Our plastic bathtub is about twenty years old. Recently, it has started making creaking and popping noises when my wife or I shower. It also feels as though it is shifting or moving slightly under foot.

How serious is the problem?

Would going under the house to inspect the bathtub be of use? If so, what do we look for?

What do we need to do?

Keith

Make the trip. You may be ripping out the tub and possibly replacing some flooring.

Sooner or later you're going to have a drain seal that will rupture. The flexing,(unless it's cracked) can be fixed by puddling mortor mix under the tub to firm it up. You can also block it up with wood if you wish. After looking under the tub if you see signs of water around the drain let me know and I'll walk you through ressealing the drain lip. Good luck, Tom