Attic Insulation & Air Sealing in Muskegon, MI

Attic insulation and air sealing in Muskegon is as much about the roof as the rooms below. When heat leaks from the house into the attic, it warms the roof deck and melts the snow from underneath. The meltwater runs down to the cold overhang, freezes, and builds an ice dam that backs water under the shingles. With 87.2 inches of snow in an average year, Muskegon roofs carry plenty of snow to melt. The cure is to keep heat out of the attic.

Seal before adding depth

Most attic heat loss comes from air leaks, not from thin insulation. Warm air flows up through gaps around chimneys, plumbing vents, wiring holes, recessed lights, bath fans, the attic hatch and the top plates of interior walls. Older balloon-framed houses can have open wall cavities running straight into the attic. We seal those with foam, caulk and blocking first, then add insulation.

How deep

Muskegon County sits in Climate Zone 5A on OpenEI's list. ENERGY STAR recommends R-60 for an attic with no insulation, or about R-49 added over 3 to 4 inches already there. Blown cellulose or fiberglass is the usual way to get there on an open attic floor. Consumers Energy's rebate table gives its highest attic rebate for reaching R-60 or more.

Ventilation and the eaves

A vented attic needs air moving in at the soffits and out at the ridge or roof vents. Baffles at the eaves keep insulation from blocking the soffits, and that cold air washing the underside of the roof deck helps prevent ice dams. Bath fans that dump into the attic get ducted outdoors.

Story-and-a-half houses

Many Muskegon houses have upstairs rooms built into the roof with short kneewalls and sloped ceilings. They are notorious for ice dams because the sloped ceiling is often thinly insulated and the attic floor behind the kneewall is open to the floor joists below. We seal and insulate those areas, and use closed-cell foam on sloped sections where there is little depth.