Exterior Insulation on Cinder Block Walls
I have been through many articles talking about exterior insulation techniques, and insulating the exterior of foundations. My house is a little unique, and I’m hoping that someone can offer some insights/guidelines on how to handle things.
First of all, I live in mid-Vermont (climate zone 6A). I bought my first house last year, and the siding needs some work in addition to not being my favorite style. A project I’d like to do at some point within the next couple years would be to remove the old siding, insulate the exterior, and then install new siding. The new siding I’m looking into is a product from Shakertown, which are convenient cedar shingle panels with a built in rainscreen as part of the backing.
The house is built into a hill, so the hillside (rear) half is only one story tall, with the front half being a 2-story walk out basement style. It was built in 1950 and it’s exterior walls are entirely cinder block (the unique/unusual part) from the base of the foundation all the way up to meet the roofing system.
This is where my grey-area begins, since all the information I’ve been able to find about exterior insulation combined with siding assume a stud wall + sheathing construction as the exterior wall.
I’m hoping to find suggestions on how the system should be laid out, starting at the cinder blocks and working outwards. Some specific questions I have include:
- I’ve read the house wrap can go in front or behind the insulation. In this case though, where does house wrap get applied? I assume on top of the insulation, because how would you attach it to the cinder blocks…but then how do you attach house wrap directly to insulation?
- Given the age of the house, and from what I’ve seen I’m inclined to assume the cinder blocks are hollow. I’m concerned about using a fastener that is “shot” in. Are there suggestions for a “gentler” style fastener?
- After finding the appropriate anchors to attach the insulation, I’d like to apply it in a continuous fashion, which leaves attaching strapping over the insulation as my option for how to attach the siding. Keeping in mind the “gentle” fasteners, how would I attach the strapping to the house?
Thanks again for taking the time to read my post, and I appreciate any suggestions or feedback I might receive. Any musings about how the layers should stack up in this wall system are welcome.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part