According to the plans this should be more than enough space to allow a horizontal vent to pass over the peak and meet up with the main vent in the rest of the house which has a higher roof peak.
Horizontal vent pipe in attic.
With horizontal venting you must follow specific guidelines to ensure proper venting.
Most manufacturers suggest at least 12 inches of vertical run from the stove.
Horizontal venting in horizontal vent systems the vent pipe can slope away or toward the water heater.
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.
In many an older home this drain pipe is perhaps 4 inches in diameter and stays that size all the way through the roof.
You may need to move the hole over a few inches.
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.
Ran across this situation today on a warranty inspection.
The vent runs horizontal for 20 25 feet across the attic to the vertical pipe that goes through the roof.
They can attach right behind your fixture or horizontally to the drain line.
There will be approximately 4 of attic above the peak of the cathedral ceiling.
You must start with a vertical run of stovepipe before making a 90 degree turn towards the wall.
If the vent pipe slopes away the drain port cap located where the pipe exits the water heater blower pipe coupling should stay in place and the slope has to have at least 1 8 inch per foot.
Other vent pipes that are smaller may connect to this full sized vent and that s perfectly fine.
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.
The top plate may be doubled meaning you have to drill through 3 inches.
When that happens it can fill with rain water or condensation.