Walk into most attics in the Chippewa Valley and you'll find the same thing: 6 to 8 inches of fiberglass batts — maybe blown-in cellulose if someone upgraded at some point — sitting between the joists and not covering them. That was code-compliant when the house was built. It's nowhere close to current standards.
Today's Wisconsin energy code calls for R-49 in attics. Most homes built before 2000 have R-19 to R-30 at best. That gap is costing you real money every month.
The Math on Heat Loss
Heat rises. Your attic is the #1 escape route for the heated air you're paying for all winter. Going from R-19 to R-49 in an attic can reduce your heating energy loss through the ceiling by 50–60%. On a typical Eau Claire home, that translates to $300–$600 per year in heating savings — which means the upgrade often pays for itself in 3–5 years.
It's Not Just About Winter
Under-insulated attics don't just cost you in winter. In July, that 140°F attic is radiating heat down into your living space, making your AC work overtime. Proper insulation keeps the temperature differential manageable year-round.
Ice Dams: The Visible Symptom
If you get ice dams every winter, that's your roof telling you the attic insulation is inadequate. Heat escaping through the attic floor warms the roof deck, melting snow from underneath. That meltwater runs down to the cold eaves and refreezes, creating dams that force water back under your shingles. The fix isn't removing ice dams — it's fixing the insulation and air sealing so they don't form in the first place.
Air Sealing: The Hidden Half
Insulation alone doesn't solve the problem. Your attic has dozens of penetrations — electrical boxes, plumbing vents, recessed lights, the chimney chase, attic hatches — and every one of them leaks conditioned air into the attic. Air sealing these penetrations before adding insulation is critical. Without it, warm air convects right through the insulation and you lose most of the benefit.
This is where a lot of DIY insulation jobs fall short. Adding another 10 inches of blown-in on top of existing batts helps, but if you haven't sealed the bypass paths underneath, you're insulating a leaky bucket.
What About Walls and Rim Joists?
Attics get the most attention because they're the easiest to access and the highest-impact fix. But rim joists (where the floor framing meets the foundation wall) are often completely uninsulated and are a major source of cold drafts in basements. Spray foam on rim joists is one of the most cost-effective insulation upgrades you can make.
Wall insulation is trickier on existing homes since you'd need to open the walls or drill-and-fill. It's worth doing during a siding replacement project when the sheathing is already exposed — that's the most practical and cost-effective window to add wall insulation.
What Does It Cost?
For a typical 1,200-square-foot attic in the Eau Claire area:
- Air sealing + blown-in insulation to R-49: $2,500–$4,500
- Rim joist spray foam: $800–$1,500
- Full attic spray foam (cathedral ceilings): $5,000–$9,000
Focus Wisconsin and other utility programs sometimes offer rebates for insulation upgrades. We can help you check what's currently available.
How to Check Your Insulation
If you have attic access, take a look. If you can see the tops of the ceiling joists, you don't have enough insulation — it should be well above them. If the insulation is uneven, compressed, or has gaps, it's not performing at rated value.
We do free insulation assessments. We'll measure what you have, identify air leakage paths, and tell you exactly what it would take to bring your home up to current performance standards. Schedule yours here.