Weatherstripping Doors

While windows attract most of the attention when it comes to energy efficiency, doors can play a major part in what can go wrong -- or right. Doors have a particularly difficult role to fill. Not only do they need to open and close smoothly and easily, but they also have to seal tightly to keep out drafts, and must have at least some insulative value to keep cold at bay.

There are many different options on the market that can be used to upgrade a door's existing weatherstripping. Some of the most effective are types that contain a vinyl bulb or padded strip set into the edge of a conventional wood doorstop. The wood part is nailed to the doorjamb and is flexible enough to conform to even a badly warped wooden door. The vinyl bulb or strip seals out air movement, but is gentle enough that the door's function is not affected.

Other types of weatherstripping include thin bronze or brass strips that are nailed inside the jamb where the door closes. Small nails are driven along one edge of the stripping while the other edge is sprung outward slightly. When the door closes, it contacts the metal strip, bending it a bit and ensuring tight contact with the door edge. This type of weatherstripping is time-consuming to install correctly, but it lasts for years and is an effective draft stopper.

Foam tape is usually ineffective as door weatherstripping. Even the thinnest foam tape is too bulky to fit along the edge of the doorstop, and if applied in this area, it causes the door to bind and not shut properly. Foam tape is also not durable enough for everyday use in this type of application and soon fails, falling off the doorstop or tearing.

Some contractors are equipped to install a type of vinyl bulb weather stripping that is cut into the door frame with a special tool that resembles a router and cuts a small groove into the intersection of the doorstop and the jamb.

A barbed fin on the vinyl bulb weatherstrip is pressed into the groove, and friction keeps it there. This type of weatherstripping is very effective if installed properly, but the hard part is finding someone who has the equipment and know-how to install it.

Door Sweeps and Adjustable Thresholds

While weatherstripping takes care of weatherizing the top and sides of a door, there's still one edge left to deal with -- the threshold. And it's a tough area to address; thresholds accumulate grit and dirt and are subject to a lot of wear and tear. Manufacturers have come up with dozens of solutions to the problem of stopping drafts at the threshold level. Some replacement thresholds are complicated to install. They may require removing the door or even cutting off the bottom of the door. Others are easier to install but don't last long in extreme environmental conditions.

Instead of ripping out the entire old threshold and replacing it with something new, you may consider installing door bottoms or door sweeps. Door bottoms attach to the bottom of a door and can be adjusted to lightly graze the existing threshold as the door closes.

Door sweeps attach to the inside of the door near the bottom edge -- the door does not have to be removed -- and consist of a brush or pad that contacts the edge of the threshold as the door shuts. Some doors have a spring-loaded mechanism that snaps the sweep material down as the door closes and retracts it when the door opens, thus creating clearance under the door for an entryway mat. All of these products depend on careful installation to be effective.

On particularly difficult doors to seal, it is worth considering installing a door bottom as well as a door sweep. Much of the draft that gets by the first line of defense will be stopped by the second.

Some doors have adjustable thresholds, but few homeowners make the effort to adjust them as time, settlement, and wear take their toll. It's a good idea every now and then to get down on your hands and knees on the inside of the house in front of an entry door, press the side of your face to the floor, and look at the area where the threshold is supposed to come into contact with the bottom edge of the door. Often you'll see a wide gap; that's where air can breech the door's line of defense.

Adjustable thresholds are usually made from wood or aluminum (sometimes both), and the adjustable part is covered with a removable, replaceable strip of vinyl. After removing the vinyl, you'll see several large screw heads. Those are the adjustors. By tightening or loosening the screws, you can cause the center, adjustable part of the threshold to rise or fall. You'll have to use trial and error to determine how far up or down to move the adjustable portion, but it's worth it to get it right. Once the vinyl strip is back in place, you should not be able to see light coming under the door, and there should be just a little resistance or drag as the door bottom passes over the threshold. If you raise the threshold too far and create too much drag, both the door bottom and the vinyl strip will wear out prematurely.

Older doors equipped with vinyl door bottoms and adjustable thresholds may suffer from torn or worn parts. While some generic replacement parts are usually available at hardware stores and home centers, the best bet for a perfect match is to contact the original manufacturer of the door.

Storm doors, like storm windows, can add draft-stopping ability, insulation, and protection to a home's entry doors. The better the installation and the tighter the fit of a storm door, the more effective it will be. Aluminum storm doors have frames that screw to the outside of the door casing. There might be gaps between the frame and the casing, and those can be filled with caulk.

Another area of potential air infiltration is the door bottom. Most storm doors have an adjustable door bottom that can slide up or down once the screws holding it in place are loosened. This adjustability allows the door bottom to fit snugly to the door's threshold.

There is usually a vinyl strip that seals the storm-door bottom to the edge of the threshold, and those sometimes get torn or worn out. Replacements are available but are sometimes difficult to track down. Similarly, the weatherstripping that is attached to the frame and contacts the face of the door as it closes must also be in good condition for the storm door to function as it was designed.

The Right Storm Door

Storm doors can add draft-stopping ability, insulation, and protection to a home's entry doors. The better the installation and the tighter the fit of a storm door, the more effective it will be. Aluminum storm doors have frames that screw to the outside of the door casing. There might be gaps between the frame and the casing, and those can be filled with caulk.

Another area of potential air infiltration is the door bottom. Most storm doors have an adjustable door bottom that can slide up or down once the screws holding it in place are loosened. This adjustability allows the door bottom to fit snugly to the door's threshold.

There is usually a vinyl strip that seals the storm-door bottom to the edge of the threshold, and those sometimes get torn or worn out. Replacements are available but are sometimes difficult to track down. Similarly, the weatherstripping that is attached to the frame and contacts the face of the door as it closes must also be in good condition for the storm door to function as it was designed.

When a storm door is properly sealed and adjusted, it will make the prime door on the house slightly difficult to close. With no other place to go, air trapped between the two will have to rush out around the sides, top, and bottom as the prime door shuts. And when opening the prime door, the storm door should suck in slightly as air is pulled out of the area between the doors. When that happens, you know you've done just about everything that can be done to make a storm door as effective as possible.

Heat and air conditioning can also escape from windows that aren't properly fitted or just old. In the next section, we'll talk about techniques to make your windows more energy efficient.