Front Door: The Importance of Proper Insulation

Your house was built like a sealed envelope in which the windows and doors are thermal bridge contributors. It’s through these openings that 25% of the heat inside your home escapes. 

Therefore, insulating your front door is part of many worthwhile investments you shouldn’t overlook.

How to Prevent Air Drafts—Selecting a Front Door

Old doors weren’t designed with thermal insulation in mind. In fact, instead of patching an air chamber permeated with holes, it’s best to opt for a new door from the get-go. Here is a list of available materials: 

• Fibreglass

• Wood

• Steel

Let’s take a closer look at these doors.

Fibreglass Front Door Thermal Insulation

This is a “sandwich” panelled door. Its core is made of polyurethane foam, giving it a thermal insulation coefficient between R-5 and R-6. Such a door boasts several advantages:

• Doesn’t rust

• Doesn’t warp

• Doesn’t rot

• Barely requires any upkeep

• Energy Star-certified

These doors are typically retailed in two textures: 

• Faux wood

• Smooth surface

With a wide range of colours available, you will undoubtedly find the right pairing for your home.  

Insulating a Wooden Front Door

Now this is a classic front door model. This type of door is especially aesthetic and natural-looking, forever timeless. While the material has appealing insulation properties compared to metal and fibreglass, the door’s insulation still needs improvements.

Since 2010, wooden front doors have entered a new design era—vacuum insulation panels. This latest wooden door design features an insulation panel-filled core, which includes the following components: 

• A nanoporous silica composite core

• A multi-layer aluminum film

• Is vacuum sealed as a whole  

The goal here is straightforward: prevent gas and mould from seeping into the structure. This revolutionary design method ensures a thermal conductivity below 0.003 W/mK. 

What’s the meaning behind that? A 1 cm-thick product is comparable to a 6 cm-thick piece of expanded polystyrene. If you compare it to mineral wool, it’s a 1 to 9 ratio.

Therefore, a wooden front door with a vacuum insulation panel requires only a thickness of 1.29 inches (33 mm), compared to at least 7.63 inches (194 mm) for another insulation option. 

If, at some point in time, you were told that proper insulation cannot be achieved with a wooden front door, rest assured, that's no longer the case.

Thermally Insulated Metal Front Door

Much like the previously detailed front doors, the metal entrance door has an insulated core. Typically, said insulation is polyurethane, but it may also be composed of polystyrene. 

In either case, manufacturers design doors compliant with this standard: CAN/CGSB-82.5-M88. Metal front doors are also retailed with a vinyl coating and a wide range of colours. Some manufacturers even offer customized solutions. 

How to Effectively Insulate Your Front Door Against the Cold

Weatherstripping

Oftentimes, at the first sign of wear, the weatherstripping will be the root cause of substantial heat loss, coupled with uncomfortable air drafts. Another common problem might stem from a faulty weatherstripping installation. The latter will cause the following:

• Water leaks, air drafts, and poor soundproofing

• A thermal bridge

• Deterioration of home finishings

• Condensation, which leads to the building envelope moulding and deteriorating

To ensure that the weatherstripping in place is adequate, the latter must comply with standard CSA A440.4. Said document also details the ideal positioning of the hinges and shims when first installing the door. This allows you to effectively manage the shifting motions caused by the shims secured to the frame’s threshold. 

Draft Guard: Lower Door Edge Insulation

This is probably the simplest and most cost-effective solution there is to insulate your front door. This option is so logical that it most likely dates back to the inception of the front door itself. 

Simply affix this long and narrow device to the lower edge of your front door, effectively blocking any incoming drafts. Not only is this apparatus retailed in all home goods stores, but should you be a bit craft-minded, you can make one yourself using a worn pair of pants and a forgotten pair of socks filled with rice.  

Now, note that some draft-stopper models are known as “twin draft guards,” meaning they’re a double-sided insulation device that’s slipped underneath the door’s lower edge, visible on either side.

If this solution doesn’t strike you as aesthetically beneficial, you can always decide to go for a more straightforward option: a draft baseboard or draft brush secured to the lower edge of your front door. Said options are a lot more subtle than the previously mentioned and equally effective. 

Double-Glazing for Glass-Panelled Front Doors 

The sheer beauty of glazed front doors is unquestionable; however, their lack of insulation properties is a significant drawback. For example, a double-glazed window loses 10 times more heat than a wall. 

Yet, that doesn’t mean you have to draw a line through the idea of having a glass-panelled front door. With Energy Star-certified glazing, you can achieve yearly savings between 7% and 15% on your energy bill.  

To do so, you at least have to opt for double-glazing with a U-value that nears 0.20. Such characteristics are made possible due to the argon gas filling the air space between the two glass panes. Argon gas has low thermal conductivity, with a value of 0.018 W/mK at a temperature of 300 K.

Ultimately, the most efficient double-glazing will result in an average of $500 in savings on your annual energy bill. 

How to Seal a Door for Winter

Over time and daily wear, even the most effectively sealed front door may show signs of draft-related weakening, most notably in the jamb area. Hence the reason why there are alternative solutions specially designed to withstand the coldest of days as well as the warmest ones.

