There are differences in the types of garage door insulation used in the different types of doors. Most use either polystyrene or polyurethane and both products are safe to use as insulating materials. Polystyrene comes in a solid state and is molded to suit the needs of the garage door. This product is preferred by many manufacturers due to its durability and performance in the door. Polyurethane is a foam that is applied through an automated system and fills every possible space in between the panels of the garage door.
Polyurethane may be a better insulation, resulting in a slightly higher insulating value, but with this type of insulation, manufacturers often advise buyers to choose a dark color door if the door will be exposed to long periods of sunlight. If you choose a door that does have polystyrene as the insulator, the gluing process is very important to ensure that the door does not become defective. When contact cement is used the panels become more resistant to delaminating, but the panels in the door should have brackets to fasten inner and outer layers securely to prevent the insulation from coming out.
The energy efficiency of the garage door depends on the insulation, however weather stripping also plays a huge part in ensuring that cold air does not get in around the bottom of the door and the heat you have in the garage stays there. A double lip weather stripping takes on the shape of the door and helps to seal the door to the floor, even if it is uneven.
Insulation in a garage door can help to keep the temperatures inside to reach below freezing even if the temperatures outside dip below the freezing point. This makes it much easier to start your car on cold winter mornings and you don’t need to have a heating block.