Pros & Cons of Flat Roofs

Many people refer to these roofs as “low slope” over flat. This is because all roofs must have sloping to allow for drainage. Taos Pueblo in
New Mexico is likely the earliest flat roof featured in North America and was constructed sometime in the mid-8th century and remains occupied
even today.

There are three different categories of flat roofs:

• Membrane or single-ply: A single layer of waterproofing membrane is laid and adhered to the top of the insulation board. This may be
  held down using a ballast, masonry pavers, or river rocks.
• Built-up Roofing (BUR): Before bitumen and membrane roofing innovations, BUR roofing systems were the most common flat roofs
  on the market. This technique uses multiple layers ( insulation board layers, multiple layers of tar and asphalt alternated with roofing felt,
  and rocks or gravel.
• Modified Bitumen Roofing: As you can imagine, built-up roofs are heavy and require added structural support. Modified bitumen
  roofing systems were the answer, using a flexible asphalt-based coating with a mineral coat on the top. It achieves the waterproofing of
  BUR without the smell, heat, mess, and weight. Sheets of modified bitumen roofing are rolled out in three-foot-wide sheets, layered,
  and adhered to the back using the “torch down” method.

As with all roofing systems, performance is related to the quality of materials you select, the conditions it’s performing in, and the maintenance
you choose to do along the way.

Here are some of the pros of having a flat roof design:

Cost-effective: Fewer materials and less labor mean the first-time costs are lower than other roofing systems.

Maintenance & Repair: Lower pitch means a safer working environment and easier maneuvering for solar installers, HVAC installers, and roofing contractors.

Green Design: Low slope roofs are perfect for incorporating grass, native flowers, and plants that can insulate your home and minimize energy costs. These systems can usually be installed on roofs up to a rise of three feet for every 12 feet in length.

Skylights / Solar Tubes: Without having to worry about attic space, flat roof designs are ideal for skylights and solar tubes. These let in natural light and help you conserve energy and save money.

Here are some of the cons of a flat roof design:

Lifetime Costs: Despite the innovation, flat roofs still have a shorter lifespan than pitched roofs. Owners tend to find themselves in more frequent need of repairs and roof replacement than they would with a sloped roof.

Maintenance: These roofs require more maintenance, mainly in the form of waterproofing. These maintenance visits can add up quickly over the lifespan of your roof. Roofs should be looked at once a year to check penetrations (electrical, plumbing, chimney, skylights) as they are most vulnerable to leaks.

Drainage: A reduced slope means draining water from your roof takes longer. This could lead to the roof being exposed to standing water. As a result, homeowners are likely to experience leaks, leading to water damage if they aren’t resolved quickly.

As with all roofing systems, there are pros and cons. Ultimately, it will depend on your budget, preference, the weather these systems are installed in, and the abilities and reliability of your roofing contractor. You can depend on McLaren Roofing for your low slope needs. Contact us here for more information.