I have a shower that is leaking on the floor board under the tub towards the left-hand side of the floor. After I take a shower for 20 minutes and I go into the basement you can see that the water is running along the floor. We have regrouted and caulked. We have made a access panel in a closet to get to the pipes however, there is no water there or wet spots. This afternoon my husband decided to cut another access panel to expose the pipe from the shower head and still nothing. I am afraid if it goes on much longer that we will loose the floor under the tub. We do have an old tub but in great shape. It's probably from 1960's when the house was built. Could the tub have a pin hole that is not visible?

Any suggestions?

Could be several things. Where is the dampness? Front back?

Hey Sherry... welcome to both you and Home repair... ;)

Sounds like you covered the basics...

You cut access panel by the tub waste assembly.. yes?

You have access to waste pipes in some way and have eliminated this as source of leak... yes?

You cut access by the shower head... yes?

You regrouted and recaulked... yes?

This suggests that you may have some tiles that are loose that you can't really see... even though you recaulked and regrouted.

Tap on the tiles around the side and back wall. If you hear hollowish sound or see any movement then you probably found the culprit! Otherwise caulk line between tub/wall may be issue?

This is all about investigating things one step at a time. Here, may be best to start on fresh day... then, fill the tub to the rim using only tub spout. Then drain the tub and see if leak appears.

If that results in nothing... then run the shower for 20 minutes... anything now? If not, then put someone in shower for 10 minutes... leak show up now?

You might be surprised to find that most of the leaks occur when someone stepped into shower and water bounces off person to some tile that has loose grout line... Hmmm... maybe?

Try these things... look inside and outside shower... let us know what you think...

MARK

It could be a leak from the tub drain. Could your husband find any wet spots at all and could he see the drain pipe?

I doubt that your tub would have a hole in it, especially if it is a heavy cast iron tub. There are several places that water could get out and on to the floor or into one of the walls around the tub. Do you have a soap dish or a grab bar? These are places that water can get into the wall. Does your spout drip water back against the wall, if it does it could be running a slight stream of water down the side of the tub. The overflow pipe sometimes loses it seal against the tub and the shower water hits there and can go down the outside of the drain and onto the floor.
Look for all possible places before you start tearing things up.