Contemporary architecture emphasizes streamlined form and functionality. Common features of modern styles include clean lines, low horizontal structures, and long, flat roofs with large overhangs.

What is a flat roof? 

From the ground, a flat roof looks flat, but in fact, it has a very low slope to allow drainage. It is designed as one continuous surface, allowing it to hold standing water for a limited time before it runs off. There are a few differnet types of flat roof systems.

Single-Ply Roofing

Single-ply roofing, also known as membrane roofing, consists of a layer of insulation board topped with sheets of rubber or plastic material (the membrane). This membrane can be loose-laid and held in place with pavers, or it can be glued to the insulation layer. Single-ply flat roof systems are typically simple and inexpensive, and leaks are rare. If the membrane is punctured, however, leaks can occur.

Built-Up Roofing

Before membrane roofing was developed, built-up roofing (BUR) was the most common type of flat roof. This system consists of many layers: a bottom layer of insulation, multiple layers on top of tar or asphalt alternated with roofing felt, and then a top layer of gravel. Due to the multiple materials and layers used in BUR systems, the roof is thick, tough, and very resistant to damage. If considering a BUR system, remember that installation is very labor-intensive and slow. Because this type of roofing is not flexible in colder temperatures, installation in cold weather makes it more susceptible to damage.

Modified Bitumen Roofing

Modified bitumen roofing (MBR) was developed as a lightweight alternative to BUR. MBR systems are created with flexible material (usually asphalt based) with a mineral top coating, making it similar to traditional asphalt shingles. It comes in rolled sheets that are unrolled on top of a base membrane. MBR systems are easier to install than BUR, which can save on labor costs and reduce errors, and it is much more flexible at lower temperatures. However, it can be less attractive than MUR or membrane roofs, so it might not be the best choice if you’re prioritizing aesthetics.

How do you properly care for a flat roof? 

It is very important to regularly maintain a flat roof, and luckily, it can be simple. The best thing to do is consistently inspect your flat roof after every severe weather event and before each season change. Regular roof inspections enable you to address small problems before they cause more extensive damage.

When inspecting a flat roof, remove any debris, such as leaves and branches, that may have fallen onto it, and maintain landscaping so trees don’t hang over the roof. This is particularly important during the colder months. Then, check the drainage system to ensure it is working efficiently to prevent water damage.

When is it time to repair or replace a flat roof? 

A properly installed and maintained flat roof can last 20–25 years. If you notice issues before then, however, be sure to have a roofing professional assess the need for repair or replacement.

• High energy bills can indicate your flat roof needs attention. This is because high quality roofing material helps conserve energy. If it becomes damaged or worn, it can no longer insulate properly.
• Water damage, which can show up as discoloration or mold, is an important warning sign. You should never ignore a water leak, even if it appears small. If a leak is allowed to continue, the roof can suffer major water damage. Regularly inspect the ceiling and roof for signs of water infiltration, and check metal flashing and vents to ensure they’re not lifting up from the roof, missing, or damaged.
• If the roof membrane is bubbling or cracking or you notice that the very top layer of the roof looks damaged in any way, it is likely time for a replacement. Severe weather can also leave gouges or dents on your flat roof that can lead to structural damage if not repaired promptly.

Pacific Sheet Metal installs and repairs a variety of roofing materials for Colorado homes and businesses. For more advice on maintaining a flat roof, subscribe to our blog today!