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Front doors, and all doors, are common areas in a home's exterior that let in unwanted outside temperature. Whether it is hot summers or cold winters, you wonder how to insulate a wooden front door to keep those seasons out of the house. In this post, we combine industry professional knowledge and up-to-date research to thoroughly answer your question.
Insulating a wooden front door requires a combination of direct insulation and air sealing. Because the front door is centrally visible and highly trafficked, all of these recommendations do not change the look of the front door. Ways to insulate a wooden front door include the following:
- Improve weatherstripping
- Improve door sweep
- Spray foam frame gaps
- Caulk cracks
- Install a storm door
- Add window film
Keep reading the rest of this post for details on how to accomplish all of the above recommendations. By taking these steps, your wooden front door will be much more resistant to the transfer of hot or cold from outside the house. To conclude, we answer a few related questions.
How to Insulate a Wooden Front Door
While it is possible to fill the door frame of your wooden front door with insulation, this is an unattractive option that renders the door unusable. Instead, take the following steps to help insulate your wooden front door.
This work is necessary because, unlike the main wall assembly, wooden doors are not easy to insulate with cheap conventional insulation such as fiberglass batts or cellulose.
The most important step to insulating your wood door is weatherstripping. This is rubber or other pliable material that rims your door frame. Often, this material loses effectiveness over time or was not properly installed in the first place.
Things that damage weatherstripping include pets, use, moving furniture, and age. Further, as your home settles, weatherstripping that once sealed your door can lose effectiveness. Generally, you can see if the weatherstripping is damaged by noticing tears, frayed areas and if you can see the light or feel the breeze around your door.
Installing new weatherstripping is relatively easy and can usually be done by the home handyman. Alternatively, you can hire an expert to install this product at a reasonable cost. Weatherstripping one door generally runs about $100.
How do you weatherstrip a door?
How you weatherstrip a door depends on what type of weatherstripping you plan on installing. However, no matter the style, the first step is to remove the old weatherstripping. Often this is as simple as pulling the weatherstripping out of the built-in weatherstrip slot, but sometimes you will need to use a drill to remove old weatherstripping.
Then, you want to take your new weatherstripping and insert it into the provided slot (or stick it on, or screw it on). At the corners, you will need to cut one of the pieces of weatherstripping at a 45-degree angle in order for everything to fit tightly.
There are tons of resources available on how to accomplish this task including the helpful video below:
Improve Door Sweep
The door sweep is the larger piece of material that connects the bottom of the door to the bottom of the door jamb. It is called a sweep because it sweeps across the ground as you open and close the door.
Like weatherstripping, this material does not last forever and often gets damaged over time. To check your door sweep, simply get on your hands and knees and take a look. Fraying, incomplete rubber, and any light are all signs that you need a new sweep.
How do you add a new door sweep?
The trickiest part of adding some door sweeps is that to do it, you must remove the door. After you carefully take the door off the hinges and set it on a working surface - you should be able to screw or stick the new sweep onto the bottom of the door.
Some door sweeps stick-on or slide onto your doors, however, these styles are not as long-lasting. When purchasing a new sweep, make sure to get one that will fill the space under your door. The age and construction of your home can greatly influence how large this space is.
Spray Foam Frame Gaps
Of all the steps listed here, this one takes the most construction and home improvement know-how. To perform this step, you will first need to remove the door trim, known as casing, that covers the frame to the wall cladding.
If done carefully, you can usually pull this material off without marring the walls or breaking the casing. This is important because you will want to replace the casing back where you found it when done. You can either remove the interior or exterior casing - choose whichever looks easier.
The best way to pull casing nails is to use a nail puller and to pull them through the wood --don't pound them out and use a claw to pull because this will mark the clean face of the trim.
Often, contractors will not insulate the gap around the door frame, once you have removed the casing trim you will be able to check if this was done properly. If there is no insulation in this gap, the easiest solution is to use canned spray foam.
How to Use Canned Spray Foam?
All you do is follow the directions on the foam can, and carefully fill the gap between the door frame and wall framing. Be sure to set something on the ground before working with this product. Spray foam is very hard to clean once it has made contact with basically anything.
At first, only spray a small amount of foam out of the nozzle until you get a feel for how much the product expands. It is very easy to overfill the gap which can cause a huge mess.
Once complete, and once you have let the foam dry, use finish nails to reattach the trim exactly as it originally was installed. Often, you can even reuse the old nail holes during this process.
The next step to insulating your wooden door is to caulk any cracks around the door. Specifically, you will want to caulk areas where air might be able to move from outside to inside. So as not to caulk your door closed, only caulk crack in the door frame and door trim not between the door and the frame.
Simply draw a bead of caulk along the crack. This process takes a little finesse but becomes easier with practice. Once done, use your finger or a caulk tool to smooth the bead out. Make sure you have a caulk gun if you plan on using a standard caulk tube.
Install a Storm Door
Any obstruction between inside and outside will help to insulate your wooden front door. Storm doors are essentially a second door that opens out, instead of in, and are attached on the very outside of your door frame.
Before buying a storm door, make sure to carefully measure your door frame for fit. Generally, all purchased storm doors come with the directions and hardware needed for installation. So, once you have purchased the door, follow the directions included to perform the installation.
As an added bonus, many storm doors come with different inserts that match the season. That is to say, you can put glass or solid material in the door for the winter and a screen into the storm door for the summer.
Add Window Insulation
Window insulation is only applicable for wooden front doors that have a glass window insert. This film material adds another layer of protection that will help insulate your door window from the elements.
To install, first carefully cut the material to fit around the window in question. Then, following the included directions stick the film to your window frame. Sometimes, it will work better if you use a hairdryer to heat up the edges of the window insulation.
What makes a door energy efficient?
A door is made energy-efficient if it stops the movement of both heat and air from one side to the other. Taking the steps outlined in this post all help make your door energy efficient - mostly by decreasing the ability of air to move from one side of your door to the other.
Another factor that influences a door's energy efficiency is the door material itself. For instance, a solid wood door does a much better job at stopping heat transfer than a hollow-core wood door. Some doors are metal on the outside which encases insulation on the inside.
Why do doors swell in winter?
Doors do not only swell per se in the winter, but they also minutely change shape. What happens is the difference between the outside and inside relative humidity and total moisture content in the air.
Cold outside air can hold almost no moisture while the warmer inside air has a lot more moisture. This means that the inside of the door will soak up more moisture compared to the outside of the door. This differential often changes the shape of the door to make it difficult to close and/or latch.
How do you stop a wooden door from swelling?
One way to stop a wooden door from swelling and changing shape is to reduce indoor humidity. This can be accomplished through dehumidifying products.
What is the U factor for a solid wood door?
Most doors are about 1-3/4 inches thick. For solid wood doors of this thickness, you can expect a U-value of about 0.33. This corresponds to an R-value of 3.03. This is much worse than the R-value of a typical wall assembly which ranges from R15 to R-23.
In this post, we answered the question of how to insulate a wooden front door. We include several techniques and brief directions for how to accomplish each one. To conclude, we answered several related questions. Good luck!
Here are some useful links to other HVAC Seer articles on insulating doors and windows: