As long as he didn't gunk up the actual valve body or the swivel nuts, I wouldn't worry about the mix of materials. It’s a practical solution for a renovation where you’re trying to marry old plumbing to new without burning the house down with a torch.

I'm definitely new to this, but reading about that spray foam has me worried. If it expands and pushes the pipes around, could that actually cause a leak at those push-fit joints later on? I don't know much about how much pressure that foam really puts out. Also, is there a specific way to tell if he deburred the copper just by looking at the outside of the fitting, or is it basically a mystery once it's installed? I'd hate for my friend to close the wall if there's a simple way to check.

I stopped using spray foam for stability after I had to fix a leak in a wall cavity years ago. Digging out cured foam just to get a wrench or a cutter on a pipe is a nightmare and turns a twenty-minute fix into a two-hour ordeal. Now I just use solid blocking and plastic straps to keep things from rattling. As for the mix of fittings, I’ve found that using whatever’s on hand ussually means more leak points. I stick to one system per job so I only have to keep track of one set of failure risks. If it were mine, I’d swap those push-fits for crimps now while the wall is still open.

You're spot on about the nightmare of digging out foam. I'll add that when you use spray foam around copper specifically, you've got to make sure it's non-acidic. Some of those cheaper, large-gap cans can actualy react with the copper over time and cause pitting or corrosion. If he used the wrong stuff, the 'stability' he added is actually eating the pipe from the outside in. Between that and the push-fits, I'd definatly be keeping an eye on the ceiling below that bathroom.