Sewer oder at cast iron house P-Trap (floor, drain, sink)

[johnintranets]

i have a 140 year old house and we are getting a sewer oder near the cast iron P-trap where is exits the house. I have looked at the pipe and i dont see any weeping or cracks. Can the smell be permeating the pipe itself?

[mathjak107]

i bet it is leaking somehow . no odors can permeate the pipe or water if it is in the pipe .

[LIcenter]

Is there a thru wall vent just above that trap?

[mathjak107]

if the vent is blocked you get cavitating and the p-trap will get sucked dry , good point .

[AksarbeN]

Originally Posted by johnintranets

i have a 140 year old house and we are getting a sewer oder near the cast iron P-trap where is exits the house. I have looked at the pipe and i dont see any weeping or cracks. Can the smell be permeating the pipe itself?

There can be a buildup of bacteria on the inside walls of the drainpipe before it connects to the P trap. This buildup will smell similar to sewer odor. Pour about a quarter of a cup of hydrogen peroxide slowly into the drain to cover the inside walls and leave,,,, don’t turn on the water for several hours to allow enough time for the peroxide to do it’s trick. Repeat again if necessary.

[johnintranets]

Originally Posted by LIcenter

Is there a thru wall vent just above that trap?

The closest vent is about 6 feet away. when i opened the cap on the trap there is plenty of water in it.

[johnintranets]

Originally Posted by AksarbeN

There can be a buildup of bacteria on the inside walls of the drainpipe before it connects to the P trap. This buildup will smell similar to sewer odor. Pour about a quarter of a cup of hydrogen peroxide slowly into the drain to cover the inside walls and leave,,,, don’t turn on the water for several hours to allow enough time for the peroxide to do it’s trick. Repeat again if necessary.

The problem is on my 4 inch pipe in the bacement just before it leaves the house not a sink drain. I would think i would need a lot of peroxide to get down there. What about a product like bio-clean or something similar.

[QIS]

Can you see ALL around all of the piping before it leaves the house or is some of it lying on the ground? Have you examined the leaded joints where the piping is sleeved together?

[AksarbeN]

Originally Posted by AksarbeN

There can be a buildup of bacteria on the inside walls of the drainpipe before it connects to the P trap. This buildup will smell similar to sewer odor. Pour about a quarter of a cup of hydrogen peroxide slowly into the drain to cover the inside walls and leave,,,, don’t turn on the water for several hours to allow enough time for the peroxide to do it’s trick. Repeat again if necessary.

Originally Posted by johnintranets

The problem is on my 4 inch pipe in the bacement just before it leaves the house not a sink drain. I would think i would need a lot of peroxide to get down there. What about a product like bio-clean or something similar.

Wow,,,, well you could pour than a quarter of a cup then. The purpose is to cover the sides of the pipe (even if it’s a larger 4” drain) with something that can kill the bacteria, you’re not looking to fill up the pipe. Hydrogen peroxide is fairly inexpensive for a quart sized bottle. It’s less of a cost than most other products to kill off bacteria odor.

Are there any “other” sources for the odor??? Maybe a mouse or rat that got inside the basement anywhere and died? Or maybe a sewer rat that came up the pipe towards the house and got stuck in the P trap?

.

[AksarbeN]

I’ve seen places where this sewer odor smell strong and none of the building engineers or maintenance people could find the source. It ended up being a floor drain p-trap. The water evaporated and the gas was coming up into the room. The drain was located in a back corner of the large storage room under a stack of shelving. Once they poured water into the trap it stopped.