Attic Air Sealing & Insulation in Lansing, MI

Attic air sealing and insulation work together: we close the gaps that let warm house air rise into the attic, then add insulation so the ceiling holds heat. Skip the sealing and new insulation just filters the leaking air. In a Lansing winter, that warm, moist air reaches the cold roof deck, which is how you get frost on nails, damp sheathing and ice dams along the eaves.

Where the attic leaks

The big leaks hide under the insulation: top plates of interior walls, plumbing vent stacks, chimney and flue chases, recessed light housings, bath fan boxes, wiring holes, dropped soffits over kitchen cabinets and the attic hatch itself. Older Lansing houses add open balloon-frame wall cavities that run straight from the basement to the attic. We seal small gaps with foam, cover large openings with rigid board, and use fire-rated materials around flues.

How much insulation is enough

ENERGY STAR recommends R-60 for an uninsulated attic in Zone 5, which covers the Lansing area, and R-49 when adding to 3 to 4 inches already in place. Michigan's 2015-based code minimum for new ceilings here is R-38. In blown cellulose, R-49 is roughly 13 to 14 inches deep. Many attics we see have 4 to 8 inches of settled fill.

Foam on the floor or on the roof deck

Most attics are best handled on the floor: seal, then blow loose fill. When the furnace or ductwork is in the attic, or the ceiling is cathedral with no attic at all, spraying foam on the underside of the roof deck can make sense. It costs more, so we show you both options when both work.

Signs you need it

Icicles and ice dams, uneven snow melt on the roof, upstairs rooms that are hot in July and cold in January, visible joists in the attic, dusty dark streaks on old insulation (a sign of air passing through it) and frost on roof nails in February.