Airtighting a drain to daylight?
harrison55
| Posted in Green Building Techniques on
We are building a reasonably airtight house.
We plan to install a floor drain with the discharge set up as drain-to-daylight. I am concerned the the trap might not always have water in it, which would create an air leak.
Is there a practical way to achieve a reliable air barrier for this drain? (I am thinking of something like a spring-loaded flapper valve at the daylight end . . . )
Suggestions?
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Replies
Mark,
Several companies sell a back-flow preventer that works as you describe. One is the (unfortunately named) Rectorseal:
https://www.rectorseal.com/sureseal-trap-seal/
Self priming traps are available that periodically introduce a small amount of water into the trap.
Douglas Higden
Our drains to daylight don't have P traps. Not exactly sure why, but I had the same concern with our 3 garage drains to daylight. I used these https://www.amazon.com/gp/product/B00W2FQX2U/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 which are similar to the "Sure Seal" product above. We aren't living in our house yet, so I can't speak to their effectiveness, but it appears they will work well.
Scott,
P-traps are typically used on drains connected to sewer systems to stop gas from venting into the house. Floor drains to daylight often don't have P-traps, although it's a good idea both to stop pests using it as an entry point, and for air-sealing where that matters.