Hi, I’m working on a 2-story, small single family residential design (climate zone 5) as a builder-owner, and we’re considering whether to pursue a 1h fire rated roof overhang to allow us a little more space to build on a very small lot. The overhang would extend by ~1ft into the 5 foot buffer zone (per 2018 code – https://codes.iccsafe.org/s/IRC2015/chapter-3-building-planning/IRC2015-Pt03-Ch03-SecR302.1) at the edge of the lot. We really wouldn’t be considering it but the whole lot is 33′ wide so even a foot helps. 

The issue is we’ll have a vented roof, R60 wool insulation, and originally wanted plenty of soffit vents to dry the underside of the roof plywood/OSB. (the one side that’ll need fire-rating is the bottom of the roof slope, so where a gutter would go.) But I can’t seem to figure out if a fire-rated soffit allows for such vents. Vulcan has fire-resistant eave vents: https://www.vulcanvents.com/vents/eave-vents/ but soffit vents don’t seem to be mentioned in the code (though gable vents are). 

This diagram shows a pretty similar situation with a 1h fire-rated overhang, and reprints the 2018 IRC table with relevant requirements. But it doesn’t mention vents: https://www.houstonpermittingcenter.org/media/6796/download?inline

One more thing in the code – “Roof eave fire-resistance rating shall be permitted to be reduced to 0 hours on the underside of the eave if fireblocking is provided from the wall top plate to the underside of the roof sheathing.” – however, this would block roof venting too, right?

Are there any other reasonable ways to vent a roof? Am I missing something? This only has to apply to one side of the house; the others need not be fire rated as they’re further from the lot line. We’re not in a wildfire area (east coast) for what it’s worth.

Of course we’ll accept if the best answer is we need to build further away to preserve the overhang! Or, perhaps I should just get really really good at wall waterproofing (we’re already doing a vented rain screen over Mento with few windows on this side) and make very minimal overhangs, as per this guidance: https://firesafemarin.org/harden-your-home/fire-resistant-soffits-eaves/

Thank you!