Sewage Smell After Adding a Toilet

Significance

• The hydrogen sulfide and methane in sewer gas can explode when exposed to open flame or sparks. The Wisconsin Department of Health Services warns that these and other chemicals can also cause hydrogen sulfide poisoning and asphyxiation. Any opening that can allow this gas to escape into your bathroom could also permit water or even small creatures. If you smell sewer gas coming from a newly installed toilet, then some aspect of that installation has failed to seal the area between the toilet and the drainpipe firmly.

Flange Placement

• Sewage smells can rise up from an improperly seated toilet flange. The toilet flange, a circular ring that sits in a recessed area of the floor underneath the toilet bowl assembly, secures the toilet to the drainpipes via a series of bolts. Tim Carter, writing in the Washington Post, warns that if the toilet flange’s top surface sits unevenly or at a height more than one-half inch above floor level, the wax gasket that normally seals sewer gas inside this assembly may allow the gas to escape. Sometimes the addition of new flooring can alter the floor’s level in relation to the flange.

Other Issues

• A skimpy wax gasket can sometimes cause a sewer gas leak. When installing a toilet, you must select a wax gasket ring thick enough to provide a tight seal between the drainpipe and the outside world. Sewer gas that manages to get past the wax gasket will often escape through the unsealed openings in the bolt holes or slots. A toilet that appears to have a solid layer of caulk running around its base may nevertheless emit sewer gas smells in this manner.

Solutions

• Plumbers can sometimes correct leakage by attaching flange extenders or adding extra gasket material for a tighter seal. A damaged drainpipe, however, will require more extensive repair work. Since sewer gas can pose a direct danger to occupants, you should evacuate the premises until the plumber has fixed the toilet and allowed the home to air out. You should also take care not to light any fires or create any sparks that might cause an explosion.