We recently moved into an old double-wide trailer with several lean two additions. When we use the bathroom it starts to smell and one of the additions (mud room) that houses the washer and dryer begins to smell pretty bad as well. I traced the plumbing beneath the house and found a couple of issues. 1. There is no P-Trap from the washing machine. 2. After the P-Trap from the sink in the bathroom the drain line goes up hill towards the waste stack. Which brings me to the third and most scary issue. There are no venting pipes from the sinks, bathtub, or the waste stack. There is one vent that goes through the roof that comes from a drain line but this vent has several elbows before it finally vents. Can everything vent through this ? Help!!

Hi Mfranciosa

Are you sure there are no MECHANICAL VENTS (called AAVS) hidden behind any access panels or high up under the sinks? Check again to be sure.

Otherwise, one vent will act as a basic vent for the toilet/home, but it won't do much for the other individual fixtures.

Fix the washer drain and install a PTRAP and a mechanical vent as soon as possible.

Mark