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Community and Q&A

Airtight floor drain assembly?

Dylan Kinsey | Posted in Energy Efficiency and Durability on

Hey There Fellow Tradesman,

Wondering if anyone out there has discovered a good trick for dealing with basement floor drains in airtight homes. Typically, a standard P trap isn’t recommended for floor drains as they’re prone to filling with floor sweepings and difficult to clean out.
I hate the idea of air pouring into the basement every time the wind blows, or the range hood is used. Anyone found a good product or strategy for dealing with this?


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  1. GBA Editor
    Martin Holladay | | #1

    Conventional floor drains usually include a trap. If the water in the trap isn't allowed to evaporate -- if you pour a little water down the drain occasionally -- then the drain shouldn't allow air to enter the house.

    A company called Dranjer sells a variety of floor drains designed for basements with active radon mitigation systems; they are designed for airtight installations, so you may want to call Dranjer to see if they have something that suits you. Here is a link to a relevant web page: Dranjer floor drains.

    Dranjer Corporation
    9 - 10 McGillivray Place
    Winnipeg, Manitoba R3T 1N4

  2. Dylan Kinsey | | #2


    Agreed. A trap would be fine and would likely stay hydrated by a condensate line from a heat pump water heater. Should be enough water.
    I'll check out the link. Thanks for the heads-up!

  3. Rich M | | #3

    Look for a Bell Trap floor drain. These have a circular moat in the base and the strainer has a circular flange that sits into this moat. Just lift the strainer to clean the bell trap. A plumber we used many years ago said they poured vegetable oil into the trap in commercial buildings if they were seldom used and the water was evaporating. There are also check valves to prevent back flow.

  4. Dylan Kinsey | | #4

    That's probably what I'll end up doing. I'd been holding out for some really groovy new product that performs a little better, but alas....simple is better. Thanks Rich!

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