Insulating your Attic

Winter is almost here, and we are already beginning to feel the cold settle in here in New England. Now is the perfect time to start insulating your house before the real winter cold fronts start to hit us. In this four part series, we will look at the most common places you suffer heat loss in your home. This blog will take a look at the best ways to weatherproof your Attic for this upcoming winter.

We are finally at the end of our multipart series on insulating your home, and we’re ending with the one area that can hit your energy costs the most this year; The Attic. Attics can be responsible for up to 25% of your heat loss in the winter. That can add up to be a big chunk of change by the end of the year. Your main goal with attic insulation is to keep your attic as close to the temperature outside as possible. This helps to prevent mildew, rot, and saves you from spending a fortune on both heating and cooling bills. A good way to tell that your attic is not properly insulated is the presence of icicles and ice dams on your roof.

Lucky for you, Koopman is here to make it as easy as can be. Let’s finish this series big with the top of your house!

Blog Series: Insulating your home

Part 4: Attic
Difficulty: Medium
Time: 3-5 Hours

In this instructional DIY blog you will be dealing with expanding foam sealant and exposed fiberglass insulation. It is recommended to have heavy gloves, eye protection, boots, and body covering on at all times. When dealing with insulation, a face mask should always be worn.

Step 1: Electrical Boxes

Electrical boxes that anchor light fixtures and ceiling fans to the ceiling below are notorious for having air leaks. Thankfully they are not only easy to find, but easy to seal as well. Looks for electrical wires running across the joists and they will almost always lead to an electrical box. If you have recessed lighting, there is a special way to take care of that that we will cover a bit later on.

Expanding Foam electrical boxOnce you find the electrical boxes, it’s time to get out your insulating spray foam. You will want to check with your local fire code to ensure that you’re using using the proper grade of fire resistant foam. If you’re unsure, Koopman sells a variety of different up-to-code foams from Great Stuff including foams for special purposes including:

  • Fireblock Insulating Foam
  • Window and Door Insulating Foam
  • Gaps and Cracks Filling Foam

Once you have the proper foam, don your protective gear and get to work on those electrical boxes! Simply fill in the gaps around the edge of the boxes, where the wires penetrate the box, and the seams of the box itself. Repeat this for each electrical box you find, as well as following the wires back to their source and sealing the holes they run through.

Next step is going to be to tackle any recessed lighting. Turn the light on below and look at the can to see if there is any light coming through. If light gets through, you can bet that air would get through as well. To fix this we are going to need to determine if the light is IC (insulation contact) rated or not. Check the outside of the can first to see near where the wires exit to see if there is an IC rated stamp. If you don’t find anything on the outside, head downstairs and look for a stamp inside the can. If you don’t see a stamp or if the light fixture is old, and any writing illegible, then it’s not IC rated, and we will need to take a different approach to insulation.

Cans can get very hot very fast. Always wait 10 minutes after shutting off the light before you touch the can!

IC rated cans are able to have insulation placed right over them, whether using fiberglass batts or loose fill insulation.

Recessed lighting insulation boxNon-IC rated cans need a 3 inch clearance from all insulation, but we can cover them with rigid foam insulation. Measure the size of the can and use those dimensions (plus 3 inches) to cut a box out of rigid foam insulation. Seal it all together with construction adhesive and aluminum foil tape. If there are any joists or wire penetrations, be sure to cut out notches for them as well. When you’re finished place your light fixture’s new protective home over the top, and seal around the edges with your insulation foam.

Repeat this for all recessed lighting cans you have in your attic.


Step 2: The Hatch

Hatches are generally very large air leaks in your house, letting a lot of that heated air up into the attic. They are also the easiest part of this job to insulate

There are two main types of hatches leading up to an attic. A pull down hatch with a ladder, or a solid wood “door” that lies across the top. The easiest way to stop the air leaks through the hatch is to buy a hatch cover. This is a layer of foam insulation that is dragged over the top of the hatch every time you climb downstairs and you move aside every time you climb up. It’s super effective and super easy!

If you have a door hatch there is also another more permanent method you could use. Cut a 2″ piece of rigid foam insulation the exact size of the hatch and use construction adhesive to hold it in place on the back of the hatch. After that, climb down and attach weatherstripping to each side of the hatch in the notch where the doors sits. Seat the door back in place and you’re good to go.

Step 3: Soffit Vents

proper_vent_installedBefore we can lay the insulation down we need to make sure that the soffit vents are properly protected. Soffit vents are a type of ventilation system that draw up air from under the roof to increase air flow and discourage moisture build up that could result in high humidity and mold growth. They are always combined with a higher vent that draws out air and moisture.

For this we’re going to need a set of Proper Vent baffles that we will staple to the bottom of the roof decking, in between the roof rafters. Make sure you put a baffle above each soffit vent to encourage air flow!

Step 4: Insulation

When installing insulation, be sure to cover any exposed skin as well as wearing protective gloves, glasses, and a gas mask. You don’t want this stuff on you or in you!

There are 2 main types of insulation you can use, loose fill or batt. There is debate as to which one works better, but ultimately it comes down to how well the insulation is installed.

Loose fill insulation blowingLoose Fill: As the name implies, loose fill is made from little pieces of cellulose or fiberglass. It is usually installed using a blower to spread it evenly across the surface of your attic. Cellulose, a recycled paper material that is treated with both a flame and rodent retardant, is the most common type of self installed insulation. Fiberglass generally requires hiring a professional to fill with. To install cellulose, simply spray it with a blower across your attic, covering it evenly until you reach the manufacturer recommended density.

Koopman Lumber is proud to cell Greenfiber loose fill cellulose insulation. We also rent our Greenfiber blower, meaning you can get everything you need in one stop. For more information head over to Koopman Rentals to learn more about Greenfiber and how Koopman Lumber can save you money this winter!

Batts: Fiberglass batts are a simple install. They come in rolls of various lengths and are faced or unfaced.

  • Faced rolls are used when installing new insulation. Make sure they are the proper width and height to fit in between the joists and cut down to length by simply compressing and then cutting with a hand blade. Install them by hand for the length of the joist. Make SURE that the faced (paper) side of the insulation is facing towards the living space (down).
  • Unfaced rolls are used when placing new fiberglass rolls over an existing loose fill insulation. Using faced insulation would cause moisture build up here, which would be very bad for the joists. Spread these batts out perpendicular to the joists underneath being careful not to compress the existing insulation.


Wrap Up

We’ve made it folks, we’re at the end of our journey through home Insulation! If you followed all the steps up until now then you should notice a nice drop in your home’s heating and cooling bills throughout the year. Don’t forget to inspect everything yearly to make sure that they’re all nice and sealed.

If you have any questions about insulation or home energy efficiency then reach out to us online at  Thanks for tuning into this blog series, we’ll see you next time!