Insulation Upgrades

Basement & Attic Conversions

Insulation Upgrades Meeting Current Michigan Energy Code

Insulation in a basement or attic conversion requires selecting the right product for the specific application — not just meeting the R-value number. Fiberglass batts placed in a stud wall cavity against a Michigan foundation wall trap moisture behind them under certain conditions and create mold even when no liquid water is present. Closed-cell spray foam applied directly to the foundation wall surface functions as both insulation and vapor retarder, eliminating that risk.

For basement walls, we use closed-cell spray foam or rigid foam board with taped seams. Both are applied directly to the foundation concrete before framing goes up. We then frame stud walls in front of the insulation layer for drywall attachment and any additional insulation in the cavity. Current Michigan energy code requires R-15 continuous or R-19 cavity insulation on basement walls — we verify compliance before closing walls.

For attic conversions, ventilation channels between insulation and roof sheathing are non-negotiable. Blocking soffit-to-ridge airflow with insulation causes moisture accumulation in the sheathing and accelerates ice dam formation. We install rafter baffles at every bay to maintain airflow before placing any insulation. Spray foam at the rafter faces is an alternative that eliminates the ventilation channel requirement by creating an unvented roof assembly — more expensive, but it simplifies the detailing.