Advice needed on cultured marble shower basin

[DENNYSERMERSHEIM]

We have a 35 year old cultured marble walk-in shower. The entire front of the shower is open with a 48" door installed on a 3-piece marble curb. The shower basin is flat with no raised edges around the perimeter. The shower curb was made of three pieces of marble with the shower door installed on the top flat piece. During replacement of the shower door I discovered that the shower basin was leaking under the curb. When I took up the 3-piece marble curb I found that there is a plastic T-shape flashing installed between the flat marble slab the the shower curb. The plastic flashing was itself pieced and broke as I took it out. I have attached a few pictures. Including a picture of the T-shape flashing. If I put the original 3-piece curb back in I assume I need to replace the plastic flashing between the curb and the slab. Does anybody know where I can purchase the flashing? Or is there a better option?

[cx]

Welcome, Denny.

I can't envision what you've got there from your description. Perhaps you could post a photo or two of what you see? Use the paper-clip icon above the Reply dialog box to attach photos from storage on your computer.

[DENNYSERMERSHEIM]

Thanks CX. I revised my original post hopefully to be a little more clear. I also added three photos of the shower, including close-ups of the plastic flashing that is left sticking out of the wall.

[cx]

I'm actually quite surprised to see no real water damage under the part you've removed. My experience with manufactured marble showers is that they're guaranteed to leak waaaay before their 35th year. Usually first at the drain as I've not seen an adequate waterproof method of attaching the drain to the floor in those showers. All of mine have been over concrete SOG, fortunately. Your application would make me very uncomfortable.

But you didn't stop by to determine my comfort level, did you now?

I've never seen that plastic molding you have. And I'm not seeing a good way for you to replace it if you did have a new one. Do you know if they used something similar at the wall/floor junctions? Just difficult for me to grasp a caulked joint in an assembly like that remaining waterproof for 35 years.

My opinion; worth price charged.