If you felt a draft inside your home even though your heater was working overtime, chances are you had cold air leaking into your home from small gaps and cracks around your doors as well as windows. 

These air leaks will make your HVAC system work harder all through the year. Your air conditioner will probably be on full blast through the summer, while warm air comes into your home and cool air escapes through these cracks. In the winters, the opposite happens. While your home’s furnace warms up the building, warm air will escape and make way for cold air.

This extra load on your HVAC system is not only unhealthy for it, it will also increase your home’s heating and cooling costs considerably. However, it is fairly simple to seal air leaks around your doors and windows. Most of these home improvements require affordable as well as easy-to-install materials such as caulk and weatherstripping.

However, keep in mind before you begin insulating your door against leaks consult an HVAC technician and make sure you’re sealing these gaps will not affect the ventilation, and in turn, the indoor air quality of your home. 

In this short read, we’re going to talk about how to stop air from leaking around a door.

Three ways to detect air leaks

Blackout the room

Use blackout curtains on the doors and windows to completely darken the room you think needs the treatment. If you see any light leaking through the corners or from under the door or the windows, rest assured that is where your draft is coming from.

Check the caulk

caulking a door

The purpose of caulking is to seal off any gaps in door and window frames. If you see that the caulking around the door frame is damaged, that is likely the reason your home is drafty. 

The smoke test

For this test to work, first, use a large exhaust fan to suck out all the stale air from the room. Then, turn off all combustible appliances and make sure all the doors and windows are tightly closed.

Then, light an incense stick, a thin piece of tissue paper, or a candle and take the flame close to the border of the doors and windows. If the smoke from the source either blows into the room or is sucked out, it is indicative of a leak around that frame. 

Three air sealing tricks

Door draft stoppers

door draft stoppers

This is a makeshift arrangement at best. Door draft stoppers can be placed at the inner base of the door to create a temporary draft barrier.

Other than acting as a draft barrier, door draft stoppers also block out outside noise to a certain extent. These stoppers are made out of materials such as plastic, Styrofoam, silicone, or fabric. 


Weatherstripping or the process of installing weather strips around doors and windows to insulate them is a more permanent solution. 

Also known as door sweeps, weatherstrips are made from a variety of materials, ranging from wood, felt, rubber and vinyl to metals like aluminum and brass.

The most durable weather strips are called compression weather strips and are made of aluminum, wood, or vinyl with a flexible vinyl bulb.


If the caulk around the door has worn out over time, recaulking it is another effective way to seal those air gaps.

This method is best suited for gaps less than ¼ inch wide. All you need is a tube of external caulk and a caulk gun. 

Before you begin recaulking, remove old paint and old caulk from the area. Wipe it clean with a damp rag and let it dry completely before you begin.

Once you’ve recaulked the area, remember that it will take 24 hours for it to cure. 

Home insulation: How to stop air from leaking around a door was last modified: October 14th, 2022 by Narayan Shrouthy
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Recaulking gives the sense of calm of a successful repair