Shower Pan Flexes When Standing On It

[mike81]

We recently moved into a house that was built about 20 years ago. I'm remodeling the master bathroom. There is a shower similar to the one in the picture. We have not used it yet, but I noticed that when I stand in it, the shower pan flexes near the center drain. It sinks maybe 1/8" - 1/4". Is this normal or something to be concerned about? It is on the top floor if it makes a difference.

 

[Crackplumbers]

This type of shower usually calls for the installer to place a dounut ring of concrete on the floor before installation, this is never done, this was and is one most common service calls.
A water mark is usually seen on the roof below, to keep this shower in your remodeling would be a mistake as it eventually do this.

 

[Crackplumbers]

There is a simple fix to keep this shower in your remodeling, but it involves getting to ceiling below the shower. If this is possible, I will explain further if you wish.

 

[mike81]

After looking again, I think it moves 1/16" - 1/8" at the most. The shower is directly above the garage, so if I needed to I could get to it. Here is a picture of the actual shower. The actual drain below the base does not move. It's just the piece that the drain cover attaches to. It slides up and down slightly when the base flexes. I hope I'm explaining that right.

 

[mike81]

There is a simple fix to keep this shower in your remodeling, but it involves getting to ceiling below the shower. If this is possible, I will explain further if you wish.

I'd be interested in hearing your solution. Thanks for your time.

 

[Crackplumbers]

The problem with flexing shower drains is that stress usually ends up causing a leak at the shower drain or the arm of the piping going to that drain.
This why I suggest this plumbers trick, cut a half inch ring of pipe out of the pipe below shower, half way between the P-trap and the shower outlet, then put a Fernco fitting over this cut (of the size of the pipe) half on eachside of the cut, now fasten the two gear claps that came with the fitting over that to secure it in place. You have just added a shock absorber to the piping when it flexes. A Fernco fitting is a vulcanized rubber sleeve with two high quality clamps.

 

[mike81]

The problem with flexing shower drains is that stress usually ends up causing a leak at the shower drain or the arm of the piping going to that drain.
This why I suggest this plumbers trick, cut a half inch ring of pipe out of the pipe below shower, half way between the P-trap and the shower outlet, then put a Fernco fitting over this cut (of the size of the pipe) half on eachside of the cut, now fasten the two gear claps that came with the fitting over that to secure it in place. You have just added a shock absorber to the piping when it flexes. A Fernco fitting is a vulcanized rubber sleeve with two high quality clamps.

I don't think the actual drain is flexing. When the pan flexes, the part the drain cover attaches to moves down, but the pipe it is attached to stays still.

 

[havasu]

Just a thought, but if you have an opening under the pan, it could be filled with NON-expandable foam, which will stop the flex. This can make it messy down the road when or if repairs are needed, but it will stop the flex.