Your exterior remodel is well underway. The siding is being replaced, new windows are going in, and the updated look is starting to take shape. But before you close up those walls, there’s one crucial step that can’t be overlooked: properly reinsulating your exterior walls.
Reinsulating exterior walls during a remodel isn’t just about filling a cavity with insulation. It’s about protecting your investment, keeping your home comfortable, preventing moisture problems, and making sure your energy bills don’t skyrocket. Skipping this step can lead to hidden problems that are costly to fix later. At Terrapin Exteriors, we’ve seen too many homeowners underestimate the importance of exterior wall insulation, only to deal with drafts, water damage, and mold down the road.
Why Reinsulating Exterior Walls Matters
It can be tempting to rush straight to finishing your new exterior, but taking the time to insulate properly is one of the smartest moves you can make. Exterior walls are constantly exposed to fluctuating temperatures and moisture. Without proper insulation and air sealing, heat escapes in the winter, cool air leaks out in the summer, and moisture can condense on your wall sheathing. This leads to hidden mold, mildew, wood rot, and even structural decay.
Beyond moisture issues, poorly insulated exterior walls reduce your home’s thermal performance. Your HVAC system works harder, energy bills rise, and your newly remodeled exterior won’t deliver the comfort or efficiency it should. Proper insulation protects your walls, supports your siding, and makes sure your home stays dry and comfortable for decades. Upgrade your home’s curb appeal and energy efficiency with professional house siding in Harleysville.
Choosing the Right Insulation for Exterior Walls
Not all insulation is suitable for exterior walls, especially in areas exposed to moisture or extreme temperatures. Here are the top options to consider:
Closed-Cell Spray Foam
- Expands to fill every crack, creating an airtight and waterproof barrier.
- Acts as insulation, air barrier, and vapor barrier in one.
- Adds structural rigidity to walls.
- Professional installation required; higher cost.
Rigid Foam Board (XPS or Polyiso)
- Durable, moisture-resistant, and DIY-friendly.
- XPS is highly vapor-resistant; polyiso has a higher R-value but can lose efficiency in cold conditions.
- Can be cut to fit between studs and sealed with foam or tape.
Mineral Wool Batts
- Naturally hydrophobic and fire-resistant.
- Provides sound dampening.
- Requires a separate vapor barrier but handles moisture better than fiberglass.
Fiberglass Batts
- Affordable but absorbs water and loses insulating power if wet.
- Must be paired with a proper vapor barrier.
When comparing options, closed-cell spray foam provides the highest R-value per inch and the best moisture resistance, while rigid foam board and mineral wool are good DIY-friendly options. Fiberglass remains the lowest-cost choice but has the poorest moisture resistance and requires careful vapor barrier installation.
Step-by-Step: Reinsulating Exterior Walls
1. Prep and Safety
Wear long sleeves, gloves, eye protection, and a dust mask. Remove old insulation, debris, or damaged materials from stud bays. Inspect for signs of water damage, mold, or wood rot. Any issues must be fixed before installing new insulation.
2. Air Seal Everything
Use low-expansion spray foam or high-quality sealant around windows, doors, pipes, wires, and electrical boxes. Seal gaps between top and bottom plates and any penetrations through the exterior sheathing. Air sealing prevents drafts and moisture intrusion, maximizing the effectiveness of your insulation.
3. Install Insulation
- Rigid foam boards: Measure each cavity, cut boards slightly smaller than the space, and seal edges with foam or tape.
- Mineral wool or fiberglass batts: Cut to fit without compressing. Work around wiring and pipes by cutting and placing insulation snugly on all sides.
4. Install a Vapor Barrier (if needed)
Unless using closed-cell spray foam, add a vapor barrier on the interior (warm) side of the wall. Use 6-mil polyethylene sheeting, overlapping seams and sealing edges carefully. Avoid double barriers if the exterior already has a house wrap.
Common Mistakes to Avoid
- Compressing insulation: Reduces effectiveness. Fit it gently in the cavity.
- Leaving gaps: Even small voids reduce thermal performance; fill with spray foam.
- Incorrect vapor barrier placement: Always on the warm side of the wall.
- Ignoring old damage: Moisture issues must be remediated before closing walls.
Conclusion
A well-insulated exterior wall isn’t just about comfort; it protects your home from moisture, energy loss, and structural damage. Taking the time to insulate during an exterior remodel makes sure your investment looks great and performs well for years. Enhance your home’s exterior with durable and stylish house siding in Blue Bell.
If you want peace of mind, professional installation from Terrapin Exteriors guarantees your new exterior is properly insulated, air-sealed, and ready to perform. A properly insulated exterior wall today saves headaches and expenses tomorrow. Contact us today!