While flat roofs are not the most glamorous option, they have advantages. Knowing the pros and cons such as the price of flat roof repair, the roofing material required, potential ponding water and roof leaks help make a decision that is best suited for your building. Flat roofs construction consists of a top coat and underlayer.
Flat roofs are among the most controversial roofs of all the types of roofs for buildings and homes. They are most commonly used on outbuildings and large structures. Flat roofs have a unique set of challenges and needs. If you plan to have a flat roof on a residence or building, it is essential to know flat roof advantages and disadvantages.
Advantages
The biggest advantage of a flat roof is the expense. From building and installing to the materials commonly used for flat roofs, they are relatively cheap. The flat roof insulation board is approximately 80 cents per foot.
It makes a flat roof very affordable for both installation and upkeep and maintenance. Labor is cheaper due to less risk while installing a flat roof. Installation of flat roofs is quicker and easier. There are fewer damage and repair costs over the lifespan of the roof. Installing things like solar panels, which save on electricity, and satellites—making repairs and cleaning gutters less expensive and easier to accomplish on flat roofs.
The second advantage is space can be used for other purposes. Air conditioning units can be put on the roof instead of the ground. Flat roof solar racking installed on a flat roof is less evident from the ground than a sloped roof.
You can design a living roof that becomes an outdoor lounge area to relax or barbecue, or plant a garden on the rooftop. The list of possibilities for utilizing a flat roof is nearly endless.
A flat roof also makes interior space more versatile. Top floor apartments and finished attics are possibilities without the sloped walls produced by traditional pitched roofs. In homes that need maximum interior space, flat roofs are a significant advantage.
Flat roofs are typically more accessible than roofs that are sloped. They are easier to climb upon to inspect. Care and caution should be taken any time a person climbs on a roof. Flat roofs are easier to check and much safer. Flat roofs are substantially more stable than slanted roofs when the building is small.
They have an architectural appeal. In the right setting, they are economical as long as they are adequately maintained. Because flat roofs are quicker to install, the wait to move in is shorter. If repairs or replacement are needed down the road, re-roofing is relatively painless and quick.
Disadvantages
As the areas of a flat roof increases, the stability decreases. Industrial buildings and businesses that have flat roofs have to compensate for the weight on the interior. Flat roofs have limited options.
Material for flat roofs is a bit scarce. There are not many options from which to choose. Rolled roofing is used on the majority of flat roofs. The material is bitumen, TPO, Thermoplastic Polyolefin, EPOM or rubber. Each of these is relatively inexpensive and easy to install.
They have a limited lifespan. The life expectancy is between ten and 15 years. There are rubber shingles that can be installed along with rolled rubber roofing. Some new materials such as PVC and polycarbonate roofing are becoming available. They are more expensive. Because they are recently developed products, there is no information about how long they will last.
Draining, or rather lack of it is the biggest disadvantage. Flat roofs do not drain as efficiently as roofs with a pitch. Water tends to puddle and stay on the roof. The standing water can lead to the breakdown of roofing material or future leaks, especially along the seams. A flat roof contractor will likely install added mechanisms to address proper drainage. Water removal options are time-consuming and can be expensive.
Proper sealing of both the top coat and underlayer is critical to the roof’s integrity. The coating is subject to regular flat roof leak testing to ensure there are no leaks. Flat roofs are typically installed in warm climates.
Buildings with flat roofs are more affected by extreme changes in temperature because there is less space for installation. Most cannot withstand the weight of built-up snow in the winter.
There are flat roof companies that feel that insulation and snow weight problems are misconceptions. They suggest flat roofs can be installed in cold climates when the roofs have a substantial thickness that leaves room for sufficient insulation. A thick roof can also support snow accumulation as long as it is not due to an avalanche. The snow adds to the insulation.
TPO Roofing Systems
TPO is an excellent roofing system for warm climates. TPO roofing systems are an example of the improvements to flat roofs that are being explored. The seams of TPO roofs are welded instead of glued. They are less likely to separate when heated.
Manufacturers certify flat roof contractors to install the membrane and honor the warranty. TPOs gave a white surface that reflects ultraviolet light and keeps the structure cooler than other options.
Because the system is relatively new, revisions and improvements are ongoing. The maintenance requires flat roof repair contractors addressing shrinkage caused by prolonged exposure to UV rays.
They cause stress on flashing and seams. The warranty on TPO roof systems is only 15 to 20 years. The welds of both hand-held and walk-behind welding must be checked. Welding that does not take, must be patched.
Long and short seams require different welders. The lack of uniformity causes seams to fail and leaks on the roof. Commercial skylights for flat roofs cannot be welded with walk-behind welders used for long seams.
Short seams are needed for A/C units, drains, vents, and skylights. These areas are welded with a hand-held heat gun. The heat difference between the long and short seams becomes an issue.
Heat-welded seams must be correctly calibrated throughout the day of flat roof installation. The quality of a welded seam is affected by wind, cold, and humid weather conditions. A tool is used to check the seam quality to ensure the welds take.