Flat roofs are popular in both apartment buildings and businesses. They’re most commonly used on large structures like outbuildings. Usually made of synthetic rubber and asphalt, this type of roofing isn’t actually flat but sloped between ¼ and ½ an inch per foot to drain water efficiently.
Are you considering putting a flat roof on your new building? Let’s consider their pros and cons before you make the final decision.
Flat Roofing: Advantages and Disadvantages
Are you considering flat roofing for your home or office? It’s important to understand its pros and cons, but first let’s understand its types.
Types of Flat Roofing
There are three main types of flat roofing: built-up roofing, rubber membrane and modified bitumen.
- Built-Up Roofing (BUR): Before the membrane and modified bitumen varieties were introduced, this was one of the most common types of flat roofing. This affordable roofing system consists of a bottom layer or two of insulation board and many intermediate ones of asphalt or tar alternated with roofing felt. The top layer is composed of gravel.
- Rubber Membrane: A rubber membrane roof is made of a synthetic rubber sheet material known as ethylene propylene diene monomer (EPDM). These easy to recognize roofs are either ballasted or weighted down with large river stone or glued down during their installation.
- Modified Bitumen: Developed in the early 1960s, modified bitumen roofing is a lightweight alternative to built-up roofing. It’s a DIY-friendly system as it can be installed without making a mess. Its single layer of adhesive roofing material is generally installed using a torch to optimally heat the rear side of the material to melt it to the base layer.
Pros of Flat Roofs
- They’re Affordable
The materials used in flat roofing are inexpensive, thus making them affordable. Labour costs are also lower because installation is less complicated.
- They’re Easy to Install
As mentioned, it’s easy to install a flat roof and takes less time than the alternatives. And repairs are painless because it can be fixed quickly.
- They’re Versatile
Unlike sloped roofs, flat roofs are accessible and thus easy to inspect for damage and leaks. You can also utilize the rooftop in many ways such as creating a deck, garden, or using the for relaxation or entertainment, such as parties or other get-togethers. Flat roofs are the best locations for solar panels as well.
- They Allow Space for HVAC Units
Flat roofs offer enough space to hold HVAC units, including commercial ones. It’s safer to install your building’s HVAC on its roof to avoid vandalism or damage.
- They’re Energy Efficient
Flat roofs are more energy-efficient than sloped ones because they have a membrane system applied on top of rigid sheets of insulation. The absence of gaps blocks the passage of air.
- They’re Easy to Clean
As flat roofs are more accessible than other roofing systems, they’re easier to maintain. Being able to access every part to clean it regularly prevents mould, algae, stains and debris from building up.
Cons of Flat Roofs
- They’re Less Attractive
Flat roofs are not about style, they’re about function. Typically they come in neutral colours like black, white and grey. So, if design and appearance are what you’re after, look elsewhere.
- They Have Drainage Issues
Flat roofs are prone to drainage issues because water tends to puddle. Unlike pitched roofs that have shingles to drain water, flat roofs need to be monitored for standing water, debris and clogged drainage. Consult your flat roofing contractor to install added mechanisms to address proper drainage.
- They Don’t Last As Long
Flat roofs generally need to be replaced after 10 to 15 years which may affect your ability to sell the property if the buyer is aware of its limited lifespan.
- They’re Less Stable
Buildings with flat roofs are less stable because their lack of proper drainage makes it difficult for them to withstand the weight of snow and pooling rain. This can lead to leaks along the seams.
Flat roofs are not the most stylish or stable option for either residential or commercial buildings, but they do have many benefits. Be a smart buyer and weigh their pros and cons when making your decision to get the best value for your money. An experienced and reliable roofing contractor is the best choice for building a durable and functional roof.