Attic Insulation Case Studies: Conditioned Attic in Fairfax Va

Challenge

The customer, a world class Industrial Hygienist who focuses on indoor air quality in residential properties, asked us to come and evaluate his home for potential improvements to his comfort and to reduce his energy bills.

As a building scientist himself, our analysis was sure to be scrutinized for accuracy and the logic of our proposed solutions.  We had to be data driven and accurate with solutions that met his exacting requirements.

The home was built in the 1950’s, and had then been expanded and modernized with care paid to the details into a model of what a well maintained house should be.  From the first time you see it from the street you know that it is a well taken care of home.

Our blower door test did reveal some potential for improved thermal performance.  Specifically, one of the areas of concerns was a small walk-in attic located adjacent to the master bathroom.  This attic was used for storage and offered a convenient way to store those items in the house that are not used frequently.  But it leaked air into the living space, and was as hot as a roasting pan on Thanksgiving during our analysis.

Solution

The solution was to condition the attic space.  Several options were proposed to accomplish this task.  We considered both Closed and Open Cell Spray Foam, but rejected these options due to their impact on indoor air quality and the chemical components that they add to the space. 

We also considered a traditional Super Attic ™ as a solution but again rejected it as it required the use of luminescent paint to provide a thermal barrier.

We settled on a Hybrid Super Attic ™ solution that used a combination of 2 inch Silverglo with a covering layer of Thermax for fire protection.

To start the project we removed the insulation from the attic floor.  This is required to re-locate the thermal barrier of the home to the roof deck, and provided for a clean installation.

Next we cut blocks of Silverglo ™ to create an air barrier at the outer edge of the attic.  Each of these blocks were then foamed in place with a Dow Froth Pak – 2 part foam kit.

Then ¾” plywood deck was installed for a rigid surface to store contents on.

Lastly, we installed a layer of Silverglo ™ radiant barrier facing the sun to keep the room cool during Virginia’s blazing hot summers.  This is a feature that Super Attic ™ provides that Spray Foam cannot.  Thermax was then used to add additional insulation and to provide for fire protection without the use of luminescent paint.  This is another feature that spray foam could not provide.  All joints were then taped with foil tape to provide a continuous air barrier.

The owner now has a really nice conditioned storage space that was an inexpensive option compared to most other options.  He is more comfortable, his energy bills are sure to decrease and he has more room to hide the Christmas Presents!

Call us if you need help working through the pro’s and con’s of different ways to condition your Northern Virginia attic, make your home more comfortable, or save energy.

Project Summary

Engineer: John W. LeVan

Energy Consultant: Mike Dowling

Project Manager: Mike Wilson

Industrial Hygienist: Inlogix