When it comes to exterior doors, two of the most popular materials are fiberglass and steel. Both have great benefits and are great choices for people who want to improve the insulation and energy efficiency of their homes or businesses. In this article, we’ll look at each material in more detail to help you decide which one is best for you. 

Comparison of Insulation and Energy Efficiency

When it comes to insulation and energy efficiency, it can be difficult to determine which option is best for your home. Both fiberglass doors and steel doors have their pros and cons. Here, we’ll look at how well fiberglass and steel exterior doors from reputable companies like STL Windows and Doors insulate and save energy.

Fiberglass doors are a great choice when it comes to insulation. This material is a great insulator, which means that it can keep your home’s temperature stable and comfortable all year long.

Fiberglass is a great insulator because it has extremely low thermal conductivity. This makes it harder for heat or cold to leave or come into your home through the door. This helps keep your home at a consistent temperature, regardless of the temperature outside.

Fiberglass doors also offer superior soundproofing. This is because the material is very good at absorbing sound waves and stopping them from getting into your house. This means that you can live in peace and quiet at home and save money on your energy bills.

Fiberglass is also a great choice because it saves energy. Fiberglass doors are less likely to let air out than doors made of other materials, which means you can save money on energy costs by using them. Also, they don’t rot or rust, so they won’t need much upkeep.

Steel exterior doors are also a good choice for energy efficiency and insulation. Steel is a good conductor of heat and cold, which means it can help keep the temperature in your home stable. It is also very long-lasting, so it won’t need a lot of care.

Steel doors, on the other hand, are not as good as fiberglass doors when it comes to saving energy. Steel doors can let air out and make it take more energy to keep the temperature in your home at a steady, comfortable level.

Maintenance tips for Fiberglass and Steel Doors

Fiberglass Doors:

  1. Clean regularly: Regularly cleaning your fiberglass door is the key to keeping it looking great. Use a soft cloth and mild detergent to get rid of dirt and dust, then rinse with clean water and dry with a clean cloth.

    2. Check for wear and tear: Inspect your door for signs of wear, such as scratches and chips, and repair them as soon as possible to maintain the door’s aesthetic appeal.

    3. Repaint, if necessary: If the paint on your fiberglass door has faded, you can repaint it to restore its original look. Choose a paint that is made just for fiberglass and follow the directions from the manufacturer for the best results.

    4. Re-caulk, if necessary: If the caulk around your door is cracking or peeling, you should re-caulk it to prevent water damage. Use caulk made for fiberglass and follow the instructions from the manufacturer for the best results.

    5. Replace weatherstripping: If the weatherstripping around your door is cracked or worn, it’s time to replace it. Choose weatherstripping made just for fiberglass doors and follow the instructions from the manufacturer for the best results.

    Steel Doors:

    • Inspect your steel door for signs of rust or corrosion regularly. If you do find any, use something to get rid of rust to clean it up.

    • Steel doors should also be cleaned regularly with a soft cloth and a mild detergent.

    • If you’re painting your steel door, use a paint specifically formulated for steel. This will keep rust and corrosion from happening.

  • To prevent rust, make sure to keep your steel door lubricated with WD-40 or a similar product.


In conclusion, both steel and fiberglass exterior doors are good at keeping heat in and cold air out. However, fiberglass provides better insulation than steel and is also more energy efficient. So, if you have to choose between the two, fiberglass is the better choice for better insulation and saving energy. You can also know more about fiberglass and steel exterior doors by simply clicking on this url.