Bursting pipes sound like spraying water, although I have heard some homeowners sound like mad elephants when they discover a burst water line.

If you are at all doubtful about the identification of the piping material, I gently suggest that your plumbing experience does not exist. My point earlier is that every material has certain physical and chemical characteristics (properties). Use of materials requires that users design and install to accommodate those characteristics. All materials have a coefficient of thermal expansion. Most increase in size as they are heated. Not even Congress can change that. I suspect that your hot water pipe is moving as the temperature of the pipe changes. It grabs and then slips in the clamps/supports, making the noise. Dogging it down even further would be the worst solution. The piping WILL MOVE AS THE TEMPERATURE CHANGES. Using supports and layout designs that permit the piping to move freely as necessary without creating noise is the better solution. A good plumber knows and understands the material involved and designs/installs accordingly. Copper has a coefficient of thermal expansion greater than that of iron/steel. Most plastics are considerably greater (COE) than copper.

Stopping sound transfer. 1. - some density 2. - complete air block More complete explanation: 1. At least one layer of dense material. 2. At least one layer of an air block, which could be the above, dense material, or could be foam. Goal is no air flow. So do not let outlets cut into your air block; you have to 100% seal all five sides of the box. Spray Foam is excellent for this. Do not use fiberglas insulation in the wall cavities for this project as it does not meet either criterion #1 or #2. Neither one. It can be used as a minor padding, if you happen to have a ton of it lying around waiting to be used somewhere. Sheets of the cheapest open cell foam are better however. Density: Double layers of 5/8" fire code drywall which is denser and heavier in its body than 1/2" drywall, will be more effective than double layers of 1/2". Density: Buying and installing cast iron for the stack makes sense here. All plumbers will confirm that it makes much much less noise than plastic stacks when water flows down it. Sealing plastic pipes with foam is a workaround, not what I'd call a solution compared to buying cast iron. If you do not put any padding in the wall cavity, you run the risk of letting the wall cavity reverberate like a drum under certain frequencies which cannot be predicted in advance. You may hear higher pitched sounds but not rumbling, for example. So prudence dictates adding some foam in there too. HTH -david

First off, that is not a J-bend. A J-bend is a straight length of pipe with a 90deg bend on the end. The pipe is question here has a 180deg bend and it is properly called a "Return Bend". When that return bend was initially made they began by making a straight return bend without a cleanout hole. They then drilled a hole at the cleanout location slightly smaller than the desired finished opening and the tubular brass of the bend was then swaged out to form the finished shape and size at the cleanout location. A short piece of threaded brass tubing was then inserted into the opening and soldered in place and finally they screwed the cleanout cap on the end of the threaded brass tubing. In this case over time the threaded brass tubing corroded and fused into the cleanout cap so that when the cleanout cap was turned instead of the cap unscrewing the solder joint broke and the treaded tube came out of the return bend. If you examine the section of brass tubing extending out of the cap in the last photo you can see where it was originally soldered into the tubing. That problem is quite common when working with old tubular brass fittings and generally Plumbers do not even attempt to remove the plug, but rather they take the entire return bend off to open the line for cleanout. It was mentioned that this is an "S" trap, which is illegal, but that is not correct. It is true that S-traps are now prohibited by code and may no longer be used for Plumbing, but here we run into an issue of semantics. "Plumbing is defined as the act of initially installing a piping system whereas the act of repairing an existing system is defined as "Maintenance". When performing Maintenance we are required to maintain exactly the original configuration, therefore given that an S-trap was code approved when that line was first installed you are required to replace it with an S-Trap. If you were to move that sink or do a rehab on the bathroom that involved changing the location of any fixtures or the physical configuration of any of the piping you would then be performing an act of plumbing and as such, all plumbing within that room would have to be brought up to the code that is in effect at the time the rehab is performed.