Another old-house-with-no-sheathing question
mdesloge
| Posted in Energy Efficiency and Durability on
I’m in climate zone 2, with a 1910 bungalow with dutchlap siding directly over the studs. If I was to do a gut rehab, I might remove the siding, install zip sheathing and rainscreen and re-side with cement fiber or something. Probably blown in insulation. I’m thinking a little lower on the $$$ scale, and wondered about just treating the current siding as sheathing, adding tyvek, and then re-siding. The siding is pretty flat, so siding over it wouldn’t be *too* bad (actually wondering about vinyl vs cement board). It’s a rental in a historic district, so I’m hoping to get it buttoned up for another decade or two.
thanks!
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Replies
The key with any energy retrofit is air sealing. It is possible to detail standard house wrap as an air barrier but very hard.
They way I've worked with t&g or board sheathing is by covering it with a peel and stick membrane (ie VP100). You can then install your siding directly over it. Vynil can be installed directly as it is self ventic, cemet or wood siding should be installed over a rain screen.
All siding will last for a couple of decades, mostly comes down to cost and preference. Being in a historic district will also limit your choices.
Along with air sealing, when you are redoing the siding is the time to add insulation to the walls. Even if there are crummy old fiberglass batts, dense packing over them will raise the R value of the wall and significantly reduce air leakage.
Make sure that you deal with your window flashing details as these tend to be non-existent on old houses. Water leaks means moldy insulation down the road.