Insulating the Attic Floor or the Pitched Roof: Which Is the Better Approach?

Just how much impact does a well-insulated attic have on the effectiveness of a home’s overall insulation system? What most homeowners need to realize is that the attic, being the topmost part of the house and being connected to the roof, is an area that can quickly gain or lose heat through conductive heat transfer. It is a space that is susceptible to outdoor temperature extremes, which, in turn, affect the temperature levels within the  house.

Given the importance of insulating your attic, how do you then go about it? Do you need to install insulation both under the floor of the attic and under the slope of the roof? Or should you prioritize one over the other? In this short guide, we’ll attempt to answer this common query from homeowners with a few quick tips. The answers determine a lot of important decisions you’ll be making for your attic, such as what type of insulation to buy and how much of it to spend on.

Insulating a Finished vs. an Unfinished Attic

The rule of thumb is that if the attic is an unfinished space, insulating its floor is often sufficient enough to insulate this part of the house from the living spaces beneath. This is because you are already effectively insulating the ceiling of these living spaces.

On the other hand, if your attic is a finished space—meaning you use it either as a storage space or as living quarters—it would be best to insulate both the slope of the roof and the attic floor. Insulating the pitched roof does the job of preventing outdoor heat or chill from infiltrating the building envelope, while insulating the attic floor prevents heat transfer from occurring between the attic and the spaces underneath it.

Insulating Cathedral Ceilings

If your home has cathedral-type ceilings, then insulating the roof should be your top priority. This is because the ceiling directly underneath it is essentially part of the building envelope. Having such a cavernous ceiling design can expose the upper part of your house to a lot of conductive heat transfer if the ceiling is not properly insulated. This means your house could get hot or cold fast, and your heating or cooling system might not be able to cope well in terms of maintaining the indoor temperatures you desire. Roof insulation prevents heat from easily leaving your home during the cold months, while also preventing the ingress of warmth when you’re trying to cool your home during the hot summer months.

Choose the Best Type of Insulation for Your Attic Floor and Pitched Roof

The good news is that insulating your attic floor or your pitched roof is a relatively easy task. You can greatly improve the level of comfort inside your home simply by replacing or improving the insulation in these parts of your house. One of the most convenient and cost-effective ways to do this is by using insulation batts or rolls, which you can immediately purchase from hardware stores.  If you’re finding it challenging to install these blanket-type insulation products because you need to place them around irregularly shaped architectural assemblies, blow in insulation is an alternative you can consider. This is definitely a good option if you’re insulating an unfinished attic.

There are other options besides that you can explore as well. Spray foam insulation, for example, is also a good choice for insulating unfinished attic floors because it ensures that every crack, gap, or air hole is completely sealed off, preventing air and moisture from penetrating the attic. There are also roofing panels that come with built-in insulation cores. These are perfect for new construction projects, but you can also use them in existing structures, depending on the extent of refurbishment that you are willing to accomplish for your home.

In the end, what’s important is that you take into consideration what your attic’s role will be in your home. Insulating it properly will depend on its existing condition and its intended purpose. Hopefully, these tips have given you a clear idea of how to insulate your attic floor and your pitched roof, thus ensuring you a successful home improvement project!