It’s the moment we’ve all been waiting for! After months of work in preparation, it’s the big day for actually blowing the insulation into the attic. Now is the time to buy the insulation, rent the blower, and slog through a long and hot day of loose fill fiberglass insulation installation!
A couple helpful tasks before adding insulation to your attic is to mark your desired depth and label anything you may want to find before you completely cover it.
To this end I made two different visual indicators, the first of which were brightly painted dowel rods to denote the insulation height, while the other were plastic flags affixed to the underside of the roof decking to mark anything of import below.
When adding blown-in insulation to an attic it’s recommended to have a barrier to prevent insulation from accumulating above the attic hatch. Without this insulation dam the next person who enters the attic will surely be covered by inches, if not feet, of fiberglass.
Here’s how I built mine from plywood to serve as inspiration for your own building efforts.
One task that needs to be completed before adding more blown-in insulation is to install attic ventilation baffles. Once finished we’ll be able to completely cover the attic floor, which will give us the best performance from the new insulation.
Currently we have a reasonable amount of old blown-in insulation that (mostly) covers the attic floor. An exception is along the external walls near the top plate, which is evident in the summer when that part of the ceiling is noticeably warmer than along the interior. (See my FLIR ONE for iOS post for proof!)
With the baffles installed we’ll have an even thicker layer of insulation with more consistent coverage. We also won’t need to worry about blocking the soffit vents so that our attic can passively vent. Hopefully the top floor of our house will stay warmer in the winter and cooler in the summer as a result.
A big culprit for air leakage in a home is through holes in the floor of the attic. These are often found in the top-plate, drop soffits, and chases and the volume of conditioned air that escapes through them is equivalent to leaving a window wide open the year round.
Air sealing these holes and gaps will greatly reduce the expensive flow of conditioned air from inside your home to outside. All it takes is the right tools, materials, and the patience to find and then cover and seal the offending areas.
Ducts that leak conditioned air into unconditioned spaces (such as your attic) can increase your heating and cooling bills.
Fear not, you can prevent that unnecessary waste by sealing and insulating your ducts with some inexpensive supplies and a little bit of effort.
Of the many prerequisite tasks to adding blown-in insulation to an attic, perhaps one of the most important is having an air tight and well insulated hatch to limit air infiltration.
What follows are the steps I took to increase the insulation and ensure a good seal between the unconditioned attic above and the conditioned room below.
One common source of air leakage in a home is through recessed light fixtures, otherwise known as can lights. They may look nice and illuminate well, but they’re a great conduit for conditioned air to leave the building envelope.
One way to improve home heating and cooling efficiency is to eliminate the passage of air through the recessed lights. The general idea is to cover and seal the lights, which I decided to do with a specialized insulation barrier called CanCoverIt that I sealed into place with spray foam insulation.
Chimneys are a great conduit for removing smoke and gases from your house, but they’re also notorious for allowing conditioned air to escape to the outside via the chase that surrounds them.
If that weren’t enough of a concern, they’re also fire hazards when carelessly insulated with materials that aren’t properly fire-rated.
Fear not, you can resolve both issues with a little know-how and the right type of materials.
There are a lot of tasks to do before adding extra insulation to an attic, especially in an older home. They vary from the easy to the onerous (looking at you attic baffles) and are even more of a pain to complete when the lighting is poor.
To improve the lighting in the attic I stapled a couple of lengths of LED strip lights to the underside of the ridge board. The strips are only plugged into an extension cord while I am working. They can also be removed when I finish insulating the attic, if I choose to do so.