Flat roofs are versatile, durable, affordable, and environmentally friendly, making them an excellent choice for homeowners. But like all roofs, flat roofs require maintenance, or serious problems will arise. Thankfully, flat roof maintenance is pretty straightforward. Let’s discover common flat roof issues and how to maintain a flat roof.
What is a Flat Roof?
A flat roof, or a low-slope roof, is a roof that is nearly level. A flat roof is visually different from many other roofs, which are sloped, and the degree of the slope is known as a roof’s pitch. A flat roof’s pitch is 10 degrees or less, though a flat roof is never truly flat. While there are many types of flat roofs, they’re all ideal for extra living space, rooftop gardens, or green roofs.
How to Maintain a Flat Roof
Like all types of roofs, a flat roof system needs regular maintenance. Here are some crucial roof maintenance tips to keep your flat roof in tip-top shape.
Clean Off Debris
Due to the flat roof’s design, it’s easy for debris to accumulate on your roof. To avoid problems like clogged drains, blockages, and pooling water, regularly remove debris from your roof. If you don’t want to or are unable to clean your roof regularly, the average professional roof-cleaning costs $490.
Check Drainage
While flat roofs have many benefits, one downside is that they don’t drain as easily as pitched roofs. To ensure that rainwater is properly removed from your roof, check your drainage system regularly. The checking frequency depends on the type of flat roof drainage system installed on your roof.
There are four main types of flat roof drainage systems.
- Inner drains: Drain pipes are located inside the roof, protected from the elements, so the system lasts about 50-60 years. However, the sink-like drain can be susceptible to blockages. Installing strainers helps prevent clogs.
- Scuppers: Scuppers are openings in the roof’s perimeter. They’re easy to maintain and rarely clog, but they don’t carry water away from the walls and foundation, which can lead to water damage. Scuppers are also less effective in downpours.
- Gutters: Gutters are the most common roof drainage system for residential homes. A half tube that runs the perimeter of roof catches rainwater and sends it to a downspout and away from the foundation. They’re cost effective and excellent in a downpour, but they’re vulnerable to severe weather like hail, and you’ll need to watch for signs of clogs.
- Siphonic Roof Drains: Siphonic roof drains use a siphoning system to remove water from your roof. A few outlets around the rooftop suck the water from the roof and into a single downspout which delivers the water away from the foundation. Siphonic roof drains rarely clog and work well in heavy rain, but they can be noisy.
Inspect for Problems
Whether you hire a roofing contractor to do your roof inspections or do it yourself, your roof needs to be checked regularly for issues that arise. Tears, punctures, and improper drainage need to be fixed as soon as you notice them. Small tears eventually cause leaks, leading to water damage or even a collapsed roof.
There are several common problems with flat roofs, including:
- Ponding water
- Biological growth
- Debris buildup
Keep Weight to a Minimum
A huge benefit of having a flat roof is that you can create an additional outdoor living space. However, adding too much weight causes stress, depression, and ponding. Just add a few essential items, like light weight outdoor seating or plants, and you’ll be able to enjoy your flat roof without the risk of damaging it with heavily weighted extras.
Also, because ice and snow won’t naturally slide off like they would on a pitched roof, it’s important to remove winter weather buildup from your flat roof. If you don’t, the extra weight will cause stress, depressions, leaks, and cave-ins. You can remove the snow using a shovel as long as you’re careful not to damage the roofing material, or you can hire a professional.
Trim Trees
Trees add beauty, shade, and fresh air to your outdoor space, but they can cause big problems for your roof. Leaves, pine needles, and other tree debris cover your roof, creating clogs, water ponding, and biological growth. Limbs and branches crash into your roof, tearing and puncturing it. Keeping your trees healthy and trimmed will help prevent tree damage to your roof.
Protect It From the Elements
There are steps you can take that will prevent or mitigate flat roof damage from the sun and weather.
- Flashing: Typically made of galvanized steel, flashing is installed at a roof’s weak areas, like the chimney, vents, or skylights, to protect against water damage. Instead of sitting in these areas, the water runs over the flashing and onto the shingles.
Flashing reduces the need for repairs in weak areas, but you’ll need to check for peeling, buildup, and loose flashing when doing your normal roof maintenance.
- Waterproofing: Adding a flat roof coating to your roof creates a waterproof barrier, protecting your roof against ponding and rain.
- UV-Protection: The sun gives your roof a beating, but if you add a cool-roof coating, gravel, or polyurethane foam, you can protect your roof against UV rays.
