Insulation basement projects commonly get skipped or just use fiberglass batts. Unfortunately, there’s major problems with both scenarios.
Both cellulose and spray foam insulation on the basement walls will keep the area comfortable and safe all year round. Which is the most efficient and effective choice depends on the situation.
Moisture is the Problem
Concrete foundation wall insulation is exposed to far more moisture than in other areas of the home, and fiberglass is irrevocably damaged by moisture. This means what insulation insulation quality there was degrades quickly. Since uninsulated basements get too cold in the winter, finished basements tend to be rarely used and are prone to mold.
The Best Basement Insulation
The Most Recommended Option
For Basement Walls and Box Sills
Walls: Cellulose costs less than fiberglass when factoring in heating bills and manages moisture far better.
Box Sills: The key here is air sealing, and spray foam insulation also air seals exceptionally well.
Basement Wall Insulation
Similar to Other Walls
Not insulating basement walls in northern climates typically results in not using the basement for half the year.
Basement Ceiling Insulation
Sound and Floor Warmth
The 2 most common reasons home owners insulate basement ceilings is for sound control and to warm up the floor above. Depending on furnace vent location, this may cause the basement to grow colder. Insulating basement walls will warm both the basement and floor above.
More on Box Sills
Critical Air Sealing Area
The gaps above the basement walls between the boards holding up the floor above are called box sills. You can see them in any unfinished (un-drywalled) basement. They are by far the leakiest part of most homes, and together equate to a year-round open window in the basement.
Types of Insulation
A Big Difference
No matter the location, insulation type plays a big role in results. We go into detail about the 3 common insulation types in this article.
Insulation Types at a Glance
Spray foam sticks to surfaces, so there’s no need to build a retaining wall to hold the insulation in. It also can be used on the crawlspace ceiling (if that is a better option) and removes the need for the vapor barrier that could fall down (spray foam is a vapor barrier and never falls off). Finally, it is immune to moisture damage, and crawl spaces are notoriously humid.
Diminishing returns. It’s the sweet where most of the heat transfer is prevented without running up the project costs. See exterior walls for more details.
A Single Best Solution
Most people insulate crawlspaces to warm the floor above them. While insulating that floor seems obvious, it’s almost always better to insulate the crawlspace walls instead. It’s less expensive and equally effective.
State Rebates & Incentives
Many (though not all) Wisconsin insulation projects are eligible for hundreds of dollars in rebates through the state’s Department of Energy. We typically capture at least 1 rebate per week for our clients.
We are certified to implement these rebates and complete nearly all the paperwork for you. We even instantly discount the rebate from your invoice, so you’re not left waiting for the rebate check to arrive.
Know YOUR Numbers
Planning with general numbers often leads to inaccurate estimations and budgets. That’s one of the many reasons we offer free estimates. Whether you need a quick fix or are planning for work next year, work with actual numbers specific to you.