Advice needed - slow draining bathtub

[scrabble]

I'm a newbie and just needed some advice.

My tenants say the bath tub drains slowly after taking a shower (ie: water is at the level of the ankles after 10 min shower). They also complained that the bathroom sink faucet had low water pressure. I had the Super snake out the bath tub drain and it drained fine and the faucet water pressure improved.

Within a week, they complained that the bath tub was draining slowly again. When I ran the shower for 5 min, I didn't think it was draining particularly slow. But I had a plumber examine it, he power snaked the bath tub drain and it was draining fine.

Within a week and a half, they complained again that the bath tub drain is slow. I had the plumber come in a second time to examine it. He power snaked it again and again it drained fine. However, the sink faucet problem returned.

In all cases, the snaking did not retrieve a clog or anything.

Is there an explanation for why this keeps happening?

Is it reasonable for a tub to drain slowly so soon after power snaking?
Each time after the snake, the plumber has assured me that it shouldn't drain slowly anymore. But within a week or so, I get a phone call from the tenants.

What is the technical definition of slow draining tub? 30 sec? 60 sec?

Would power snaking it too often cause damage to the pipes?

I would appreciate any insight for how to approach this next time they complain. I don't know what else to do, since the plumber hasn't given me an alternative to snaking it. He doesn't think that the pipes are broken and it isn't a clog in the main line.

 

[johnjh2o]

Most clogs in tubs and showers are caused by the hair. Do your tenants have a dog that they're washing in the tub? Here is a link to a tool that may be of some help for you. The sink faucet problem has nothing to do with the tub drain.
http://zipitclean.com/

 

[scrabble]

They do have a dog and of course have denied washing her in the tub.

 

[Terdchaser]

Have you checked the vent line? Sometimes the upper part of a San tee can be partially clogged and this will interfere with proper venting also.

 

[FamilyPlumber]

I'm not sure what's slowing your drain. All I can say is that damaging the pipes is unlikely if the proper size of snake is used(based on the pipe), given that the plumber also uses it with extreme care, especially if you have plastic drains.

 

[plbgbiz]

...Would power snaking it too often cause damage to the pipes?...

If the snake damages the pipe, the snake was not the problem.

 

[AQualityPlumber]

This is most likely caused by old galvanized drain lines. I just posted an article about this. Even though the snake punches through the drain it is punching maybe a 1" diameter hole if you're lucky. Only way to truly eliminate this reoccurring problem is to repipe the drains in ABS or PVC. Then you will no longer have this issue.