Can I run plumbing vents horizontally or at a shallow angle?
Asked by Us3r1234!
I'm looking to clear some roof space for solar panels and have a main stack that currently runs vertically through the roof of my building. Is it possible to transition this stack to run horizontally or at a slight slope along the exterior of my house to reach a different area of the roof? I'm also wondering if there are any building codes that I need to consider with this setup. Thanks for your help!
Answers
Yes, you can run plumbing vents horizontally as long as you terminate them vertically through the roof. It's generally recommended to maintain a slope of about 1/8" per foot towards the fixtures to prevent any rainwater from pooling. Just make sure to avoid any low spots where water can collect.
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From a mechanical engineering perspective, plumbing vents don’t need to be sloped like drains do since they aren't meant to channel liquids. They serve as a vacuum breaker for sewer gases. However, keep in mind that there are regulations on the maximum distance you can run a vent, so double-check your local building codes to stay compliant.
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I've moved vents for my solar project too! Ideally, you want to keep your vents around a 45-degree angle or steeper to avoid any water flow issues. Remember, vents are designed to allow sewer gases to escape, not to carry liquid like drain pipes, so having a significant slope isn't necessary. Just make sure that any water that enters doesn't collect or block the vent flow.
RoofExpert88: Good point! So basically, as long as the vent isn't totally flat, I should be fine?
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User_5678: What if I want to run it almost flat? Is that still okay?