How to Weather Strip a Door

Unless your home as the proper weather stripping and caulking around doors and window, you are losing between 20 and 50% of what you spend a month on heating and cooling your home.[

The good news is that the solutions to correct the situation are fairly low- tech and inexpensive.  The first thing any homeowner needs to do is perform a thorough inspection of all of the doors and windows in your home. Since most windows form a tight seal, this tends to be less of a problem but you do want to make sure you have some type of foam strips at the bottom of each window to form a tight seal.

In most homes, gaps around the doors are the real culprit for most air loss from the home.[2] Nevertheless, while you are weather stripping doors, you might as well verify that there are no issues with the windows in your home.

Before you begin, you should understand that you are never going to solve all air leakage from a home. And in fact, you do not want to because houses need to “breathe” for the health and structure of the home, and consequently, your health.

But closing the gaps around doors and windows will not create an unhealthy vacuum inside, so do not worry about that aspect. You are simply trying to reduce or eliminate the free movement of air out of your home. The house will breathe on its own through other avenues beyond your control.[2]

So with that in mind, here are some things to check before you begin a weather stripping project.

Inspect Your Doors and Windows

To maintain a tight seal on all doors, you need to inspect around the edges on a cold day to see How to Weather Strip a DoorCredit: Opensourceif there are any drafts. If the door already has weather stripping installed, you will probably want to replace it anyway if it is several years old. Normal use of doors tends to fray or loosen any stripping or threshold seals.

If you own an older home, the biggest obstacle in this project might be finding products that can be installed with your door. Older type doors were made without any integral seals, so it is definitively a priority to get this added or replaced if it is worn.

Weatherstripping kits for doors that include the basic strips are available at most home improvement stores. However, once you decide on the type of product you want to use, you might want to consider buying each of those items separately especially if you have multiple exterior doors to reseal.

Before you go out to buy your materials, verify that any draft is not being caused by a loose hinge. To test this, grab the doorknob and pull upward to see if the door moves or wobbles.  Sometimes tightening the hinges can pull the door back inline and reduce gaps. Understand that we are not talking about large gaps typically. But even 1/8 of an inch gap around a door can total to a significant sized hole if it was added up together.

To properly weather seal a door, you are going to need at a minimum two types of products. A long piece of weather stripping for both side and the top of the door and a threshold seal called a door sweep at the bottom.

Basic Materials for WeatherproofingHow to Weather Strip a DoorCredit: Opensource

Most weather stripping products are not very expensive and the cost can be recovered through energy savings in a short period of time.

  • Foam Backer rod used for stuffing in wide cracks in door frames, then caulked over
  • Expandable foam sprayed into large cracks
  • Silcone caulk used to seal any small gaps or joints
  • Garage door gasket used around the door to form a seal
  • Bristle door sweep is typically with a metal edge and rubber seal over the threshold of a door
  • Vinyl door sweep typically with a plastic edge and vinyl seal over the threshold of a door
  • Threshold typically a raised narrow strip of wood placed at on the floor under the door to narrow the gap.

To Summarize the Inspection Process

  • Go to each window and verify that the seams between the house and the window are sealed with caulk. Next, verify that the seams between the house and moldings are sealing with caulk.
  • Check that each window has stripping on the top, bottom and sides. For double-hung windows, make sure there is weather stripping between the two sashes.
  • Verify there are no cracks or loose window panes
  • Check that all exterior doors have weather stripping on both sides and the top, with a floor sweep across the bottom of the threshold.

To Get Started

On a cool day, close and lock all windows and doors and turn off the A/C or furnace. Turn on all fans inside your home such as the bathroom fans and the range hood fan. Next, light a candle  and move it around the doors and windows. If it flickers in one direction or the other, there is an air leak in that area.

To locate the culprit in that area, look at existing weather stripping and caulking. Normally there will be some deterioration such as crumbling or peeling caulk around door frames or torn or hardened foam rubber. Most weather proofing products only have an effective life of a few years so if it has been that long since you replaced it, do so weather you feel or see any drafts.

When caulking outside around door or window frame, if there is a large gap where the caulk has cracked, or if the gap is simply too wide to fill without using an extraordinary amount of caulk, try stuffing foam rubbing strips inside the gap first, then caulk over it. That will fill the gap and give the caulk something to grab and stick to without having to use an entire tube of it.

How to Weatherstrip a Door

Weather Stripping an Entry Door

  1. Adjust the door if is out of alignment by checking the hinges. If the screws are loose or How to Weather Strip a DoorCredit: Opensourcethe wood will not hold the thread, remove the screws and hinge and apply some wood filler and let it harden before reinstalling the screws and tightening the hinges.
  2. Using tin snips or other cutting device, cut any metal or tin strips so that they fit inside the door jamb. Once they are tacked, or slipped, into place, open them slightly to create a tight seal when the door is closed. If you are using vinyl strips, simply remove the tape on the back to expose the adhesive and press tightly to the door jamb, adjusting as necessary. To create a double seal, place tube gaskets with metal or plastic backing on the outside.
  3. For the threshold, measure the width of the door from inside and mark the length on your new floor sweep.

Depending on the type you bought, the installation will be slightly different but nothing major. Some come with adhesive on the back that simply sticks to the bottom on the outside of the door. I do not recommend these, especially if you have carpet inside. They tend to pull off rather easily.

A better option is the kind that screws through a hard backing to the outside of the door. Adjust it accordingly to keep air from leaking under the door. You want a seal against the threshold of the door when it is closed.

Another type of door sweep can be installed on the bottom, but this requires you to remove the door from its hinges in order to screw it in through the bottom. However, some of these also have screw holes on the sides for installation.

Finally, if it is an older door, check to see that there are not any cracks in the wood panels. If so, fill them with wood putty and stain to match the area. You might want to consider adding a storm door on the outside for added insulation.

Final Thoughts

Adding weather stripping to your doors or windows is and quick and easy project that most DIY home owners can do in an afternoon on the weekend. The cost is minimal and it can provide savings on future electric bills that will pay for itself in a matter of months in most situations.

Make the appropriate measurements and dry fit any strips or thresholds before permanently putting them in place.

Finally, do an inspection of your doors and windows every few years and replace the weather strips and make other repairs as needed. If the property is going to be vacant for an extended period of time, be sure to make all of the necessary winterization steps.

M-D Building Products 10116 36-Inch Deluxe Low Threshold with Vinyl Seal
Amazon Price: $27.81 $16.24 Buy Now
(price as of Jun 16, 2015)