Installing Exterior Insulation
I am trying to add exterior insulation to a Chicago Home (zone 5). I’ve read several articles here and I think I have a fair understanding on how to rebuild the walls, but I have some questions…..
My main issue as far as I can tell is that currently I have either a thin layer of foam between my vinyl siding and sheathing or in some areas nothing at all. I do not believe I have any interior poly.
My plan so far is to remove siding and current layer of foam. Tape the seams of the sheathing, Add tyvek WRB (tape the seams), one layer of Roxul comfort board 80 (R-6), 1×4 furring strips and then vinyl siding again.
1). As you can see in the attached pictures; the siding comes up to the soffit. If I add extra thickness to the wall there will be an overlap with the soffit. Is this an issue? If so are there any recommended fixes? Should I just have the soffits removed and re-done?
2). You can also see that the siding comes up to a brick wall. Similar issue. With the extra thickness there will be an overlap though I am assuming this joint could just be caulked…
3). At some point I will need to re-do the roof. I plan on adding 4” polyiso on top of the roof when I decide to tackle that. I have read pros and cons on installing a water and ice shield. I have seen some videos where the rafter tails are removed and a peel and stick (I’m assuming the shield) is folded over onto the wall. I think over the WRB? Is this advisable? I have some concerns using a shield given its impermeable nature but I also have significant issues with ice dams… If the shield needs to be folded onto the WRB then it would seem necessary to do this before the wall….
Thanks in advance to anyone that can help answer my questions. This site has been very helpful.
Faisal
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Replies
Faisal,
Not sure if you've already done this or not, but you'll likely want to redo the soffits, especially if there are vents in it, to make sure they aren't being covered up. For the the connection to the brick, I would use a fluid-applied membrane (like a prosoco or zip) to continue the seal from the tyvek to the brick. Remember when you attach the vinyl siding that the nails should not be driven all the way in - the siding needs to move as it expands and contracts.
Best of luck,
Mike
You are proposing extensive work for siding that looks to be in good shape.
What issue are you trying to solve for? Will the cost reap an associated benefit?
If this is a comfort issue, consider massive air sealing approached from the interior.