How big does the hole in the backer board need to be around the shower valve? My current hole is big enough to remove the cartridge clip. What is the purpose of the large hole pictured in the directions? Larger hole=greater chance of leaking?
Shower – the proper hole size in tile backer for a shower valve
showertilevalve
Related Solutions
Glad you found your answer.
I've also had slow leaks (drips) like you experienced due to (1) solder spatter inside the valve that prevented a good seal on the rubber, and (2) plumber soldering the pipe with the cartridge in place which hardened the rubber so it didn't seal well.
It looks fairly standard to me. I'd contact Eljer & see if Danco, Brasscraft or someone else has put out a replacement that fits. Otherwise, have you tried to rebuild the old valve with O-ring replacements & such? Eljer should be able to direct you to the right kit for the valve.
On the other hand, soldering will be difficult & could cause a fire in the wall if you're not experienced. So, either get a Plumber or get a SharkBite Threaded connector so you can just cut the old valve loose & wrench in the new one. I updated the picture to show the correct valve that has screw shut-offs or stops (the silver screw).
Related Topic
- Shower – the term for a bathroom tile which wraps around a backerboard edge
- Water – why is the unfinished shower wet
- Walls – How should I attach glass panes for use as shower walls in place of tile
- Plumbing – What valve should I use for water control flow after upgrading to thermostatic valve
- Moen Shower/Tub Valve Identification / Water temp issue
Best Answer
There is no official size for it. As long as the trim can cover it, it's good. I usually use the provided template. That works for most trims.
The benefit of the large hole is easy access to the valve in case you need to repair it. For example, my value has 2 screws allowing me to block the water from flowing to the chamber holding the cartridge. If I need to replace the cartridge, I don't need to shut off the water of the whole house.
There isn't a greater chance of leaking. As long as you have the proper seal/water proofing at the edge of the hole, you will be fine.