When you have problems with sewer gas smells around a
fixture, there can be a number of causes.
1. Sewer gas coming back up into the home
a. Blocked vent.
b. No vent.
2. Leaking drains that cause rotting below the floor.
3. Moisture that causes mold buildup.
4. No trap on your sink.
5. One roof vent on septic system.
6. Toilet needs to be reset and calked.
Sewer gas can come back up into your home, when the
trap completely empties after a letting the water out
of a fixture, when the trap dries out, or when it is
sucked out by another fixture flushing. When water
goes into a pipe, it first has to push the air ahead
of it, if there is no place for it to go, it comes up
the trap. This causes a buildup of pressure if there
is no vent.
If there is a vent, the pressure is relieved up to the
roof, carrying with it all of the yucky smells. When
the water runs down the drain, the air behind it has
to be replaced, if its not, the pipes will try to suck
it from some drain...typically the shower drain, but
sometimes the floor drain when its close to a washer.
When vacuum draws air in through the trap on the
laundry tub it also takes the water out of the trap,
leaving an opening where the sewer gasses can come
back up from the septic system .
Think about your pipes as if they are a drinking
straw. When you put a straw into a glass of water,
the water fills the straw. But if you put your thumb
over the end of the straw and pull it out of the
water, the water (or liquid) stays in the straw. This
shows you, air has volume. When you remove your thumb
from the end of the straw, the water flows back into
the glass. This is the principal of a vent.
So if you only have the smell when a fixture is
running, the trap is refilling after the fixture and
blocking the sewer gasses from coming into the home,
but your vent is probably not functioning.
In addition, if you have only one vent up through the
roof on a septic system, you can get sewer gas smells
coming up through your home. As the wind blows
across the roof, it pressurizes the plumbing system.
Since the septic tank is full of water, the wind
cannot go into the septic tank. So it bubbles up through the
traps into the house. Installing a vent on an
opposing roof pitch, helps to relieve the pressure buildup,
since the wind then is only hitting one side of the
roof.
Floor drains are succeptable to this type of pressure.
If your drains are partially clogged it can work
similar to a clogged vent. Since there is no place
for the water to go, it forces the air, which is much
lighter up through traps, bringing sewer gas into the
home.
If your fixture is not set right or is wabbling, the
traps or wax ring that seals it underneith may not be tight.
When this happens, if you empty the fixture, sewer gas
will come under the sink into the room.
Each of these senarios will require a different
solution. The key to solving your problem, is having
the right questions to ask when the plumber comes out
to look at it. The previous information should
provide you with a basis for the questions you need.
Make sure before you call a plumber to check
cleanout covers and pipes to see if they have
openings to the sewer. If you have an opening
without a trap, you will get sewer gasses.
In conclusion, if you don't have a vent inside the
wall which equalizes the air pressure inside the
pipes, if you are on a septic system with only
one roof vent, if the vent is clogged off due to
sludge and soap scum, if you don't have a proper trap
on your sink, or if the drain is clogged, sewer gas can escape
into your home.
Good Luck
Raymond
Thanks for visiting our Web site! Hope this information helps.
The information we provide on-line is general in nature and not
specific
plumbing advice. Call our local office for a service call to diagnose
and
resolve your specific problem.
Raymond VinZant
To
Jennifer Canavan
10/05/2005 03:17
PM
cc
Subject
Sewer Smells fixture
Alex:
When you have problems with sewer gas smells around a fixture, there can be a number of causes.
1. Sewer gas coming back up into the home
a. Blocked vent.
b. No vent.
2. Leaking drains that cause rotting below the floor.
3. Moisture that causes mold buildup.
4. No trap on your sink.
5. One roof vent on septic system.
6. Toilet needs to be reset and calked.
Sewer gas can come back up into your home, when the trap completely empties after a letting the water out of a fixture, when the trap dries out, or when it is sucked out by another fixture flushing.
When water goes into a pipe, it first has to push the air ahead of it, if there is no place for it to go, it comes up the trap. This causes a buildup of pressure if there
is no vent.
If there is a vent, the pressure is rerouted up to the roof, carrying with it all of the yucky smells. When the water runs down the drain, the air behind it has
to be replaced, if its not, the pipes will try to suck it from some drain...typically the shower drain, but sometimes the floor drain when its close to a toilet. When vacuum draws air in through the trap on the toilet it also takes the water out of the trap, leaving an opening where the sewer gasses can come back up from the septic system .
Think about your pipes as if they are a drinking straw. When you put a straw into a glass of water, the water fills the straw. But if you put your thumb over the end of the straw and pull it out of the water, the water (or liquid) stays in the straw. This shows you, air has volume. When you remove your thumb from the end of the straw, the water flows back into the glass. This is the principal of a vent.
So if you only have the smell when a fixture is running, the trap is refilling after the fixture and blocking the sewer gasses from coming into the home, but your vent is probably not functioning.
In addition, if you have only one vent up through the roof on a septic system, you can get sewer gas smells coming up through your home. As the wind blows across the roof, it pressurizes the plumbing system. Since the septic tank is full of water, the wind cannot go into the septic tank. So it bubbles up through the traps into the house. Installing a vent on an opposing roof pitch, helps to relieve the pressure buildup, since the wind then is only hitting one side of the roof.
Floor drains are succeptable to this type of pressure.
If your drains are partially clogged it can work similar to a clogged vent. Since there is no place for the water to go, it forces the air, which is much lighter up through traps, bringing sewer gas into the
home.
If your fixture is not set right or is wabbling, the traps or wax ring that seals it underneith may not be tight. When this happens, if you empty the fixture, sewer gas will come under the sink into the room.
Each of these senarios will require a different solution. The key to solving your problem, is having the right questions to ask when the plumber comes out to look at it. The previous information should provide you with a basis for the questions you need.
Make sure before you call a plumber to check
cleanout covers and pipes to see if they have openings to the sewer. If you have an opening without a trap, you will get sewer gasses.
In conclusion, if you don't have a vent inside the wall which equalizes the air pressure inside the pipes, if you are on a septic system with only one roof vent, if the vent is clogged off due to sludge and soap scum, if you don't have a proper trap
on your sink, or if the drain is clogged, sewer gas can escape into your home.
If the septic pumper did not put the cover back on right to the septic tank, it could be leaking and the smell drifting up to the bathroom, through a window.
Good Luck
Raymond VinZant Plumbing Prof.
