Radiant Barriers Help Insulation Do More

We all know the old song and dance: insulate and weatherproof your home to maximize your utility dollars. Filling all the gaps and keeping all the climate-controlled air where it should be is a huge part of creating a home that’s not only comfortable, but efficient. Or so we’ve been told. The truth is that there’s another step in the process that many homeowners are overlooking, and it’s both easy to install and inexpensive: a special kind of foil called a radiant barrier.

What are Radiant Barriers?

Radiant barriers aren’t much to look at. In fact, they pretty much just look like really heavy foil like you’d use on your grill or on top of a casserole dish. But they make up for looks in performance. According to Energy.gov, a website produced by the US Department of Energy, radiant barriers can reduce cooling costs by up to 10% in sunny climates, and may even allow a homeowner to install a smaller air conditioning system, saving additional money over the longer term.

They work by reducing the radiant heat that comes into an attic or other space. When roofing materials get hot from sun exposure, that heat eventually transfers into the attic via radiation. So, to slow or even stop this process, a barrier that’s designed to reflect that radiant heat back out of the attic is necessary.

Many houses lack radiant barriers, either because it wasn’t invented when they were built and no one thought to add it later, or because the climate where they were built was once considerably cooler than it is now. That doesn’t mean you can’t add one, though.

Installing Radiant Barriers

Installing a radiant barrier is not a difficult process, but it can be a time-consuming and messy one. After all, you’ll need to be in your attic for prolonged periods, working with a sort of heavy foil material that can be cumbersome for a single person to manage. But it’s definitely possible as an advanced DIY project.

When you install a radiant barrier, it’s really important to not only pay attention to which side is up on the barrier material, so the proper side faces the roof, but that you install it in such a way that it won’t be contaminated with things like dust and other debris. The more dust and material that collects on a radiant barrier, the less effective it will be.

In the past, some people have installed radiant barriers on top of their insulation, but this has proven to be a poor way of installing the material. Instead of the wanted effect of cooling the attic, in these homes, the radiant barrier instead interferes with the insulation’s ability to work properly. Since they also tend to act as a moisture barrier, radiant barriers can also trap moisture inside attic insulation, causing all kinds of other problems.

When installing a radiant barrier, hanging it along the contours of the attic roof or rafters is your best bet, but you’ll need to let the material droop slightly between attachment points to create a 1-inch air gap between the material and the bottom of the roof. You can also choose insulation with a radiant barrier built-in, called reflective insulation, where the barrier acts as the facing material.

Safety With Radiant Barrier Materials

Because radiant barriers are made of metal foil, they will conduct electricity. Many homeowners don’t consider this when installing them and may overlook serious hazards like contact with bare wire or old wire with failing insulation. Electricity can cause serious injuries or damage to homes, especially if the contact is prolonged and widespread, like it would be when accidentally electrifying an entire attic’s worth of foil.