insulated garage doors and insulation kits & energy efficiency, savings and comfort

If you only use your garage for car parking and storage, and your garage is detached from your house, the door’s energy performance may not matter. You may not need an insulated garage door.

Otherwise if will be important to avoid overheating and freezing problems, and for comfort and energy savings.

If you are thinking about buying a garage door insulation kit, or buying a new garage door and wondering about its R-value (insulation) and its costs and benefits, consider the following tips.

garage door overheatingThey will help you decide what the best options are.

Garage door insulation: is it worth it?

Garage door insulation can provide significant comfort and energy savings.

Be aware anyway.

Benefits can be huge, but garage door insulation may fall short of your expectations. There are many factors that you should take into consideration: the type of insulation materials, its R-value, its installation, the seals of the door or their exposure to the sun and winds…

A basic tenet to keep in mind:


Costs of new insulated garage doors

New garage doors vary a lot in their insulation value (R-value). And part of the difference of costs can be due to their insulation elements.Insulated garage door R-value
The insulation of a garage door or a garage door insulation kit is given by its R-value; a higher R-value translates into lower energy bills and in some cases lower outside noise... Be aware anyway. The R-value advertised by the manufacturer may be misleading. It doesn’t take into account issues like the quality of the installation of the door, or the type of door, or air leaks, or – in the case of factory-insulated doors – may only represent sections of the door, not the whole door.

The difference between the cost of a cheap uninsulated steel door, and a similar door with a reasonable or good insulation layer can be of, say, $100.

But since insulated doors are typically quality products, which also depends on many factors besides their insulation elements, the cost difference can be much higher.

All depends on what you want, the type of door (steel, aluminum, wood, composite, fiberglass, vinyl) and its style or size.

See: Garage door prices

R-Value of new garage doors

The benefits of insulated garage doors are significant. But that doesn't mean that the insulation value advertised by manufacturers is accurate. On the contrary.

Manufacturers often advertise the R-values of their garage doors: Clopay and Overhead Door advertise an R-value of about R-17 for some of their doors; Waine-Dalton advertises R-15; and so on…

Unfortunately, that’s only true for some central sections of the doors. If we consider the entire door, that’s rather inaccurate. The actual R-values can be 1/2 or 1/3 of the advertised R-values.

And if we consider issues like air leaking – due to poor seals or un-optimized door installation – that becomes even more evident. We should not forget that the performance of a garage door is highly determined by air leakage; it can be more important than the R-value.

Garage door insulation materials (for existing doors)

There is a great variety of insulation kits for existing garage doors. They include inserts, panels, sheets… and materials like 1) foams (polyurethane, polystyrene), 2) fiberglass or other similar insulation product and 3) reflective e-low materials (foils).

The effectiveness and the quality of these materials vary a lot. Many manufacturers overvalue the true R-value and the benefits of their products.

Insulation Kits: Foams or fiberglass?

Typically, foams have a higher R-value (insulation) per inch than fiberglass and other similar products. For the same thickness they are a better choice.

On the other hand, different materials can provide the same thermal insulation, depending on their thickness; in this perspective, fiberglass insulation kits can be as good as foam kits, if sufficiently thick.

The most popular garage insulation kits involve EPS (extruded polystyrene) and fiberglass panels.

Note on high quality foams: prefer UL certified polystyrene or high quality polyurethane.

Best garage door insulation kits: polystyrene or polyurethane?

Polystyrene (even extruded polystyrene) has a lower R-Value than standard polyurethane. You need a thicker polystyrene kit to get the same insulation provided by a polyurethane insulation garage door kit.

When dealing with factory insulated doors, the most important is the R-value of the entire door - which depends on the insulation materials and their thickness, and also on construction details and elements involving the frames and the structural parts of the doors.

In the great majority of cases garage doors haven't the R-values advertised by their vendors; R-values of 15-18 are difficult to achieve, and most doors have R-values below 10-12. Even if there is sections of the door with the advertised insulation, the door as a whole may have a much smaller R-value.

Reflective insulation kits for garage doors: do they work?

Many insulation kits for garage doors are made of reflective insulation materials, that is, metallic foil materials, usually aluminum.

They are designed to prevent heat transfer and are most effective at keeping garages cool in summer and in hot climates, though they may also prevent some heat loss during the heating season.

These materials are light-weight, very strong and very easy to install. They are also cheap materials and are becoming very popular.

It’s difficult to assess the advantages of these products, which in part depends on their quality. But though they may be advantageous to prevent garage overheating, overall they are far less effective than insulation kits made with polystyrene or fiberglass.

DIY garage door insulation kits

Most insulation kits are DIY products. You just have to follow the manufacturer’s instructions.

The kits typically come with their own fastening system, but they do not all provide a quick and secure method to hold the insulation in place.

It may involve the use of tapes, fasteners, clips, adhesives… It depends on the exact type of material.

The difficulty of installation varies, and it may not be as easy or effective as advertised by some manufacturers.   

Garage door insulation kit Customer reviews and Prices

Owens-Corning and Atlas EPS Matador are, currently, the most popular insulation kits for garage doors in the North America. You can see reviews on these and other garage door insulation kits in big retail stores sites (see garage door insulation kits).

Since the kits and the garage doors aren’t being rated by the Energy Star or any other similar program, that’s the easiest way to read customer reviews.

Costs of the most popular insulation kits: $50 - $90 range.

Sealing a garage door can be as important as its insulation

Garage doors can be very leaky. In other words: the seals (the edge seals and the bottom seals) and the quality of the installation are crucial for air-tightness and for the energy efficiency of the garage door. Without them, the insulation-value (R-value) of the door is of little worth.

Bottom line: Insulated garage doors may fall short of expectations. The insulation advertised by door makers can be misleading. Most of the times it only involve sections of the door, and the door seals and a poor door installation render the door insulation rather ineffective.

There aren't mandatory standards for the garage door industry; in the North America, only since January 2009 the DASMA (the Door and Access System Manufacturers Association) has put into effect a program with voluntary standards for garage door manufacturers, involving the R-values of their doors (DASMA TDS-163).

Note: when comparing garage doors - in the USA and Canada - you may look for DASMA TDS-163 certification and independent testing.

Garage door protection ideas: other things that matter besides insulation or sealing

Protect your garage door as much as possible from cold winds or from the sun - in hot climates and during the summer. That’s critical to prevent heat transfer. Landscaping, shading devices, and the shade of trees or bushes – if possible – are very important factors to prevent overheating.

Pay also attention to the color of the door. A light color garage door is an easy way of preventing excess heating.

Energy savings

Garage door insulation (and sealing) can provide comfort.

If your garage is attached to your living space, and there is heat transfer between the garage and the other parts of your house, insulated garage doors (and garage insulation) will also increase the comfort of your living space, and will provide significant energy savings.

Do not undervalue the possible impact of your garage and its door in your home's thermal comfort and your energy bills.


Garage door insulation can be important
- When the garage is heated or air conditioned, and used for activities other than car parking and storage.
- To prevent overheating and freezing problems.
- When the garage is attached to the residential living space, to control heat transfer, that is, to prevent heat loss from the living space during the heating season, and to prevent unwanted heat gains during the summer.




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