Thermal Door Curtain 

Heat loss can also be mitigated with a thermal insulated curtain. The latter works just as thermal insulated window curtains do. 

It’s a thermal curtain with honeycomb-like, cellular sections, that folds and unfolds like an accordion. Each fabric structure is air-filled to better insulate the door from the rest of the house.

Such a curtain is only worthwhile when used with 3 types of doors:

• Non-insulated front doors

• Glass-panelled front doors

• Incorrectly installed front doors (drafty) 

In fact, when used on a door-window combo, this type of curtain is likely to reduce energy loss by 40% in the winter and mitigate up to 60% of the heat gain during the summertime.

However, the goal behind installing a glass-panelled front door is to allow as much sunlight to seep in, likely rendering the use of a thermal curtain unappealing. 

Seal Gaps and Cracks

The cold draft you feel when nearing your front door most likely originates from the frame or door panel. To tackle this predicament head-on, you can resort to one of the following three weatherstripping options: 

Weatherstripping: A Wintertime Must-Have

Weatherstripping is the simplest way to insulate a front door. It’s a material that ensures constant contact between the door’s edges and the jambs. It can either be:

• Adhesive tape (rubber and V-seal)

• Felt weatherstripping

• Tube-shaped draft blocker (rubber and vinyl) 

• Door sweep weatherstripping (vinyl, felt, plastic)

The vinyl V-seal may be more effective as it also draft-proofs the wall and door through seasonal shrinking and expansion. This is especially common with wood and metal doors. 

However, said solution won’t last a lifetime. With the warping and shifting motions of the front door’s material (especially if it’s made of wood or metal), adjustments are regularly required. 

As for the door’s lower edge, you can opt for the following: 

• A draft stopper with a seal affixed directly to the door

• Full or partial door threshold weatherstripping affixed to the threshold

When browsing for the perfect weatherstripping, focus on combined materials and products retailed with replacement seals.

What is the best front door insulator?

Without a doubt, it’s a door made with a vacuum insulation panel; one that was correctly installed. It’s six times more effective than expanded polystyrene and 9 times better than mineral wood. Vacuum insulation panels are used to insulate:

• Fridges

• Freezers

• Refrigerated trucks

• And more

It’s a super insulator. However, its only caveat is that if the panel is punctured, its vacuum insulation core will fill with air and lose its insulation capacity. So, if you have a habit of nailing your Christmas wreath to your front door, or any other decorative item for that matter, it may be best to opt for another type of front door.

How to Soundproof Your Apartment from Outside Noise

Soundproofing is an entirely different concept from thermal insulation. As we’ve detailed in our floor soundproofing article, proper thermal insulation isn’t necessarily a good soundproofing technique.

Door soundproofing is measured via the Weighted Sound Reduction Index (Rw). Here’s a chart detailing its function:

Sound is a wave which spreads through the path of least resistance. In other words, a front door’s soundproofing quality is entirely dependent on its weak points.

Two factors allow sound to dissipate:

• The door’s density

• Its seal 

In terms of soundproofing capacity, the denser the front door, the better. However, purchasing a hardwood front door with a vacuum insulation panel core, and failing to follow the recommended installation guidelines will be pointless. Sound waves will seep through the gaps running along the jambs, as well as the gap between the door’s lower edge and the threshold. 

How to Soundproof a Front Door

You can count on the following to properly soundproof a front door:

• Soundproof weatherstripping

• Soundproof draft stoppers 

• Caulking/seals 

• Noise cancelling curtains 

Soundproof weatherstripping or draft stoppers do exist, most notably in adhesive tape format. Naturally, if you’ve made this far into the article, you might be asking yourself if said soundproofing technique works with a cylindrical-shaped doorstop. 

In other words: Can you combine thermal insulation and acoustic insulation? The answer is yes, but avoid using several different materials. You can, for example, buy a silicone door bottom adhesive which was designed for both soundproofing and thermal insulation. 

In a way, you can think of a door frame as you would a neoprene adhesive seal draft stopper. When the door is shut, it ensures ideal soundproofing by compression.

You’ve just dealt with your threshold gap problem as well as the space between the door panel and frame. All’s left is the door frame’s surrounding edges. If you were to level your hand with the door frame, chances are you’d feel a small, incoming cold draft.

This is a sure sign of a poorly insulated door frame, one resulting from a worn (dry and cracked) frame or a nonexistent one. Therefore, you must seal the frame with rubber. If, during the process, you spot holes or cracks around your door, fill them with Powerseal expansion foam.

As for noise-cancelling curtains, these are exactly as thermal curtains. When shopping around for such items, you’ll notice upon reading their respective characteristics that they’re excellent soundproofing and acoustic insulators. It’s a bit like a door—the thicker, the better.

Comfort and Savings: Prioritize Front Door Insulation

Having a properly insulated front door is key to ensuring your thermal comfort and guaranteeing an energy-efficient home. Choosing a well-insulated door not only reduces heat loss and sound pollution, but also plays a significant role in lowering your energy bills. When selecting your front door, make sure to factor in the door’s material, closing mechanism, and weatherstripping to optimize insulation efficiency. Hence, a front door is much more than just an aesthetically visual aspect hung to the front of your house, it’s a key component impacting the overall insulation and daily comfort within.