Our new tub is very vertical at the supply/drain side at the overflow hole. The drain fitting we have slopes backwards very slightly where it connects. The rubber gasket for the overflow is very steeply beveled (~1/8" to 3/8" thickness). It appears to fit better if the thick part is at the top and I've seen comments online that both say thick to top and thick to bottom.
When fitting thick to top, it fits closer, but not enough to seal the bottom. When fitting thick to bottom, it has a snug bottom, but a large gap after halfway.
I saw some posts saying you can rotate the gasket and get a good fit in cases where neither work and it seems to work that way. Everything at least fits, but is this a poor solution? I can't seem to get anything not quite as sloped. Would silicone caulk fix a thick top/bottom situation?
Best Answer
I would replace the rubber gasket you have with a more pliable foam-rubber replacement (commonly available at plumbing shops). This should allow you to place the gasket in the normal position (thick at bottom) but to give it a squeeze to effect a seal all the way around.
In the end, it is the seal at the bottom that is most important. Why? Because any water that gets to the overflow under normal circumstances is just incidental splashing and not likely to cause a huge problem. In the worst case (actual high water level, the reason for the overflow port), large amounts of water will be flowing through the bottom part of the hole. Any gap there will result in floor/wall/home flooding and damage.