This door bottom automatically moves downward when the door closes, forcing the weather stripping against the door threshold and creating a tighter seal. This is ideal when there is tall, plush carpeting by the door.
Photo courtesy of Pemko Manufacturing
Question: My front door is wood with a window, and my back door is metal. Neither is efficient nor airtight, but I can’t afford to replace them. How can I improve their efficiency?
Answer: Energy losses from inefficient entry doors can account for a significant portion of your monthly utility bills. When leaky doors create cold drafts, people tend to set the thermostat higher, wasting even more energy.
You can improve the efficiency of old doors, but don’t eliminate the possibility of installing new ones. The costs of some well-insulated steel and fiberglass doors, especially those for the back door without glass, are very reasonable. A pre-hung door in its own frame is not difficult to install yourself.
Before deciding, carefully inspect your old doors. If they are in very bad condition, it will be difficult to improve their efficiency by a meaningful amount.
For the wood door, make sure it is not rotting. Then place a long straightedge across the door to see if it is badly warped.
With metal doors, the most common problem is rust. The first place to check is along the bottom by the weather stripping on either side. Rainwater tends to collect there. If you can figure out why, correct that problem first. Any small holes that have rusted through can be repaired. Clean out as much rust as possible, fill the holes with car body filler, and then paint.
If your doors are reasonably sound, check for air leaks. At night, have someone shine a flashlight from outdoors around the seals and see if the light shows indoors. This will highlight significant leaks. On a windy day, move a stick of lighted incense around the seals and watch the trail of smoke to find minor leaky areas. Self-adhesive weather stripping around the door frame will help seal leaks. On double doors, check the astragal—the raised half-round overlap where pairs of doors meet that acts as a seal between them.
Often with wood doors, especially ones with compression weather stripping, the main problem is simply that the latch plate is not holding the door tightly closed against the weather stripping.
One solution is to reposition the latch plate. This will require filling in the old screw holes and drilling new ones. Chisel away some of the wood in the recess for the new latch-plate position. Another option is to install an adjustable latch plate that can be repositioned for summer and winter, when the door and frame expand and contract from seasonal temperatures and humidity.
Steel doors should feature magnetic weather stripping, so the seal shouldn’t be a major issue, because the weather stripping is drawn against the door edge. Just make sure the surface of the door and the weather stripping are clean and smooth.
If door hinges and pins are worn, the door may not hang square in its opening and will not seal properly. You can replace them, but since there are many different sizes of hinges, take an old one to the store to get an exact match.
The seals on the bottom of older doors, against the floor threshold, get worn and can be replaced. You can also create a tighter seal by adjusting the floor threshold higher, using the height-adjustment screws across the threshold. After years of use, they may be filled with dirt. Poke around to find them. If the seal itself is bad, you can install a generic replacement seal.
Another option is an add-on retractable threshold seal. This is especially effective where there is carpeting on the floor by the door. The threshold seal is mounted on the lower door edge. When the door opens, a pin against the door frame is released and the seal automatically lifts to clear the carpeting. It is easy to install and adjust.
Send questions to Energy Q&A.
_____
Get More
The following companies offer door-improvement products:
Duck Brand, (800) 321-0253
M-D Building Products, (800) 654-8454
Pemko Manufacturing, (800) 824-3018
Thermwell, (800) 299-5700