Siding update with insulation install – but no sheathing
New here, but have been trying to suck up the knowledge as best as possible. Im sure this is the first of several questions, so forgive me if Im not providing enough/the right info to get things started.
I own an old farmhouse, right on the 5A/6A climate border. Its a foursquare type, with a few additions tacked on the back of it. My questions focus on the main part of the house, since its mostly original everywhere. Build date is circa 1880, built with a mix of new/reclaimed timbers (based on beams in the basement).
There is currently wood clap siding that is in pretty poor shape (needs paint, many are cupped/warped/split, brittle when trying to nail them). So, I dont like the siding currently, but the rest of the original details are there and in great shape. I want to keep all those. First choice is to use fiber cement as a replacement, and there is the distant thought of vinyl also depending on costs.
Part of the reason that we are also considering siding replacement is that there is not any insulation in the walls, and in one part there are some bricks. (this weekend I just discovered there were not bricks in all the walls, which is a good thing!) I had a contractor out this week to give an estimate, and we also discovered that there is not any sheathing either, the claps are direct nailed to the studs.
So now for the actual questions.
I am looking for a siding option that doesnt require me to insulate externally, since I really dont want to mess with the reveal on the windows or play with any of that trim work. Can anyone advise on what would be the best bet for insulating? My first thought was to use some rigid foam board, cut it to fit in the stud bays, and then use expanding foam to air-seal it to the structure. Then I at least have an air barrier. I know fiberglass is really not an option because it will just filter the air as it whistles through the wall. Would it make sense to blow cellulose into the wall cavity as new siding goes up?
Im not sure if fiber cement can be hung without sheathing, and if not, any other thoughts on what to install?
Sorry for the dis-jointed nature of the question, but there are a lot of moving parts and pieces, and I guess many of them are still fluid.
Ultimately, I dont want to have to re-trim the windows, but want to do what I can to help the energy efficiency of my house. (More questions to come about the awesomeness in my attic).
Thanks in advance!
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