I live in an apartment house. When I want to take a shower I must let the shower run for 15 minutes before the tub drain starts working properly. I've had the building handyman up to look at the problem land he has snaked out the drain and put a gallon of bleach down the drain. All to no avail. Once approximately 15 minutes passes,the drain opens fully and drains the standing water in tub and continues to drain so that there is no water in the tub. Once I turn the water off and then restart, once again I have to wait for the drain to operate properly. Neither the building super or handyman has an answer.
Anyone out there have an idea?

We recently had a somewhat similar problem and one of the things we were advised (by three different people, all knowlegable about these things) to check is the vents in the plumbing system... the cause of our problems turned out to be a different kettle of fish, it still might be worth looking into.

Thanks for the response MrsS. My Super did mention that he thought it was a problem with the vent, but he claims fixing that would necessitate taking out the tub. I'll have to research his answer.

Michael

Older plumbing tends to sag, plastic ABS piping will definitely sag if it is not supported correctly. If a strap has broken or the pipe has sagged then you have a "valley" in the line. that valley will fill with water, causing a blockage which will require X amount of pressure behind it to 'push' it through. Once the water starts flowing it will pull water through the pipe.

It can take a few minutes to reach that point where enough water is in the system to siphon water through.

That's an interesting hypothesis. If that's the cause, then others in my line should be reporting the same phenomena ......I'll have to check. Thanks for the reply.

have the plumber snake the vent's