The vent has to go through the roof at some point. Period. It cannot run through a gable vent (Vent on side of house at the top where the two flat sections of roof form the peak). It can either go through the roof straight up, or, for aesthetic reasons, can be ducted over slightly (For instance so the vent protrusion is on the rear of the roof rather than the front face). Your gable vents are sized so that your attic receives proper ventilation and remains at ambient temperature. Decreasing the attic ventilation by running a 10" vent through the gable vent will result in higher attic temperatures during summer (higher utility bills for you), shorter lifespan of your shingles, and a warmer than needed attic during winter leading to possible ice dams that will damage your roof.

My guess is that as long as it isn't directly underneath some huge point load (like a valley rafter or the jack studs of a large-headed opening above) the answer is "probably". If the framing was laid out neatly, there is another stud bay or rafter bay above the joist bay you're using. Make the hole as neatly as possible, try not to destroy the band. If you would feel better, add a vertical 2x4 leg on the flat to each side of the hole. This will support the bottom plate above you, and hopefully prevent the band from crushing under load. Casey

Howdy, sorry for not responding sooner. I guess I'm not configured to forward the email notices. In regards to opaone's comments: Not sure what you might mean by a "real hood", but if it's a restaurant quality super duper hood - then no. The kitchen is tiny and unless I blow out an exterior wall it'll stay that way. The current hood is a standard 30" affair; it's only redeeming qualities are the nifty LEDs I installed and the 7" exhaust going out the top. The presence of so many 90° bends is exactly why I'd like to make a direct shot to the roof. What a horrid design! In regards to Austin Air's comments: The 5" space will easily fit the 11" x 3" oval (6" equivalent) duct I was planning on using. The furnace space is sealed and takes its make-up/combustion air from vents leading to the attic, which is ventilated through soffit vents and a large roof-mounted mushroom. Kitchen make-up air is currently not too much of an issue as the house is a "leaker" - I have yet to replace all the aluminium windows and sliders, but will surely install a vent/control/device to address make-up if/when I go with the through-the-roof range vent. What I'm leaning towards now, after posting this and asking around, is having my furnace replaced before doing the modification. I don't want to go through the work and then have Mr./Mrs./Ms. City Inspector Man/Woman/Person question the duct passing through the furnace closet. Another advantage would be the additional physical space gained by replacing the 1970s dinosaur-air-heater with a modern high-efficiency unit. They're so small now!! If I had me a moneytree, I'd plop a horizontal unit in the attic and solve all kinds of issues.

Patricia and GN Builders, thank you both for such quick responses. Patricia - the bedroom does have an egress window, facing South, the bathroom fan would be facing East and yes run directly under the Deck. Great point on ventilation... I may just be overthinking this. GN Builders - Coming through the rim-joist and the deck ledger is my current and only plan indeed. Any specific Vent Caps you may recommend? I was looking for a metal one with a grate to protect from any potential "intruders". Thanks again!