Leaking faucet leaking shower mixer valve, turn on the shower tap leaks water thru the floor damaging basement ceiling..tested the drain that is good

You have a blockage on the hot water inlet to your shower valve . If all other hot oulets are fine . Take the valve out and check the mixer body for blockage . Or do you have a valve on the hot side that is not fully on .

hi mark.
this is all i could find on the internet,if this is no good to you go to the link at the bottom and see if it helps you out.
First, feel the water leaking from the tub spout or shower head. If it's warm, you know that the leak is coming from the hot-water valve. If the water has been dripping for a while and it is cold, the leak is probably coming from the cold-water valve. 1Start by removing the faucet handle.22 Nov 2016

How to Repair a Leaky Shower Faucet Valve - HomeTips

shower head leaks Google Search

I assume that you mean a leaking pipe. If it is leaking the water has to be going somewhere. If the shower is on the second floor then look for water stains on the ceiling of the room under the shower. If the shower is on the first floor go to the basement or crawl space and look for water signs there.

Water pipes throughout yoru house need to be drained, this is assuming that the water is actually turned fully off. Also, turn off the hot water tank, as sometimes that keeps expanding and pushing water. Open faucets in the basement and on the top floor to facilitate draining.

The most common reason for basement leakage is from the seal at the drain or the seal behind the overflow. With the overflow, the water trickles down after bouncing off your body and back onto the tub. This possibility MUST be eliminated first before determining the next step, Turn on the cold water and fill the tub and let the water go into the overflow for about 5 minutes. This will simulate someone in and using the shower. Check for leaks in the basement.

This test, as simple as it is, will also implicate bad plumbing connections at the valve itself behind the wall as well as eliminate backsplash from the showerer bouncing back onto your control valve(s).

If you have a leakage, wait a day and, with the drain open, turn on the hot/cold valve(s). and waste some water for another 5 minute test. This test eliminates the overflow as a suspect, and with the drain open almost always eliminates the drain as well. Hey..in plumbing there are no perfect answers.

If you still have leakage and no one is showering you have pretty well isolated the valve or connections to the valve. If you don't have leakage, it points to water bouncing off the body and onto the control valve(s) at which point resealing would be in order.

You can get leakage also if the caulking around the tub where the tub meets the wall has gone south. Stamped out steel tubs (common in rental apartments) have open corners so if the wall-to tub caulking is poor then the shower bounce off the body will easily trickle to the basement. This is not an issue with cast iron or fiberglass/plastic tubs.

If these tests truely point to the valve(s), repost your ? and refer to the drain tests completed, and supply as much information as you can about the brand and age of your valve(s)

Check around the the front of shower and make sure there is no place that water can seep thru such as old calk and or loose tile and around fixture molding

I would unscrew shower head pipe and either pipe dope it or tefilon the threads and then reinstall it. I would also take the handle(s) rosettes off and look for a leak from there with a flashlight, while shower is on. I believe the most comon leak for walk in showers are the door seals. Are you sure it is not coming out from under the door? Another test that yuo may want to preform is to Stopper the drain, fill the shower pan with water and watch for bubbles, or look for leaks from below.

SInce it is wet both under and behind the shower I would rule out the drain floor pan and drain system and think it most likely to be the pipe leaking from the mixing faucets to the shower head. Find studs directly behind shower faucet, n each side. Locate the center of the studs and put vertical lines up and down on the center line of the two studs closes to but outside the shower  faucet on each side. Approximate 6 inches or so  up and down for the height of the shower faucet (Valve, not head) Put Horizontal lines across between the two line at both the top and the bottom/ You now have a square.Using a Razor knife(Sometimes called a box knife, stanley 99a for example) cut into the lines of the square back and forth as deep as you can. Cut an x  acrossthe square corner to corner again as deep as you can . Lightly hit the center of the x until the drywall caves in . Cut the remaining drywall out for the square. Now while  the shower is running you will be able to see whee the leak is. Use pipe seal after disassembling the loose fiting or repair the leak iun what ever manner is necessary. Replace and repair the hole made in the drywall  with another piece of drywall, tape and joint cement. . 

turn off main water in home . turn on tap some where in home to release presser take shower handle off (screw under cap) unscrew the tap with a wrench unscrew on insides you pull out replace washer put all back togethere

Hi lorenzotwalk,

I'm Harvey the Master Plumber.

Your problem is: When you use the shower, water leaks through the ceiling.

First, since it only leaks when you're using it you can ignore the water lines. Now comes the detective work. Look very closely at any place the water can squeeze thru, i.e. cracks in grout or caulk, etc. Don't forget to look on the floor imediately outside the shower and around the shower door if any. If found it must be scraped out, cleaned and dryed to get good adhesion, then caulked with a high quality silicone caulk (color of your choise). Any other caulk will crack no mater what they say.
Let dry for 24 hrs.
If you havent found this kind of problem it's time to look at the drain line connection. You may have to open the ceiling to do this, that's why I'm always carefull in the first step. Turn the water on and watch the drain connection. If it leaks there, it must be repaired. In this case you might cunsider checking the Repair Directory for a repairman.

Feel free contact me again!
Please give me a rating here at fixya.com before you sign off
Thank you,
Harvey your Master Plumber