2026-01-26 – Weekly Plumbing News : Who actually invented the P-trap?

Last week, our forum saw lively discussions around practical challenges and industry trends. Members dived into code compliance issues and shared techniques for improving inspection results. There was also a focus on skill development, with conversations about training for camera and locator equipment. The community engaged with historical debates and practical energy-saving tips, making it a week rich in both technical and professional growth.


This Week’s Hot Topics

Blueprint says 1/8, code says nope
This discussion tackles the frequent discrepancies between blueprints and code requirements, a common headache for many in the field. It’s worth a look if you’ve ever had to reconcile these differences.
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CE that improves inspection outcomes
Here, members share continuing education courses that have genuinely enhanced their inspection skills. It’s a great thread for those looking to boost their expertise.
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Worthwhile camera and locator training
If you’re considering skills enhancement, this thread explores the value of training programs for camera and locator use. It’s practical advice from those who’ve been there.
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Left-handed wrench at dawn
A light-hearted yet informative exploration of the left-handed wrench myth. It’s a fun read that also touches on tool ergonomics.
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Who actually invented the P-trap
Dive into a historical debate over the origins of the P-trap. This thread offers a fascinating look at plumbing history and its impact on modern practices.
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Quick checks for water heater energy waste
Members share quick tips to identify and reduce energy waste in water heaters. It’s practical, everyday advice that could lead to significant savings.
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Cutting pump energy without losing pressure
This thread discusses strategies to reduce energy use in pumps without sacrificing performance. It’s a must-read for those looking to improve efficiency.
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Finding allies on the job site
Explore the importance of building relationships on site and how it can improve workflow and morale. This discussion is packed with personal stories and practical tips.
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Hammer arrestors at laundry boxes
A technical discussion on the necessity of hammer arrestors in laundry setups. This could be crucial information if you’re working in residential plumbing.
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Thanks for staying connected with our community. Whether you’re sharing your expertise or picking up new skills, your involvement makes a difference. Until next time, keep the conversations flowing.

Debate aside, inspectors only care that it’s a proper P-trap and vented — S-traps still get flagged in 2026; i keep a 1–1/2 in. trap kit and an AAV in the van to convert old vanities on the spot; 15 minutes and you save the re-inspection. @Maya are AAVs getting approved on single lavs your way, or still a hard no?

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And pretty sure the water-seal started with Cumming’s 1775 S-bend, and Crapper’s later U-bend is the ancestor of the modern P-trap: Trap (plumbing) - Wikipedia. , in tight vanity swaps I use a deep-seal 1–1/2 in P-trap with a cleanout tee so inspections and those camera-training checks the OP mentioned go smoother. If clearance is brutal, a low-profile tubular set works, but I worry about shallow seals — anyone had issues with nuisance siphon on those?

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Speaking of P-traps, I’ve found that using a deeper trap can help prevent odors from escaping, especially in tight spaces like vanities. They often require a bit more space, but it’s worth it to avoid those stinky surprises down the line. How do you all manage venting in those tighter setups?

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