Flat roofs are a popular choice for many homes, particularly in modern and minimalist designs. They offer a sleek aesthetic and can provide additional outdoor living space, but like any roofing system, flat roofs come with their own set of considerations. In this blog, we’ll cover the types of flat roofs, common concerns, skylights, waterproofing, and repairs, all from the perspective of a professional tradesman with experience in flat roof installations and maintenance.
What Are Flat Roofs Made Of?
Flat roofs are built using a variety of materials, each offering its own set of advantages and lifespan. The most common materials used in flat roof construction include:
- Felt: Traditionally used, felt roofing is layered to create a watertight membrane. While affordable, felt roofs require regular maintenance and have a shorter lifespan than other materials.
- Rubber (EPDM): EPDM is a popular choice for flat roofs due to its flexibility and durability. Rubber roofs can last up to 30 years with proper maintenance and offer excellent resistance to UV rays and weathering.
- Liquid Rubber: This is a liquid-applied membrane that creates a seamless, waterproof barrier. It’s ideal for covering complex roof shapes and for repairs.
- GRP (Fiberglass): GRP flat roofs are extremely durable and lightweight. Once installed, they require very little maintenance and are highly resistant to cracks and leaks.
- PVC: PVC roofing is another popular option for flat roofs. It is highly durable and reflective, making it a good option for energy efficiency.
Types of Flat Roofs
There are several types of flat roofs, each with its own construction method and suitability depending on the building’s design and location:
- Warm Flat Roof: This type of roof places insulation above the structural deck, keeping the internal building warm without the need for additional insulation layers inside.
- Cold Flat Roof: Here, insulation is placed beneath the roof deck, which means the roof itself remains exposed to the external temperature. This is a less efficient method and can lead to condensation issues if not properly ventilated.
- Inverted Flat Roof: This is an improvement on the warm roof system, where the waterproofing layer is beneath the insulation, protecting it from damage and temperature fluctuations.
How Long Do Flat Roofs Last?
The lifespan of a flat roof largely depends on the materials used and the quality of installation. Here’s a rough estimate based on materials:
- Felt Roofs: 10 to 20 years with proper maintenance.
- EPDM Rubber Roofs: 50 years and upwards.
- GRP Fiberglass Roofs: 20 to 30 years.
- PVC Roofs: Around 20 to 30 years.
Types of Skylights for Flat Roofs
Skylights are a great addition to flat roofs, providing natural light and ventilation. Here are a few common types:
- Fixed Skylights: These skylights do not open but allow natural light to flood into the space below. They’re a simple and cost-effective option.
- Opening Skylights: These are ideal if you need ventilation as well as light. Some models can be manually or electronically opened to improve airflow.
- Velux Rooflights: Velux is a trusted name in skylights, and they offer a range of rooflights specifically designed for flat roofs. They can be fixed or opening and come in various sizes and finishes.
Best Waterproof Paint and Roof Sealant for Flat Roofs
One of the best ways to protect a flat roof is by applying waterproof paint or a roof sealant. Here are some of the best options:
- Liquid Rubber: This is a top choice for waterproofing flat roofs. It’s easy to apply and creates a seamless, flexible membrane that protects against water ingress.
- Acrylic Roof Coatings: Acrylic-based waterproof paints are also effective for flat roofs, providing a reflective surface that reduces heat build-up.
- Bitumen-Based Paint: Ideal for felt and asphalt roofs, bitumen-based waterproof paint provides a strong, waterproof barrier and is easy to apply.
Insulation for Flat Roofs
Proper insulation is crucial for flat roofs, especially in colder climates like the UK. Insulating a flat roof can be done in a couple of ways:
- Warm Roof Insulation: Insulation is placed above the roof deck, preventing heat loss and improving energy efficiency.
- Cold Roof Insulation: Insulation is placed beneath the roof deck, but this can lead to condensation issues if not properly ventilated.
A well-insulated flat roof can significantly reduce energy bills and improve the comfort of your home.
Is Rubber Roofing Better Than Felt?
In our experience, rubber roofing (EPDM) is a much better option than felt for flat roofs. It’s more durable, flexible, and requires less maintenance. Rubber roofs can last up to 50 years plus, whereas felt typically needs replacing within 10 to 20 years. Rubber is also less prone to tearing and cracking, making it more resistant to the elements.
Conclusion
Flat roofs, when properly installed and maintained, are a practical and stylish option for homes. From choosing the right materials and skylights to ensuring waterproofing and insulation, there are plenty of ways to optimize a flat roof for long-term durability. If you have any questions about flat roof installation or repairs, don’t hesitate to reach out to one of our professional tradesmen. We’re always here to help keep your home protected and looking great!