Basement & Attic Insulation| Ranch Style Home | Biddeford, ME | Rook Energy Solutions

Ranch style home - attic insulation

UPDATE: This home was weatherized in 2012 - the home owner has reported ~30% savings annually from their pre-weatherization heating bills.

This small ranch in Biddeford offered many of the same issues that we regularly see in a New England home; excessive fiberglass insulation with mismanaged airflow leading to devalued insulation. The home owner complained of ice damming issues, drafty spots, and high energy bills.

The Issues:

Thermal photos: air leakage & devalued insulation

Thermal Photos: Far left - basement rim joist air leakage leading to devalued fiberglass insulation. Middle left - mismanaged air flow from eave soffits, devaluing attic insulation. Middle right - recessed light air leakage. Far right - attic hatch air leakage. The last 2 photos were taken with the blower door running and show colder attic air being drawn into the heated space. Under normal conditions these avenues of air leakage are where interior heat can easily escape into the attic, effectively heating the roof deck - melting snow - creating ice dams and wasting energy.

The Solutions:

In order to improve seasonal performance and to really see changes in your structure, you have to start fresh. Adding insulation simply won't do, in almost every scenario you have to air seal first and then add insulation. The only way to effectively air seal is to remove existing insulation. Just to drive home the removal of insulation solution, fiberglass is the perfect home for rodents - so when you remove it, you're really cleaning house.

Removed existing fiberglass insulation and installed 3" closed cell spray foam insulation to the existing rim joist and covered the sill plate. 1" of closed cell spray foam insulates to R7 and air seals perfectly.

Removed existing fiberglass insulation & old proper venting. Installed Accuvent style proper vents which staple in easily to the top-plate and create a dam for cellulose to abut. Now soffit vent air is managed properly and will travel up the roof deck oppose to entering the existing fiberglass insulation.

We sealed the chimney chase (a highway for heat to enter the attic) with sheet metal, canned foam, and fire rated caulking (where it abutts the chimney), and wrapped the base of the chimney with Roxul Insulation (fire barrier) so cellulose can fully abut the chimney.

Prior to adding any insulation, we air sealed every chase hole and gap/crack in the attic (left photo show air sealing where drywall abuts an interior wall topplate. Canned foam is perfect for attic air sealing.

Tenmat recessed light cover

To air seal and insulate the recessed lights we like to use Tenmat recessed light covers. They are made of Rockwool (same material used to wrap the base of the chimney) and can easily be installed, cut, and air sealed around existing recessed lights. It is very important to note that you can only cover Insulation Contact (IC) rated recessed lights - if your attic recessed lights are older and are NOT IC rated, you will have to replace them first.

Beyond all this work we also air sealed and insulated the attic hatch (pull down stairs) by building an insulated dome to encase the stairs with 4" of rigid board on the top of the enclosed dome, and a 17" plywood barricade around the dome so insulation can abut it, we also installed weatherstripping at the trim  of the dome cover with hook & eyes to compress the hatch against the weather stripping.

This home owner also wanted to retain the attic storage that existed, so prior to insulating we installed a 2"x8" frame to sit on top of the existing 2"x6" attic joists and we built a platform with an edge. This 14" cavity under the storage platform allows enough space to get adequate R Value, while still retaining attic storage. 

The finished product of this job was a completely transformed basement rim joist and attic flat. Prior to commensing this weatherization project we performed an energy audit as well. The initial blower door number was 2820 cfm50 and post weatherization this number was reduced to 1300 cfm50 which put them right at the building airflow minimum and will lead to large energy savings and increased seasonal performance.