"Foam sleeves help reduce noise, but they're often just masking the real issue."
Fair point, but honestly, foam sleeves aren't always just a band-aid. Had a similar issue at my place—pipes were secured fine, pressure was normal, and arrestors didn't do much. Ended up using foam sleeves, and it's been quiet ever since. Sometimes the simplest fix actually is the right one... just saying.
Foam sleeves can definitely help, but I'd still keep an eye on things. Had a similar noise issue myself—foam solved it initially, but after a few months the knocking came back louder. Turned out the pipes were expanding against some framing studs, and foam alone wasn't enough. Ended up adding extra padding between pipes and studs, and that finally fixed it. Foam sleeves are good, just make sure you're not overlooking something bigger...better safe than sorry.
Good call on checking beyond just foam sleeves. Had a similar issue at my place—thought foam would do the trick, but turns out the pipes were rubbing against a joist. Ended up having to reposition them slightly and add some felt padding. Been quiet ever since, thankfully. Curious though, did you notice if temperature changes made your knocking worse? Mine always seemed louder when the heat kicked on...
Yeah, I've definitely noticed the temperature thing at my place too. Whenever the heat kicks in, the knocking gets noticeably louder... I always figured it had something to do with the pipes expanding and contracting as they heat up and cool down. A plumber friend once explained how metal pipes can shift slightly when temperatures change, especially if they're tightly secured or rubbing against wood. He suggested using plastic clips or brackets instead of metal ones to give the pipes a bit more flexibility during expansion. I haven't tried that yet (my felt padding fix seems to be holding up for now), but it's an interesting idea. Did repositioning your pipes help reduce the noise during temperature swings, or is it mainly quieter overall? Curious if the felt padding alone was enough or if repositioning made the bigger difference...
Interesting you mentioned the plastic clips idea—I actually tried swapping out some of my metal brackets for plastic ones last winter. I was skeptical at first, since it seemed like such a small change, but it surprisingly made a noticeable difference. Before that, I'd tried felt padding too, and while it did help soften the noise a bit, it didn't completely eliminate it. Felt padding seems great for muffling the sound of pipes rubbing against wood, but when it comes to the loud knocking from expansion, it didn't quite cut it for me.
When I finally replaced a few metal brackets with plastic ones, the pipes had more wiggle room to expand and contract without making those sharp knocking sounds. It wasn't perfect—still got some minor creaks here and there—but definitely quieter overall. My guess is repositioning your pipes probably helped even more because it reduces direct friction points where pipes hit structural elements. But honestly, switching to plastic clips was easier than repositioning everything, especially in tight spots behind walls or ceilings.
One thing I noticed though... if your pipes are really snug against the wood framing or joists, even plastic brackets might not completely solve the issue. In one particularly stubborn area near my laundry room ceiling, I ended up using both plastic clips and felt padding together as a combo fix. That finally quieted things down enough that I don't wake up at night wondering if someone's banging around in my basement.
Curious if anyone else has experimented with other materials like rubber-lined clamps or silicone sleeves? Seems like there are a lot of DIY solutions out there...
