Covering Gables in the Attic
A gable is the triangular portion of the wall in an attic that is between the edges of a sloping roof. The size and shape of a gable wall depends on the structural layout of the attic, but all attics have some type of gable end. A gable wall (also called a gable end) more commonly refers to the entire wall, including the gable and the wall below it. If you have any walls catching direct sunlight in your attic, you want to address the problem with radiant barrier as your first line of defense against the heat gain.
Can you attach a radiant barrier to a gable wall?
The simple answer is yes; if the gable wall is catching direct sunlight then you want to cover it with radiant barrier.
Why? Because when the radiant rays from the sun hit that wall, it absorbs that radiation and re-radiates it across the attic, just like the slopes of the roof do. Therefore, it makes sense to utilize a radiant barrier in this area to block radiant heat gain. Simply install the foil as you normally would, and pay mind to allow for proper airflow. If you do this, you will add to the overall effect of a cooler attic space, and a more efficient home overall.
Installation Is Simple
Installing a radiant barrier on a gable end is no different than installing a radiant barrier on the sloped sides of your roof. Just like with any radiant barrier, you want to ensure an air gap on at least one side of the foil so that radiant heat is present and the foil can work to block it. When installing radiant barrier foil on a gable wall, the main objective is to get as much covered as possible, without obstructing natural airflow.
Some gable walls are plain walls, with no vents. In these cases you can completely cover the wall, as if you were wall papering the surface. However, if your gable end has vents on it, you will need to ensure that when covering the area you leave a gap or space above and below the vent. This can be achieved by slitting the foil or by running two separate pieces around the vent opening to control the spacing. Another option is to leave the vent completely open and just staple the foil up around it. Whichever install method you choose, the main point is to leave space for air to flow to be maintained.
If you plan on finishing out the wall and including it as part of a living space, then the installation would be a little different. Instead of the attic air being the required air space, you’ll now have to create an air space. Attaching wooden strips vertically on the gable wall and then installing the foil inside each bay created by the wood strips is the easiest way to do this. Staple the foil to the sides of the wood strips and make sure it won’t sag or make contact with the deck when you add insulation.
If you’d like to see some examples of successful attic installations, check out our customer DIY Project Gallery.