PREVent Roof Vent Leaking

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SUIET Hacks removed a closet rear-panel when trying to remove Hymer's "factory installed" butane torch (a story for another time). We were disappointed to see sunlight around the plumbing vent pipe's exit through the ProMaster's metal roof. There were a number of design root causes:

1. The hole drilled in the roof was almost the same diameter as the "nut" covering the hole in roof.
2. The external "nut" and interior flange were both rigid plastic with no gasket to give compliance to the rough cut metal.
3. The ceiling and vent pipe were misaligned causing the pipe to exit the roof at an angle.
4. The silicon applied to the gaps was too weak to stop the poorly secured pipe from shifting in the roof hole.
5. The un-screened hole lets bugs in the grey water tank, and up the sink and shower drains. Have you ever seen the number of cockroaches living in city sanitary sewer systems? Disgusting.

Footnote: After posting this hack a newer Aktiv was seen with putty around the "nut", picture 6. This is far better than what Hymer shipped on SUIET. SUIET Hacks worries that the small surface hard plastic nut doesn't provide a secure mechanical connection so the pipe will move, the putty will come loose and leak.

This project's Installation takes about 20 minutes and costs less than $10 including the optional screen. Home Depot didn't stock a large diameter stainless steel washer and gasket that would fit under Hymer's "nut." The gasket needs a stainless cover to protect it from the sun so we picked a 1-1/2 in. x 2 in. rubber stainless steel shielded coupling to be the "nut," gasket and cover. The wide rubber surface on the 1-1/2 inch side of the coupling provides an excellent gasket against the roof. The shield assures a tight long-lasting sun-free connection.

Special Tools:

• Step ladder to safely work at roof height

Parts (picture 3)

• 1-1/2 in. x 2 in. rubber shielded coupling (e.g., Home Depot SKU 482124)
• Weatherproof window and flashing silicone (not bathroom silicone)
• Optional screen: 2.5 inch lavatory sink strainer (Home Depot SKU 645741) and 2 inch x 2 ft. ABS schedule 40 pipe (Home Depot SKU 372813)

Installation (picture 5)

• Remove the cabinet rear panel up un-snaping the four screw covers and removing four screws (See picture 4)
• Remove existing exterior vent "nut."
• Inspect for metal burrs and rust in the roof. File and paint if needed.
• Loosen interior vent coupling and saw ceiling panel if needed to have the vent pipe exit the roof vertically. Pull the pipe and coupling vertically so the pipe flange is against the roof.
• Re-tighten the vent coupling.
• Liberally apply silicone to the external vent pipe threads, flange and roof.
• Slide the 1-1/2" side of the shielded coupling over the vent pipe threads and tighten the lower shield band until the rubber grabs the vent pipe threads.
• Turn the coupling clockwise and tighten it firmly so the vent pipe is pulled tightly to the interior and the coupling is tight against the roof. A helper holding the pipe inside may be needed.
• Fully tighten the lower shield band.
• Reinstall cabinet panel.
• OPTIONAL SCREEN
• Cut two 1/4-inch "rings" of 2-inch ABS pipe.
• Put one ring in the 2-inch coupling side to form a stop.
• Apply a liberal ring of silicon on top of the ABS ring inside the coupling.
• Put strainer in as shown (face up so it doesn't collect leaves and clog the vent).
• Put the second ring over strainer and press down firmly.
• Tighten the upper shield ring.
• Done.