How to insulate rim joists & above grade basement walls in older home without using foam?
I’d appreciate input on how best to insulate/air seal an older basement without using foam (rigid or spray). I’ve gotten input from a few several weatherization folks, but the information varies and seems pretty expensive. I’m looking for an affordable solution that will work. (Photos are attached).
My goal is to 1) air seal and insulate the rim joists, 2) air seal the above-grade brick. I will eventually insulate the brick when budget allows.
RIM JOISTS: One plan is to either caulk or use Eco-seal spray applied sealant to air seal the joist cavities, then insert mineral wool (Roxul). Does the mineral wool need to be covered? I talked to 475 and they suggested using Intello, but the material is expensive and the labor will probably be expensive, too.
ABOVE GRADE BRICK: The above grade brick is about 4 ft tall. The exterior has decorative rock applied on 3 sides of the house (see photo) and I want to keep that look so any air-sealing solution would have to be on the interior. The mortar joints have holes of varying sizes so I’d like to air seal to start with. I don’t think it’s a structural issue. Also, the brick looks like it’s been painted white, if that has any bearing.
One contractor suggested troweling on Quickrete Surface Bond (with fiberglass) and the Q rep agreed. However, a mason I spoke to said to avoid products like that with Portland cement and instead use lime (NHL) or clay based mortar. I’ve seen basements that have had some time of parging and it’s crumbing and flaking off. I want to avoid that.
Someone else used Tu-Tuf to line the joist bays and then follow down the basement wall. He placed Eco-cell (rigid cellulose) batts on top of that, securing them with an adhesive and some strapping. Not sure if this is a tried & tested approach, but would like to hear if anyone has experience with either of these methods.
Below grade foundation is large stone. There are no water issues in the basement, but it does have a musty smell so I run a dehumidifier. The house was built in 1908 and all the rim joists and framing are in great shape, no rot. I’d like to keep it that way. When I had a blower door test done, there were low numbers when the door to the basement was closed, but as soon as we opened it, the numbers almost doubled so I know air sealing is needed!
Thanks in advance for any insights or experience in doing this.
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