Hey guys, I just have a couple of basic plumbing questions and was wondering if anyone could help me out. I'll post pictures below to show you what I mean.
1) First, I have recently installed a tub and wanted to check the new plumbing I installed for any leaks. So I went under my home (it's on a cement slab) in the crawl space and checked my plumbing. I had a friend run cold water in the tub, and had him fill up the tub to check the overflow, and then had him drain the tub and run the water for about 20 minutes. I did not find any direct leaks, however, I did find quite a few large droplets right around the perimeter of the drain. I think it's just condensation, but wanted to check to see if anyone that that this was normal and rust-safe since it is on the side of the steel tub that is not covered in porcelain-enamel. So is this amount of water expected and is it hurtful in any way to the tub bottom in terms of rust or anything?
2)Second, I had removed my toilet during the tub install and just reinstalled it. But there is a leak coming from behind the toilet where the plumbing attaches to the toilet tank from underneath. It is not coming from the lower valve, it comes from the attachment point near the tank. And it only leaks when the toilet is flushed. Does anyone know the common issues with this leak? Will plumber's putty between the plastic nut and the porcelain tank fix this leak or is there supposed to be a gasket?
3)Third, before I removed my toilet, there was a wet patch right around the base of the toilet in the cement floor (when we used to have vinyl tiles there, the tiles would get damp as well in that area). It is always damp. I never could find the origin for it. When the toilet was removed, the patch dried up, so the moisture was a result of the toilet being there and being used. When I reinstalled the toilet with a new wax ring and everything, the wet patch came back. If the toilet is installed, but not used for a couple of days, the wet patch will dry up. So it has to do with the toilet flushing. The leak doesn't seem to be coming around the base of the toilet though (even though there is no caulking yet, I don't think the caulking is the issue since even when the toilet was installed before with caulking, it would still form a wet patch). What do you think is causing this wetness. It's not totally troublesome, but whenever there is a minor leak anywhere in my home I would like to address it to prevent future damages.
4) My steel tub used to have its drain and overflow installed in a cement patch. When I had to put in a new drain and overflow, I had to chip away that cement slab and expose the crawl space underneath. Now I need to seal the hole up a bit and was thinking about using Great Stuff foam for this. But I don't want to seal up everything, just the gap between the tub and my cement floor to prevent direct cold air and pests from coming up into that space. If I don't totally seal up the steel tub, will it rust since it is not covered in porcelain underneath and the tub bottom will be exposed to some elements since my crawl space is just mud? The only reason I don't want to completely seal it up is because if there is ever a leak directly by my drain, it will simply just fall down into the mud crawlspace under my house.
5) Last and final question is when I am ready to tile my surround, I am going to use durock cement board... and I have watched some videos and read some information about this process. Seems that people suggest using quarter inch shims around the tub to create a gap between the durock and tub for tub expansion during showering. You then just fill in the space with caulking. I was wondering if people do this around the vertical joints between two pieces of cement board as well? To allow for expansion so your tiles and grout don't crack, etc. Here is a video showing the need for spacing between the tub and cement board. They mention this issue at 1:18 in the clip. Here is the link:
Below are the pictures of my situation