Air Sealing & Cellulose in a Hayes, VA Attic
Challenge
This homeowner wanted to add insulation to their attic. They had noticed some uneven temperatures throughout their home and had been experiencing high energy bills.
At our inspection, we found that there was minimal blown-in fiberglass insulation in the attic and numerous gaps and holes allowing conditioned air to escape into the attic and out of the home. In summer months, the sun beats down on the roof, heating it up. That heat radiates down into the attic, heating the space well above the outside temperature. With minimal insulation, the attic then heats up the ceiling which radiates heat into the rooms below. This makes it hard to cool the rooms down the HVAC unit struggles to keep up.
In the winter, the attic is the same temperature as outside and cools down the ceiling. Rising warm air meets the cold ceiling, gives up its heat, and falls, this is called convective looping. The process makes the home feel drafty and hard to warm up. Leaving homeowners uncomfortable and with high energy bills.
Solution
To help this family make their home more comfortable, we began by removing the existing blown-in fiberglass insulation. This gave us clear access to all the gaps and holes such as top plates and utility penetrations so that they could be air sealed. These holes are a natural part of a home’s construction and are almost never sealed after lines have been run and sheetrock has been hung. Sealing these holes prevents conditioned air from escaping out of the top of the home, via the stack effect.
Next, we installed PV’s (polystyrene vents), this allows ventilation of the roof and keeps insulation from blocking the soffit vents, or drift in the insulation occurring due to airflow. A dam is then put up around the attic access to prevent insulation from falling in. Then we installed a fresh blanket of R-38 cellulose insulation. Blown-in Cellulose has a higher R-value per inch than blown fiberglass. Because it is made of small particles, the material nestles well and does not have a lot of air space for the temperature to transfer. The cellulose product we use is 85% recycled material, such as newspaper and 15% new materials. It also contains a borate which helps to deter pests.
Air sealing helps to prevent air leakage out of the top of the home, therefore keeping the air the homeowner pays to heat and cool inside the home longer. A proper bed of insulation on the ceiling reduces the heat transfer to the rooms below, evening out temperatures from room to room. This solution helps the homeowners have a more comfortable space and helps to reduce energy bills and wear and tear on the Heating and Cooling unit.
