Further Projects Imminent

Today we sent off the contract for some work on our roof. We're using The Twelfth Century Slate Roofing Company. They will be doing the following work:

-->Base flash (with copper) the main chimney (the one we just had rebuilt)
-->Replace twenty missing and broken slates (VT/NY purple)
-->Remove the aluminum ridge cap (it's corroding and pulling off) and replace with a copper ridge cap

If all is well with the weather, he will start on Monday! Amazing!

We're also hoping to have him put a hole in our roof. That sounds bad, but we need a hole so that the vent pipe that currently ends in the attic will actually go outside (where it should be). We're thinking that we might be able to attach the vent pipe ourselves; we just need him to peel off the slate and take care of the flashing around it on the outside of the roof. It seems like we just need to attach a length of pipe; we'll investigate further to see if this warrants a plumber.

But today, while looking around for info on the vent pipe issue, I found this piece of information from our friends at This Old House:

Another option, if codes in your area allow, is to cut off the secondary vents in the attic at least 6 inches above the ceiling insulation and cap each one with an air-admittance vent. This is a device with a diaphragm that allows air to enter the stack when water goes down the drain but doesn't allow sewer gases to escape into the house. Theoretically, you could eliminate roof penetrations entirely with these vents, but at the moment, the codes say that every plumbing system must have at least one stack that extends outdoors.

So we do have a sewer vent that vents outdoors (off the downstairs bathroom & out through the flat roof). Perhaps we don't need to cut that hole. Further investigation is warranted.

Here is some interesting information about these air admittance valves:

Air admittance valves (AAVs) are pressure-activated, one-way mechanical vents, used in a plumbing system to eliminate the need for conventional pipe venting and roof penetrations. A discharge of wastewater causes the AAV to open, releasing the vacuum and allowing air to enter plumbing vent pipe for proper drainage. Otherwise, the valve remains closed, preventing the escape of sewer gas and maintaining the trap seal. Using AAVs can significantly reduce the amount of venting materials needed in a plumbing system, increase plumbing labor efficiency, allow greater flexibility in the layout of plumbing fixtures, and reduce long-term maintenance problems associated with conventional vent stack roofing penetrations.

Wow! I think we just solved our problem. Thank you, Internet, for saving us a boatload of money and hassle!

Here's some more information on issues & solutions to plumbing vents:
This one has a nice diagram.
This discussion thread features the "controversy" over AAV's.