Adventures at 1628: How to: Insulate an Attic

Tuesday, February 22, 2011

How to: Insulate an Attic

It is not very cost effective to use spray-foam insulation in the attic so we chose to use a blown-in fibreglass from Owens Corning. Fortunately Home Depot now rents the equipment for blown-in insulation so we were able to do it ourselves for under $300.

Materials:

Blown insulation
Batt insulation
Blown insulation machine
Attic vents
Mask
Glasses
Gloves
Ruler

Step 1: Preparation

In order to prevent the insulation from falling out the attic door, we built a short wall out of plywood to hold the insulation in place.

We also installed attic vents to allow airflow from the soffit to the attic and installed batt insulation between the rafters.

Step 2: Blow in Insulation

In order to qualify for the government rebate we need to achieve R50. We chose to ignore the contribution of the batt insulation and install the 19" of blown insulation needed for R50. When you rent the machine they provide you with handy paper rulers to measure the depth of the insulation.

Following the instructions in the Owens Corning installation video, the process is surprisingly straight forward and easy:

Snap together the two halves of the machine and plug in. It is recommended that the machine be located outside of the house but it does not produce any exhaust so we chose to put it inside to avoid having to clean insulation out of the snow.
Connect hosing to machine.
Turn on machine.
Cut bags of insulation in half and feed one half at a time into the opening on the machine. Ensure that you do not feed the plastic bag into the machine - a cutting tool on the inside of the machine makes this very easy.

Begin blowing insulation!
Aim the nozzle about 8' in front of you and use your hand to direct the insulation downwards.

Continue to blow in insulation until the entire attic is covered in an even layer. Make sure you start in the furthest corner from your attic access and work your way out!