Thread: S Traps

How long have S traps not been allowed?

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Originally Posted by John Goad

How long have S traps not been allowed?

JG: I am thinking in the 1930s, but cannot support that idea. I am sure that JP has an old dusty volume lying around with that info. I think he was plumbing back then . . .

Thanks A.D., how about it Jerry can you tell me when?

Well, in my first life ... Ung told Unk to shave and Unk asked "With what? No shavers have been invented yet."

Okay, I don't know when 'S' traps were not allowed, but as I recall there was a discussion on this last year or so and someone found something which indicated they were disallowed back in the 1920s or so.

I could look it up on historical Uniform Plumbing Codes CD, but they are a pain to use and find things on.

The real answer is: "It does not matter when they were no longer allowed, they were no longer allowed for a very good sanitary reason and that reason still existed back when 'S' traps were being installed." Just because it took years and decades to prohibit a practice never makes that practice safe to have ever been installed, much less left to exist to today.

It's amazing how many houses around here have S traps. And not just the many, many very old houses. It's completely unsurprising to find them in relatively new homes. These things seem to vary considerably by region, it seems, as far as enforcement goes.

John, I called out an S-trap on a sink in a new home a couple years ago. The builder rep who was standing there said "Do you have S-traps in your house?". I said "Yeah, but my house is 110 years old. This is brand new".

I have to admit that I just stopped mentioning the presence of S-traps unless the house is newer as I just see too many of them.

This house was about 15 years old, although I did find one in brand new construction last year. I knew they had not been allowed for a long time, but just not how long.
Typical agent trying to say that the house did not need to be brought up to current codes, she also said she has never had an inspector mention wood debris in the crawlspace.

Originally Posted by Nick Ostrowski

I have to admit that I just stopped mentioning the presence of S-traps unless the house is newer as I just see too many of them.

Nick,

Does this mean that you no longer put them in your report, or that you do put it in the report but merely do not discuss it at the end of the inspection?

Originally Posted by Nick Ostrowski

John, I called out an S-trap on a sink in a new home a couple years ago. The builder rep who was standing there said "Do you have S-traps in your house?". I said "Yeah, but my house is 110 years old. This is brand new".

Nick,

They are a real easy fix.

All it takes is to slightly reconfigure the drain piping and install an AAV above where the drain where the trap is.

I know they're not a hard fix but nobody (from my experience) wants to bother with fixing them unless their drain is not emptying properly. If their sink empties and doesn't back up, they don't care.

S-traps don't even make my reports anymore.

Originally Posted by Jerry Peck

Nick,

They are a real easy fix.

All it takes is to slightly reconfigure the drain piping and install an AAV above where the drain where the trap is.

As long as the AAV is allowed by local code. A lot of newer homes that have had the kitchens remodeled by a non-plumber you will find an S-trap installed when the move the kitchen sink off the wall.

AS to when they have been not allowed depends on what code book you read. I have one here from 1918 where they did not allow S-traps unless they where crown vented. Also have a 1920 code book that says s-traps, bell traps, and crown vented traps are not allowed.

I bet if you called in the local plumbing inspector, or state inspector in case you do not have a local one, and they will tell you the S-trap needs to be removed and the drain properly vented.

Originally Posted by Nick Ostrowski

I know they're not a hard fix but nobody (from my experience) wants to bother with fixing them unless their drain is not emptying properly. If their sink empties and doesn't back up, they don't care.

S-traps don't even make my reports anymore.

S-traps drain great. Its not a problem with the draining, the problem is they don't stop draining they siphon out the trap and can be a source of sewer odors.

But then again as often as AAV's fail the S may not be all that bad.

Originally Posted by Nick Ostrowski

I know they're not a hard fix but nobody (from my experience) wants to bother with fixing them unless their drain is not emptying properly. If their sink empties and doesn't back up, they don't care.

S-traps don't even make my reports anymore.

N: If you were in Texas they would make your report or make you pay for replacing the traps.

Originally Posted by A.D. Miller

N: If you were in Texas they would make your report or make you pay for replacing the traps.

I ain't in Texas.

I don't call them out for repair either. They're extremely common in the Phila. area and you'd have a hard time convincing anyone that the risk is worth the cost to replace them.

Just thinking out loud, maybe the way to go is to include an FYI note in the report to the effect that "Sink drains in the house use 'S' traps. Modern plumbing standards no longer allow 'S' traps because they can siphon dry during drainage, potentially allowing sewer gases to enter the home. ..."

Wimpy? Asking for trouble?

John

Originally Posted by Phil Brody

But then again as often as AAV's fail the S may not be all that bad.

I have had AAV's in my homes for years and have never had one fail, I'm sure that they do fail but I have never found one that has failed.

I had a mechanical vent in my travel trailer fail a year after we bought it!

Originally Posted by Phil Brody

But then again as often as AAV's fail the S may not be all that bad.

Nah, an AAV may fail at some time.

"S' traps do siphon out frequently.

Big Difference.

Originally Posted by John McQuiggan

I don't call them out for repair either.

Wimpy? Asking for trouble?

Not calling something out just because you find it "all the time" is both wimpy AND asking for trouble ... for you, and Nick, and any other inspector who does not call them out because "you find them all the time".

Originally Posted by Jerry Peck

Not calling something out just because you find it "all the time" is both wimpy AND asking for trouble ... for you, and Nick, and any other inspector who does not call them out because "you find them all the time".

I'll bring this up for a vote at my next board of directors meeting Jerry.

These were in a 4 year old house in an area that does not have any code enforcement.

Originally Posted by Jack Feldmann

These were in a 4 year old house in an area that does not have any code enforcement.

If you called in a state plumbing inspector he will make that be corrected. Thats one of the few things that gets me burned up is when a DIYer on a DIY forum asks for help with a plumbing project and you tell them the right way to do it, they reply "Oh I do not need to follow any code since there is no one around to inspect it." We always tell them then, you may get away with it now, but when you go to sell your home, a Home Inspector will catch it then you will have to correct the mistakes then.