{"id":33,"date":"2025-09-23T04:52:55","date_gmt":"2025-09-23T09:52:55","guid":{"rendered":"https:\/\/plumbing101.i234.me\/wordpress\/?p=33"},"modified":"2025-09-23T04:52:55","modified_gmt":"2025-09-23T09:52:55","slug":"basement-bath-drains-simple-code-smart-layout","status":"publish","type":"post","link":"https:\/\/plumbing101.i234.me\/wordpress\/basement-bath-drains-simple-code-smart-layout\/","title":{"rendered":"Basement Bath Drains: Simple, Code-Smart Layout"},"content":{"rendered":"
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Basement Bath Drains: Simple, Code-Smart Layout<\/h1>\n

(plumbing101.i234.me)<\/a><\/strong><\/p>\n<\/header>\n

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Question<\/h2>\n

I am remodeling a bathroom with a shared kitchen stack.<\/p>\n

The lav and kitchen share a 2-inch line in the wall.<\/p>\n

A 2-inch branch under the floor serves the tub or shower.<\/p>\n

The toilet will sit over a 4-inch hub to the main drain.<\/p>\n

How should I route drains and vents for a clean layout?<\/p>\n

Where do cleanouts and transitions belong for inspection?<\/p>\n<\/section>\n

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Answer<\/h2>\n

Use the lavatory\u2019s 2-inch drain as the wet vent for the bathroom group. Keep the lav vent vertical to 6 inches above the highest flood rim before any horizontal run. Tie the tub\u2019s 2-inch trap arm into the lav drain with a combo wye and 45. Bring the toilet\u2019s 3-inch closet bend into the wet-vented line with a 3\u00d72 wye, then into the 4-inch building drain. Keep the kitchen sink off the wet-vented section. Revent it above the flood rims or tie it downstream on the building drain. Install a 3-inch end cleanout at the upstream end and a 2-inch cleanout at the base of the lav vent. Use a shielded transition coupling for any PVC-to-galvanized connection above ground. Maintain 1\/4 inch per foot slope on all horizontals.<\/strong><\/p>\n<\/section>\n

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Why this layout works<\/h2>\n