Insulating Your Attic

Insulating Your Attic

Hiring a professional to insulate your attic would cost you somewhere between $1,500 and $2,000 for a 1200 square foot house. If you follow this guide and do it yourself, you would be looking at about $500. This isn’t a difficult job, and the benefits outweigh the work involved, but it’s sweaty, dusty work. To make the most of your schedule, ask for an extra set of hands and set aside a whole weekend: you’ll use Saturday to prepare your attic, and the Sunday to blow your insulation. Come the end of Day 2, you’re going to be exhausted, but saving up to $1,500 now, and up to 25% on your future utility bills should be enough to turn that frown upside-down.


Step one: seal your attic bypass and the leaks. Pull back the insulation, use expanding foam to seal the gaps in pipes, perforations in the ceiling, and holes where wiring goes through. The pipes need to be sealed all the way around with either caulk (for gaps less than 1/4-in.) or expanding foam. You will need to seal off any opening, crack, etc., because each of these is the same as having holes in your ceiling measuring 2 feet wide (for each crack!).

Step two: Add vents. The vent’s chute needs to be positioned so that the bottom is 6 in. inside the overhang. Use a squeeze stapler to put it in proper place.

Step three: Insulate your access door. Cover your hatch with a cushion of fiberglass insulation to ensure that there won’t be any air leaks. You need two layers of cut fiberglass batt (R-19) insulation. Cut it to be larger than your hatch. Staple duct tape onto the hatch’s edges, securing its location.

Step four: mark your reference lines. Using a permanent marker, measure from the drywall upwards to your desired level. Repeat this process on several trusses all around the attic to ensure an even coating in step six (after common mistakes).

Common Mistakes

This section is a how-to guide for combating the three most common mistakes people make.

The following are suggestions on how to avoid unpleasant consequences.

  1. Seal off all points air can leak from before you do anything else. Double and triple check to make sure.
  2. Use a stick or broom handle to push the insulation that’s already in your attic to the edges, this will ensure that insulation gets out there.
  3. MOVE SLOWLY, you will step through the ceiling if you are not careful, so consider standing on a piece of plywood. You can feel the joists through your shoes if you wear a pair with rubber soles.


If you are reading this section and have not completed steps one through four, please go back and start from the beginning, or you will run into the mistakes that have been mentioned.

Step five: fill the blower. You will need your assistant for this step. Have him/her crumble the cellulose and load the hopper (you don’t want it clogging the hose) while you are blowing the insulation. You can adjust the door of the hopper to adjust the speed at which the insulation comes. Communicate with your assistant using your cell phones, walkies-talkies, or just by turning the blower repeatedly on and off.

Step six: Fill ‘er up! Start from the point farthest from your hatch, ensure that your old insulation is far in the edges (see common mistake number two) and then blow insulation ontop of the old stuff. Situate yourself in the center of the attic and fill three bays at a time. Push the hose out and blow the eaves first. Then using a slow and steady back and forth motion (e.g. sweeping), pull back the hose until you’ve reach the desired depth (check the marks you made to ensure an even coating all around). Pivot and fill the other side of the attic by repeating this process.