Basement Rim Joist Spray Foam Project in Ypsilanti, MI

We weren’t even looking at the rim joists at first
One thing I’ve noticed over the years is that homeowners will describe a problem one way, and then when we actually get into the house, it’s something completely different.
That happened on this job in Ypsilanti.
The homeowner kept mentioning rooms that just never seemed comfortable. Not terrible. Just…off. One room would feel fine and another wouldn’t. Michigan winters have a way of exposing every little weakness in a house, so they wanted us to take a look.
I’ll be honest, I thought we’d end up talking more about attic insulation.
We didn’t.
Once the fiberglass came out, it made a lot more sense
The basement rim joists were insulated with fiberglass batt insulation. Pretty common.
And for a second, standing there looking at it, I thought it looked okay.
Then we started pulling it down.
Different story.
You could actually feel little pockets of cooler air around sections of the perimeter. Nothing dramatic. No movie-style wind blowing through the basement. Just enough that you notice it when you’re standing there for a while.
The basement was cool that morning too. Concrete floors. Slight damp smell. Typical Michigan basement.
The homeowner said something that stuck with me
At one point the homeowner laughed and said,
“I’ve probably spent more money replacing weatherstripping than I needed to.”
Maybe.
Maybe not.
But I understood what they meant.
A lot of people automatically blame windows and doors. Sometimes they’re right. Sometimes they’re chasing the wrong thing for years.
This isn’t the flashy part of a house
Nobody shows off their rim joists.
Nobody has friends over and says, “Come look at my basement perimeter.”
That’s not how this works.
But these areas matter more than most people realize. Actually, scratch that. I said I wasn’t going to turn this into one of those educational articles.
What I mean is we’ve done enough houses around Ypsilanti and Ann Arbor to know that when these areas aren’t sealed well, we usually find ourselves talking about comfort complaints somewhere else in the house too.
Not always.
A lot of the time though.
Spray foam just made sense here
We ended up removing all the old fiberglass around the perimeter and installing about 2.5 inches of closed-cell spray foam along roughly 172 linear feet of rim joist area.
Some sections were easy.
Some weren’t.
There’s always one spot that’s tucked behind something or buried in a corner that makes you stop and think for a minute.
That was it.
We used other sealing materials in a few hard-to-reach areas to make sure everything stayed continuous.
A quick side thought
I don’t know why basements always seem to become storage museums.
Every basement has something.
Old paint cans. Holiday decorations. Furniture nobody wants to throw away.
This one had a treadmill that looked newer than the one at my gym.
Anyway…
The house should feel different now
By the end of the day everything was cleaned up, photos were taken, and the homeowner had a completely sealed rim joist system instead of aging fiberglass that wasn’t doing much anymore.
Will they walk into the house tomorrow and think, “Wow, my rim joists look amazing?”
Probably not.
But when winter rolls around and the house feels more consistent from room to room, that’s usually when these projects start making sense to people.
We also included our annual insulation inspection so we can keep an eye on things moving forward. If you’re in Ypsilanti, Ann Arbor, or anywhere nearby and you’ve been dealing with rooms that just never seem quite right, give Koala Insulation of Greater Ann Arbor a call or visit our website for a FREE evaluation.