Overflow drain testing in bath tubs and sinks

[Robert Foster]

I'm curious to know what percentage of inspectors fill bathroom tubs and sinks up to the overflow drains, in order to test that part of the drain piping for leaks.

I wanted to set up a poll, but I don't see how to do it on this forum. Is that something only an administrator can do here?

[Mike Lamb]

Email Brian Hannigan. I don't think you can do it yourself.

I have never tested the overflow intentionally. I have done it unintentionally twice. It leaked both times.

[Markus Keller]

I don't do it as a rule but will do it sometimes but try to avoid it.
I've had too many leak problems in the past where I've had to scramble to find buckets and towels to keep the floor below from getting destroyed; mainly on tubs and whirlpools.
Sinks - composite or standard type, rarely
Sinks - glass bowl or weird sink assemblies, pretty much always
Tubs and whirlpools - really try not to on upper levels, usually on lower levels
Earlier this year another inspector and I did a large house together. As a rule he always fills to the overflow. He's had lots of issues because of this but that's another story. We filled the WP up ran it, then started to drain it, then had to run to the alley to get a large City garbage can to catch all the water, and move all the dining room furniture to keep from getting destroyed.
On the flip side of 'if the WP hadn't been filled', would it be an E&O issue or what would have happened to the client once they purchased. Based on what was visible it didn't really matter. The house needed so much plumbing work the Plumber was going to be there for a week or more no matter what. The water tank needed replacement, weird leak signs were visible at lots of locations; traps were dry; the WP install was bad anyway, etc. Funny thing is I told him not to fill that stupid WP.
Lots of times looking at the overall conditions/install can really help one assess how taking a particular action may work out. Obviously you want to serve your client as best possible. On the other hand you don't want to damage someone's home.
Dishwashers are a good example. If you see water stain signs along the sides or under a dishwasher then you can figure it has been leaking. You could run it for a minute to prove it is currently leaking but you wouldn't want to run it and walk away to continue your inspection.

[Jerry Peck]

I have never tested the overflow intentionally. I have done it unintentionally twice. It leaked both times.

That is why I made it a standard practice to do - because I did it a couple of time unintentionally and it leaked each time - so I thought about all the ones that I had NOT done and wondered how many of those not checked leaked ... thus I began to intentionally check the overflows.

What better way to learn what TO DO than by unintentionally DOING IT and finding something which needs to be written up? Only better way I can think of is to learn from experience - and it is always better to learn from the experience of others than to have to go through the trouble of experiencing it yourself ... what is that saying? Oh, yeah:
- Good judgement come from experience. Experience comes from bad judgement ... :)

[John Kogel]

If you get paid to spend the whole day at the house like Jerry used to do, sure, fill 'em up.

On the other side of the coin, people can go their whole life and never overflow a tub or a basin.

Why not just print up a sticker "Do not allow this tub to overflow. It might leak". :D

[Eric Barker]

I don't run up to the overflow.

[Jerry Peck]

If you get paid to spend the whole day at the house like Jerry used to do, sure, fill 'em up.

Many (most?) inspectors in South Florida, those who did 2-3 inspections per day, also filled the sinks and tubs to test the overflows ... but that is a business decision based on the number of times leaks were found - it is up to everyone to make their own business decision regarding what is 'worth their time' and what is not.


On the other side of the coin, people can go their whole life and never overflow a tub or a basin.

True, but one leaking overflow can ruin your day when there is damage caused by it, and if no damage is caused by it, explaining why you should not be replacing the sink with the leaking overflow takes more time than having tested it. Everyone makes their liability versus risk versus time judgement calls.

[Raymond Wand]

No I do not fill tubs sinks. As far as tubs/shower stalls go, you could fill them and not find any leaks until someone actually gets in the bathtub and Bingo, there is a leak. So testing or lack thereof is not foolproof.

[Darren Miller]

I do it on new construction only. I have found several where the overflow was not tightened and leaked. Of course all the builders pointed fingers at me claiming I overflowed the tub.

[Jerry Peck]

So testing or lack thereof is not foolproof.

No testing is foolproof, it is all base on what one sees at the time, just like roof leaks, electrical ground faults, faucets leaking, etc. - I never based what I did on whether or not it was foolproof, nor, I suspect, did other inspectors down in South Florida where I inspected.

[Scott Patterson]

If I have access to view under the tub, I fill them to the overflow. I would say that 30% of time I will find a leaker! Most of the time the soft rubber washer/gasket is missing, the fixture has been tightened too much deforming the washer or it is not tight enough.

With sinks I seldom fill them to the overflow. If the overflow channel has rust spots I will test the overflow. Honestly more and more sinks do not have overflows...

[John Kogel]

Glass bowl sink with no overflow, I say " Do you have kids or grandkids visiting? Remove the stopper."
I am seeing them now with just a screen in the drain, no stopper. Someone is finally cluing in. :D

With a big faucet, one of those sinks will fill to the brim in less than a minute.