Roof Penetrations

I went back and forth and hemmed and hawed when it came to how to vent the bathrooms. I was concerned that on the second floor, if I went out the side it would be right underneath the gutters, and picturing steamy air in the middle of winter was just not a good mental picture. At the same time, going straight up is yet another roof penetration, places that can leak if not today then eventually. I was committed to the roof to the point of ordering some roof caps, only to briefly plan to run PVC pipe and then finally going back to out the side.

It came down to the slope of the pipe. When water condenses in the exhaust pipe, I want it to drain out not back into the bathroom. Since I plan to run the venting in PVC, which will never rust or leak and doesn’t require nearly as much insulation to prevent condensing on the wrong side, angling it down to the outside is a nice, short run. I made my peace with the vent under the gutter by buying the downward-sloping metal vents rather than the flat louvered plastic things.

I also spent a lot of time figuring out the exhaust fan for the kitchen. This time, the roof was pretty much the only option. Because we plan to have a, ahem, large range, we need a big exhaust fan (plus some kind of makeup air). The required 6″ ducting could easily go straight out the side, but it would spew greasy smoke directly across from the neighbor’s window, about three feet away. Dean suggested I go out the side in the other direction, so we took a gander at the other neighbor, and sure enough they have a window there too. So, up it is. I debated the style of roof exhaust too, concerning myself with snow accumulation, grease on my shingles, you name it, but ultimately I decided to just put the damn thing I’d already ordered in the roof and commit.

Sarah in the attic

Cutting the hole

Kitchen exhaust cap

That still left some big projects. We vented the water heater out the side of the house, and every winter it frosts over because it’s right next to the exhaust for the boiler, and every summer Sarah complains that it smells between the houses when it runs, most likely because it’s condensing, so the exhaust isn’t hot enough to float away right away. The solution: run it up and out the roof. The challenge was there wasn’t a particularly direct way to do that. Exceeding a handful of elbows meant I needed to step up from 2″ to 3″ PVC for both the intake and exhaust lines, which had to run parallel the whole way until the combine in a concentric vent just before going out the roof.

Fun parallel bends

Concentric cap on roof

Dean saved the day, throwing ideas at me on how to route it until we finally coalesced into a plan. We spent most of the day in the basement, cutting holes in the joists (center third vertically, outer third horizontally) to run the pipes along the outside wall to get to the wet wall, so they could then run up to the attic before jogging over about six feet to get enough clearance from the other vents. I got the flashing boot onto the pipe, managing to knock the cap of the concentric vent off in the process. It bounced off the neighbor’s roof before it fell to the ground and cracked. I glued the thing back together with PVC cement, so it now has purple primer crack lines, but it’s installed.

Template for cutting

Then there was light!

Base installed

Finally, the largest holes of all were the two solar tubes. We’d trimmed down our original plans to one solar tube in the master bedroom closet and one big solar tube that goes through the attic and second floor to bring light all the way to the kitchen and living room on the first floor. We cut the holes from the inside, then Sarah tied a rope around the flashing base so I could hoist them up and put them in position. It wasn’t the cleanest of jobs, but since the roof is about to be replaced, they’re mostly there so the roofer know where they go. They can attach them more permanently. Sorry I don’t have completed pictures of the solar tubes, I was more concerned about getting down safely.