Given that you have galvanised steel piping and are installing something prone to eventual failure in an inaccessible location, use whatever works and don't worry be happy. Sorry if that comes across as snide. At the least, install good components with suitable-for-your-water materials in a way to permit future repair. You could transition the respective metals to a CPVC union and avoid galvanic reaction.

jjam, Auto parts stores sell something that looks like a stethascope with a tube on the end for listening. There should be an access panel for the shower piping if there is a closet on the other side of the wall. Sounds like the piping was not installed/anchored properly. If you can see piping in the basement, try to slightly bang on the piping to see if you can recreate the noise. Shock absorbers or water hammer arrestors work best when placed between the last two fixtures on the longest run of piping. Air chambers were typically placed on the incoming main water supply line, but become water logged and require draining to introduce air so they work again. If the holes that were drilled for the water lines are larger than the piping, you can put a small piece of pipe insulation into the gap to avoid the banging. The big box stores also sell "J hooks" for supporting piping runs. Hope that helps, Dan Martyn

Hi Nicholas, I think you could get better help over on the plumbing forum. But make sure it's from someone who understands that plumbing is different in a manufactured home (the preferred term to "trailer") than in a site built home. Another helpful resource might be mcgarryandmadsen.com. They are home inspectors and have a blog, including numerous entries about manufactured homes (MH), in which they are experts. I'm guessing you are coming to this site because you can't afford a plumber, or because you are an experienced DIY-er. I understand about not having money--believe me!!--I do. And I understand about doing as much DIY as possible. But I highly recommend, if at all possible, to at least have a qualified, licensed plumber who is knowledgeable about MH plumbing, inspect the plumbing under the house and tell you what exactly is wrong. I have a lot of DIY knowledge (but can't do a lot of it anymore due to my disability), but the two things I will never touch are electricity and plumbing. You really need professionals for these. Even if you DIY, you will still need a permit and have the work inspected. If you don't get the work permitted and you ever sell the MH and the home inspector finds unpermitted work (and a good inspector will), you will not be able to sell the home until you get a permit and have the work done right and pass inspection. If they miss it, and you sell the house, if something ever goes wrong and the house floods or something, the new owners can force you to pay for all the damage. I hope this is helpful information. Whatever your situation, I wish you good luck and all the best! If you ever have anymore questions about MHs, please don't hesitate to ask. :-) Sincerely, Debbie

Is the valve soldered on too?? I would put in a new valve - it will have the proper end to run the flex lines for the faucets.