Air sealing and insulation upgrades before major renovation?
dustindawind
| Posted in Energy Efficiency and Durability on
We are in early stages of planning a significant renovation (including potential small addition), which is realistically 2+ years away. Is there any reason to not do air sealing and insulation retrofits on our circa 1900 home now?
Some conditions to consider:
– Rim joist is uninsulated
– Little wall insulation
– Attic floor and basement ceiling insulation is degraded and thin
– Exterior board sheathing has no wrap (beyond that is degraded wood shingles, 1/2 inch board, and vinyl exterior)
My concern is whether any upgrades will significantly hinder/impact/add to cost of the future renovation.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Any upgrades that would be "in the way" would add cost to your renovation, because you'd have to redo them. What you want to do is do any insulating and air sealing upgrades in the area of your renovation/addition at the time that work is done, since it's much easier to open the wall up once and do everything.
For the basement, rip out the old ceiling insulation and insulate the walls instead. Rigid foam is the way to go here, and there is a lot of info on this site about how to do it. Rim joist insulation can probably be done (at least most of it) before your renovation/addition, since it's probably not going to be in the way of the future work you'll be doing. There are several ways to do this work too, all of which are covered on this site.
Attic insulation could potentially be done now, if you won't be working in the attic during your future projects. You would normally remove the old insulation, air seal the attic floor (lots of info here about that), then add new insulation, typically to at least R49 in most climate zones, sometimes R60. Loose fill (blown) cellulose is the preferred material to use here in most cases.
Wall insulation and air sealing is probably best done when you're doing the other renovation and addition work, since that's when you're likely to have the walls open anyway. You have to open at least one side (interior or exterior) of the walls to really do a good job here. If you're going to reside the house during your renovation work, that's a good time to consider putting up exterior rigid foam for a BIG improvement in overall insulation on those walls.
There are some low hanging fruit areas you can try airsealing too, which would be the classic leaky spots like wire and pipe penetrations, recessed can lights, attic hatches, etc. A lot of that could probably be done now too.
Bill