Estimate area, bays, bundles, and total cost for wall and attic insulation.
"Bays" calculated based on Width / Spacing.
Standard bundles cover ~90 sq ft (e.g., R-13 wall insulation). Attic rolls vary (~40 sq ft).
Fluff it: Unfold insulation batts carefully. Don't compress them; compressed insulation loses its R-value.
Vapor Barrier: Facing (paper/foil) should generally face the warm-in-winter side (towards the interior living space) unless specifically building a hot-climate wall.
Cut Correctly: Use a straightedge and sharp utility knife. Cut insulation slightly larger than the cavity to ensure a snug friction fit.
R-Value measures resistance to heat flow. The higher the R-Value, the better the thermal performance.
Batts: Pre-cut pieces designed to fit standard wall stud spacing (16" or 24"). Best for walls and floors with regular joist spacing.
Rolls: Long, flexible strips. Best for open attics, crawl spaces, or covering long runs without many obstacles.
For insulation, 5-10% is usually sufficient. You might need slightly more if you have lots of pipes, wires, or odd angles to cut around. Compressing insulation to fit into cavities reduces effectiveness, so proper cutting is better than stuffing.