Horizontal Vent Pipe In Attic

There will be approximately 4 of attic above the peak of the cathedral ceiling.

Horizontal vent pipe in attic.

Ran across this situation today on a warranty inspection. With horizontal venting you must follow specific guidelines to ensure proper venting. Horizontal venting in horizontal vent systems the vent pipe can slope away or toward the water heater. In many an older home this drain pipe is perhaps 4 inches in diameter and stays that size all the way through the roof.

This allows flue gases to gain upward momentum before encountering restrictions. Another not so common way the vent can become clogged is when a horizontal section of the venting system itself inside the attic is sloped the wrong way. The vent runs horizontal for 20 25 feet across the attic to the vertical pipe that goes through the roof. The top plate may be doubled meaning you have to drill through 3 inches.

Most manufacturers suggest at least 12 inches of vertical run from the stove. A full sized vent is a primary vent where the drain line transitions at some point and becomes the vent pipe that exits the roof. Other vent pipes that are smaller may connect to this full sized vent and that s perfectly fine. You may need to move the hole over a few inches.

They can attach right behind your fixture or horizontally to the drain line. Re vent pipes otherwise known as auxiliary vents attach to the drain line near your fixture as they run upwards and over the main vent. Experienced home inspectors should be on the look out for these conditions. To run a vent pipe through the ceiling first drill a test hole to make sure you won t bump into any joists in the attic.

When that happens it can fill with rain water or condensation.