MoPID post #6 for Sept 6th, 2022
Vent pipe repair
Again, I didn't get anything made today that is worth its own post, but I made progress on a few for upcoming posts. I kept meaning to get around to realigning the ground vent pipe at the back of Dogstar and today I finally did.
A lot of earth-sheltered houses use a pipe like this passing through the ground and coming out on the shady side as a cool air inlet. They are angled slightly upward toward the house for drainage, usually can be sealed off on the inside to contain heat, and screened off for critters. As the dirt settled around this one, the pipe dropped and the feedthrough at the inside of the house was no longer aligned. I considered initially excavating the pipe and packing/tamping gravel down underneath it, but the risk of damaging the plastic water-barrier was too high and it turned out there was a much simpler fix anyway.
The pipe had sunk by almost exactly one board width below the feedthrough, and simply swapping the two boards would put it in good alignment, make a difficult circular cut unnecessary, and remove the need to plug the previous round hole. The only saw I had that wouldn't puncture the plastic behind the wall was the one on my multitool... so it was slow going. The boards each had one long screw holding them to the posts from the outside, so they took some prying and persuading but it wasn't too bad. The screws did have to be hammered straight again for
reuse though.
Screens needed to be installed on both the inside and outside openings of the pipe as well. There was a torn window screen in the boneyard that I cut into smaller pieces and that worked out great. I drilled some small holes in the pipe, about a half inch back from the end to thread baling wire though and secure the screens in place.
The boards are currently just sitting without fasteners right now. A small cavity between the boards and the waterproofing layer opened up as the ground settled, so I would like to fill that in with
cob before securing everything. I then need to grab a nice-looking trim/support piece to cover the cuts in the board, maybe it can double as a mount for the stove flashing that normally lives there.
The ventilation was immediately much better through the building, I wish I hadn't procrastinated on this
project for so long!
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