Common Issues With Flat Roofs
All roofs have issues that arise because they’re outside, exposed to the elements, and vulnerable to falling objects, but flat roofs have unique issues. Watch for signs of damage so you can take steps to prevent more issues. Here are the most common problems with flat roofs.
- Biological growth: Vegetation grows anywhere under the right conditions. When debris isn’t cleared and water doesn’t drain, algae, moss, and plants are free to grow and thrive.
- Blistering: When the top layer of the roof loses its adhesion, air or water pockets form, looking like bubbles. If left untreated, these pockets will grow and damage the roof.
- Alligatoring: Alligatoring happens when the roof’s membrane deteriorates and cracks. When this happens, the roof begins to look like alligator skin.
- Debris: Because flat roofs don’t drain as freely as sloped roofs, built-up debris causes drainage clogs, which leads to irreparable damage. Regularly removing leaves, dirt, sticks, and trash will prevent problems from arising, like ponding water and drainage clogs.
- Exposure to the elements: Exposure is a problem for all roofs, but because flat roofs have such a low pitch, they’re more vulnerable to the effects of the sun and weather conditions.
- Leaks: Like all roofs, leaks can become a major problem for flat roofs. But because a flat roof’s pitch is so low, it’s harder for them to shed water. So when cracks, water pooling, or other sealant problems form, water will leak through the roof, creating water damage, mold, and potential health hazards. The average roof leak repair costs $1,195.
- Ponding water: Although flat roofs have a slight pitch for draining, various obstacles can prevent proper water drainage. The result is puddles of standing water called ponding water. The ponding water causes sagging, rot, and, eventually, roof collapse. The reason for ponding water varies from clogged drains to structural problems.
- Shrinkage: When a flat roof is made from synthetic rubber membranes, they eventually experience shrinkage. Shrinkage is caused when the rubber roof seams pull apart. Eventually, openings form on the roof’s surface.
- Structural movement: Due to changes in weather and temperature, the materials of a building naturally expand and contract. This process is called structural movement or thermal movement. While the structural movement is natural, it causes flat roof membranes to crack and split, especially near seams and flashing.
- Tears, splits, and punctures: Because a flat roof is nearly flat, it’s more prone to a direct hit from hail and falling debris. Both can cause tears, splits, and punctures in your roof, which, if left untreated, will worsen with time. It’s important to note that foot traffic on a flat roof also can cause tears, splits, and punctures.
- Neglecting maintenance: When you don’t perform routine maintenance, minor problems – like debris build-up or clogged drains – become big problems – like rot and roof leaks. Clear debris, check for cracks, and make small repairs twice a year to ensure a healthy roof. It’s important to note: insurance won’t cover neglect damage.
How Often Should You Maintain a Flat Roof?
Your roof should be cleared of debris and checked for damage at least twice a year, once in the spring and again in the fall. However, in a few circumstances, you should maintain your roof more often.
- Trees surround your home
- Severe storms
- Heavy rain
- Strong winds
- If you notice leaks
- A neighbor is experiencing roof problems
FAQ About Maintaining a Flat Roof
The average lifespan of a flat roof is 10-20 years. However, several factors affect the longevity of your roof, including:
• The roofing materials used to build your flat roof (Bitumen, EPDM, TPO, PVC, etc.)
• The weather in your area
• The temperature in your area
• The nearby vegetation, especially trees
• The roofing company’s craftsmanship quality
To ensure the integrity of your flat roof, reseal every five years. If your area is particularly prone to severe temperatures or weather, you should reseal more often, but if you live in a mild climate with few storms, you can reseal less frequently.
It depends on the cause of the damage. If your flat roof was damaged in a storm or fallen limbs, your homeowner’s insurance should cover the cost under peril coverage. However, you will need to meet your deductible first. Keep in mind that if your roof is damaged due to neglect or lack of proper maintenance, your insurance won’t help.
Whether your insurance contributes or you foot the bill entirely, the average cost of flat roof repair is $725. While flat roof repair is a little pricy, the cost rises as problems get worse. In fact, the average cost of a flat roof replacement is $9,000. It’s also a good idea to check your roof’s warranty to see if the manufacturer can cover any damages.
Hire a Professional to Maintain Your Flat Roof
Depending on what needs to be done, you can DIY your roof’s maintenance. Cleaning debris, checking for problems, or fixing small tears are simple DIY projects. On the other hand, DIY maintenance takes time, and time is precious. It’s also a little dangerous. Falls are the second most common cause of accidental home deaths.
If you’d rather enjoy your time with the people you love and the things you love doing instead of balancing precariously on your roof, Roof Gnome can help. We’ll connect you with a local, highly-rated professional roofer. Your flat roof will be sparkling clean and free of needed fixes in no time.
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