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Insulated exterior door

Did you know that apart from the windows, the entrance door is one of the main sources of heat loss in your house? Sealing doors is not difficult.

When drafts and cold from outside enter the house or apartment, you first have to check which gap the wind is blowing from – especially in old buildings, where older doors are the norm.

At this point, we present several methods of door sealing, with which you can quickly and without much effort block out drafts, noise, and bad odors. Effect guaranteed!

What factors influence the thermal insulating properties of a door?

When deciding which material should be selected for an energy-efficient entrance door, it is necessary to take into account various factors that affect the thermal insulation properties of a door.

Factors you should not overlook:

  • The thickness of the frame.
  • The thickness of the door leaf.
  • Installed insulating materials in the door leaf.
  • Thermal transmittance of the selected door, the number of seals, and the seal at the threshold between the leaf and the frame and glass insulation.

Why is energy-saving important?

Good thermal insulation of front doors and windows should be a central part of construction planning for both old building renovations and new buildings. Therefore, not only the insulation of walls, ceilings, and the roof is sufficient for the overall energy efficiency of the building. One should also take into account the front door.

In addition to cost savings, good house insulation also reduces greenhouse gas emissions and thus contributes to environmental protection. Heating costs in buildings with old and dilapidated front doors and windows increase, especially in the winter months. More energy is lost through the windows and doors due to poor insulation and sealing than through an uninsulated facade. Replacing the entrance door can reduce energy costs by up to 7%.

Specify the construction material for the exterior door

In most cases, doors are made from one of the four following materials. Each material has its own pros and cons. By selecting the wrong material, you could end up with a door that insulates poorly (or well).

  • Steel: A steel structure is durable and low-maintenance because it is built to withstand impacts. Multi-layered doors can be created with this flexible and versatile insulation wrap, as it can quickly wrap around foam or vinyl insulation layers.
  • Aluminum: Are you looking to make your main entrance more modern? Then aluminum is the right choice. But aluminum does not provide as good insulation as steel due to its thinner thickness.
  • Glass: No exterior door made entirely of glass can be found at your local hardware store. That’s true. The purpose of having metal frames for these glass doors is to increase their insulating properties.
  • Wood: There is no doubt that wooden doors are the most preferred choice thanks to their traditional appearance, strong appeal, and availability in conservative as well as modern colors. And they provide a decent amount of insulation.

How to find leaks from doors?

Then it is a matter of tracking down the gaps. Leaky joints can occur, for example, at windows that have not been properly sealed. In the case of doors, the draft does not necessarily have to come from the outer doors, but can also pass under the inner doors, for example, if there are different temperatures in the rooms.

It is not always immediately clear where the draught in the house and apartment comes from. To find out where the leak is, first look at all sides of the door and look for large gaps in the floor, ceiling, or door frame. Also, open the door to check if there is any damage to the seal anywhere.

In many cases, you can at least feel the direction from which the draft is coming. If this is not the case, there is a simple remedy: place a burning candle or a smoldering incense stick and pay attention to how the smoke or flame behaves. This will help you track down the source of the draft and find out exactly where you need to seal your doors.

What you can use to insulate an exterior door

Suptikes Pack Door Draft Stopper

Suptikes 2 Pack Door Draft Stopper
  • Fit Gaps up to 1 inch.
  • Easy to install.
  • For various types of doors or windows.

 4,8 Rating

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The door bottom seal designed by 2 layers of sealer, stop the noise, keep your room cozy and quiet! It is widely used in various types of doors or windows like frameless sliding doors, glass doors, sliding doors, wood doors, cupboards, wardrobes, furniture and shower room, etc.  Just measure the width of your door, cut to size, peel the backing off the adhesive and stick it to the door! Also preheat the strip with a hairdryer in cold winter to help it stick well.

VITAM AMO Weather Stripping Seal Strip for Doors

Weather Stripping Seal Strip for Doors
  • It seals a large gap from 5/16’’ to 35/64’’.
  • Special soundproof holes design.
  • It’s made of a flexible material.

 4,8 Rating

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With a general temperature rating of -140°F to +400°F, our seal strips are ideal for numerous applications. It’s made of a flexible material and will not freeze or crack under extreme temperatures. Unlike other sealing strips, VITAM AMO sealing strip has a special design with multi holes. The multi holes always reduce the sound propagation on both sides of the door, and they absorb a portion of the sound waves to reduce the noise.

Foam Insulation Tape Self Adhesive

Foam Insulation Tape Self Adhesive
  • Toxic-free.
  • Can be used from -50 °C to 150 °C.
  • Strong adhesive backing.

 4,8 Rating

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Has excellent sealing and resistance to deformation feature. High-Density Foam Tape —Weatherproof, oil resistance, resistant to corrosion, dustproof, shock-absorbing, buffering, sealing, flame retardant, shock-absorbing, sound and heat insulation, anti-skidding, and insulating.

Ways to Insulate the Door

One of the best ways to check for air leaks is to light a scented stick or candle and go around the door jamb. You will quickly find gaps. The method of insulation you should use will depend on the model of your door as well as the existing glass surfaces.

Foam seals for doors

Foam gaskets allow sealing even larger gaps of up to two centimeters on doors. They also act against sound and odors. However, for foam double seals, the door dimensions are crucial: the door should be no wider than one meter and no thicker than about 4.5 centimeters. Foam door seals also do not cost the world and are available online or in hardware stores.

ways to insulate the door

Rubber sealing strips

If the gap is not at the bottom, but between the door leaf and the frame, sealing strips help against drafts. Rubber sealing strips are suitable for small gaps between 1 and 5 millimeters. However, if the gap is not the same size in all places – and this often happens – problems can arise when closing the door. Nevertheless, sealing strips are a cheap solution and can be bought in stores for a few euros.


Check for cracks or gaps in the walls around the door and at the line between the door and the walls. Then remove any residue from previous work and carefully seal the holes.

Insulate exterior door glass

If part of your door has a door window, you can insulate it with the same insulating kit you use for windows. Easy and quick to apply on the outside of the door.

Make sure the door is clean before using the tape, and place it on the grill between the windows if there is enough room. This way the film will get extra support. Once you glue and dry this layer, it will be dense and barely noticeable.

How to Insulate Windows and Doors – Video

FAQ - Insulating the Exterior Door for your Home

❓ How thick is an exterior door?

Exterior doors are often the most visible parts of a house and, like interior doors, are available in standard sizes. They range in width from 2 feet to more than 3 feet, and in height from 6 feet, 8 inches to more than 8 feet. Standard thickness is 1 3/4 inches.

❓ Should a door sweep touch the floor?

This long strip of metal is surface mounted to the bottom of the door. Ideally, the sweep should be installed, so that it comes in contact with the bevel on the threshold but where the sweep will not touch the flooring material (i.e. carpet, tile) as the door swings open and closed.

❓ How to fill the gap under my front door threshold?

If you’re wondering what to put under a door threshold to fill the gap, then you can use materials such as grout, cork, rubber, wood or form. If you have trouble keeping the heat in or the cold out, a drafty door is likely the culprit.

Max Welder

Max Welder

Hi! I'm Max Welder ( I always wanted to work with my own hands, repair something, do things. Now I combine my knowledge with computers and my own knowledge in the field of mechanics in order to understand which tools I like the most. I hope to convey some knowledge and experience.

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