why does my house smell after rain

Donnie Hartley
by Donnie Hartley
Every time it rains a downpour my house smells like sewer
  3 answers
  • There can be several reasons for this. The first thing I would look into is your drainage system. You did not mention what type of sewer connection you have if its a septic system or a city one. There can be backups in the drain system that can be back venting into your fixtures or drain pipes located in the basement. Normally there is a U trap located just near the basement wall or just outside the house. This trap is to prevent sewer gasses from backing up into the house. During rains the city drains can over fill and cause the city sewage to back flow into and past the trap. This can result I gasses entering into basement sinks, toilet etc. Another reason can be from a leak that occurs due to the rain. This activates a prior mold issue that may be hidden and only its odor can be smelled when it gets damp. To help you out a bit more, tell us more about the house. Age, type, colonial, ranch? What about basement, slab, crawl space? Type of sewer system, city or is it a septic or cesspool? Type of drain system. Cast iron or plastic. If there is a basement, what fixtures are located in that area? Shower, toilet, slop sink? Sump pump? Were does the odor appear the worst? Basement, living area?
    • Donnie Hartley Donnie Hartley on Sep 14, 2014
      @Woodbridge Environmental Tiptophouse.com Thanks for replying to my question. My house is a 15 year old Cape cod style modular home with a septic tank and a crawlspace. The smell is in every room with a drain but only for a few minutes during and a little after a downpour or days of rain. Thx again for any input.
  • Sherrie Sherrie on Sep 14, 2014
    We don't have a basement and had to put sub pumps underneath our house, it also smelled terrible
  • Sounds as though your having a venting issue. Or the septic system is backing up. When was the last time you had it pumped out. Most health departments suggest every three years to five at most. But odors come up from vents. This is the reason why there are traps under the sinks, toilets, showers and tubs. Normally the traps dry out in basements from lack of use which causes the odor to seep into the home. But if its coming into rooms that have sinks etc. then there is an issue with venting. Perhaps the main vent on the roof is plugged? This would be the first thing I would check. Also when you flush toilets after they sit for a half hour or so, do you get a gurgling sound or a blub blub sound in the sinks. This is often a sign of a venting issue. The only way for odors other then simply leaching into the rooms from the crawl is the vents in the sinks, called the overflow drain. There is also one on the tub. Have you sniffed in the crawl space to see if there is any issues there. Back ups from septic systems can flood the crawl space as most of the plumbing is very near the level of the tank. If during heavy rains the leach field fills and backflows into the septic this in turn can back up the sewage into the crawl space.