One of our readers asked the other day where the biggest air leaks typically occur in a home. From my experience, one of the most overlooked places in a home for air leaks is the exterior door. Most homes have at least two exterior swing doors so it’s imperative that we keep them adjusted properly. Let’s take a look at how much air we are talking about and how to make a few simple adjustments.
Air Leaks in Exterior Doors: Quantity Analysis. Let’s say you have two exterior swing doors that are three feet wide by 6’8″ tall (the typical height for an 8 foot tall ceiling). The perimeter of each door measures about 19.33′ (6’8″ + 6’8″ + 3′ + 3′). Now let’s suppose you have a gap around your door that is equivalent to the thickness of a penny (.061″). Trust me, this is totally possible…I have seen gaps as large as 3/8 of an inch!
In this scenario, you end up with the equivalent open area of 14 inches per door. Now multiply that by the number of doors you have and you end up with a huge area for air leaks! If you have two exterior doors with the penny gap around them, you end up with the equivalent of a hole in the side of your house that you could fit a high school football through! Ouch! When it’s 20 degrees outside, this can lead to some serious air leaks with really ugly heating and cooling bills.
If you had a hole in the side of your house the size of a football, you would most likely do something to cover the hole. Yet most people never do anything to stop the air leaks around their exterior doors. So what are your options for stopping the air leaks in your exterior doors?
Adjustable Thresholds: The top picture above shows an exterior door threshold. Many of these are adjustable. If adjustable, they contain springs inside that allow you to turn the screws counterclockwise and let the tension out. This raises the threshold to eliminate the gap between the door sweep (the rubber piece attached to the bottom of the door) and the threshold. If your exterior door doesn’t have an adjustable threshold, you may want to take a trip down to your local hardware store. Most hardware stores have threshold pieces you can add on top of your existing threshold to help fill the gap. If you do add a piece on top, be sure to seal up the screw holes with a good quality silicone to prevent water leaks.
Door Sweep: As mentioned above, the door sweep is the rubber piece attached to the bottom of the door. The sweep is designed to compress when the door is shut. Because of this, it wears out over time as the door is opened and closed repeatedly. So, you will want to inspect the sweep for wear every so often and replace. Again, check with your local home improvement store for replacements. Be sure to take you existing sweep with you for a match. Or, you could try contacting the door manufacturer.
Weatherstripping: Exterior door weatherstripping is designed to compress when the door is shut. Much like the sweep at the bottom of the door, this compression should provide a tight seal around the door to help prevent air leaks. If the weatherstripping isn’t getting compressed enough when the door is shut, air leaks will ensue. The easiest way to tighten up the seal between the door and the weatherstripping is to adjust the door striker plate. The striker plate is the little piece of metal with the rectangular opening that is attached to the door jamb. The purpose of the striker is to accept the bolt from the door knob (this is what locks the door and keeps it shut). By moving the striker plate closer to the weatherstripping, the door will shut more tightly against it. This should eliminate some of your air leaks.
If you can’t seam to get a tight seal around the entire perimeter of the door, you can replace the existing weatherstipping with a thicker one. These can be purchased from your local home improvement store. Just make sure you cut the material to the proper length to prevent gaps and make sure you secure it permanently in place. You don’t want the weatherstripping to get loose and fall out every time you open the door.
Adjustable Hinges: Some of the more expensive doors have special hinges that allow adjustments to be made. Typically, these adjustments can be done with a screwdriver. By loosening up the screws, you are able to move the hinges to create a tighter seal. If you think you have adjustable hinges but don’t know how to operate them, check with the door or hinge manufacturer.
Storm Door: If the above items don’t take care of your air leaks, you could install a new storm door to provide an added layer of protection. Some storm doors come with a glass insert that can be replaced with a screen or opened in the summer to provide drafts. Make sure you install the screen or crack the glass to let the hot air out in the summer…you don’t want the green house affect of the glass door to melt the paint on your door!
For more ideas for minimizing air leaks when building your new home projects check out this article…Energy Efficiency: Builder Tips for a Tight Home.