In Arizona, flat roof recoating is a hot topic. Flat roofs are a familiar sight on both homes and businesses, especially in older neighborhoods and on custom and semi-custom homes on the outskirts of Maricopa County. The popularity of flat roofing stems from its practicality and cost-effectiveness due to Arizona’s dry and sunny climate. However, if not installed and maintained correctly, flat roofs can develop problems with leaking that can be very expensive to fix. Today we’ll explain how often you should recoat your flat roof, so ensure you extend its lifespan as much as possible.
The Short Answer:
For an SPF flat roof, GM Contracting recommends flat roof recoating every 5-7 years in Arizona, due to the hot, dry climate. If you live in a milder climate, it’s possible that your flat roof could go for up to 10 years maximum without needing a recoating. However, to be safe, we recommend playing it safe, and at least inspecting the flat roof yearly, to ensure that it doesn’t develop problems that could be very expensive to repair.
How Flat Roofs Are Constructed
When addressing the issue of flat roof recoating, it’s important to consider how flat roofing is actually constructed. This will give you a better insight into why flat roof recoating is suggested every 5-7 years.
Decking: The base layer, usually made of plywood or oriented strand board (OSB), provides a stable foundation for the roof.
Insulation: Materials like foam boards or rigid insulation are placed on top of the decking to provide thermal resistance, regulating the building’s temperature.
Membrane: This waterproofing layer is made of materials such as modified bitumen, EPDM (ethylene propylene diene terpolymer), PVC (polyvinyl chloride), TPO (thermoplastic olefin), or built-up roofing (BUR) materials, preventing water penetration.
Flashing: Metal flashing is applied around chimneys, vents, skylights, and other protruding structures to seal joints and edges, preventing water infiltration.
Drainage System: Flat roofs require an efficient drainage system, including drains, scuppers, gutters, and downspouts, guiding rainwater away from the roof and the building’s foundation.
These components work together to create a structurally sound and weatherproof flat roof. It’s also important to note that flat roofs are not actually flat. They are designed with 1-10 degrees of slope to ensure that water drains effectively. If a flat roof doesn’t have any slope, or the slopes aren’t designed well upon installation, water will “pond” and extensive damage becomes much more likely.
What Are The Visible Signs that a flat roof Should be recoated?
If you see air pockets, exposed material, or signs of water pooling on your roof, those are all common signs you may want to get your flat roof recoating project completed sooner, rather than later. Leaving these issues unattended can allow rainwater to rot your underlayment. The last thing you want is to have extensive damages and potentially have to replace your whole roof. Remember that inspections should happen every year, after the monsoon season, to ensure your flat roof is in good shape for next season.
How your Flat roof's original construction affects recoating
The truth of the matter is that damage is not inevitable and can be prevented if your roof was installed with a well designed path for water to escape. If you want to make sure your roof was installed well and sheds water, we recommend cleaning your roof of debris, then after it rains, look to see if water is ponding anywhere on the roof. If water remains for more than 48 hours, you likely have a drainage problem that needs to be addressed.
How to make your Flat roof Coating last longer
If you see air pockets, exposed material, or signs of water pooling on your roof, those are all common signs you may want to get your roof recoated soon. Leaving these issues unattended can allow rainwater damage and rot your underlayment. The last thing you want is to have extensive damages and potentially have to replace your whole roof.
Many of these damages can be prevented by making sure your roof is draining properly. The #1 problem that causes flat roofs to fail early is poor drainage. Usually this is caused by a poor installation, or when debris builds up and block water from escaping.
Regular cleaning
Issues arise when it rains and your roof is covered in debris that prevents the water from escaping. Trapped water can cause parts of your roof to rot or deform, so it’s very important to make sure your roof is shedding water easily at all times, especially during the rainy seasons.
We recommend that, if it’s safe to do so, you go up on your roof and clear it of debris once a year, around May, before the summer monsoon storm. Make sure to clear your scuppers (the drains that let water out the sides of your roof). If your house is surrounded by trees that shed their leaves in the fall or winter, we also recommend that you clear your roof of leaves before the winter rains begin.
If you do not feel safe climbing on your roof, please contact professionals! It’s better to be safe!
different types of recoating materials For Flat Roofing
Polyurethane, silicon, and acrylic coatings are the most popular choices for flat roofs, each offering distinct advantages and disadvantages.
Polyurethane coatings are highly durable and provide excellent protection against harsh weather conditions, making them a preferred option for areas prone to extreme weather fluctuations. They offer superior resistance to UV rays, ensuring long-lasting performance. However, their application can be tricky and typically requires professional installation.
Silicon coatings, on the other hand, boast exceptional UV resistance and are highly flexible, accommodating a roof’s natural movements without cracking or peeling. They are also excellent at resisting ponding water, a common issue for flat roofs. Despite their durability, silicon coatings tend to be more expensive than other options.
Acrylic coatings are cost-effective and easy to apply, making them a popular choice for budget-conscious consumers. They reflect sunlight effectively, reducing cooling costs, and are available in various colors. However, they are not as resistant to ponding water as silicon coatings and might require more frequent reapplications. Choosing the right coating depends on specific requirements, budget constraints, and the climate of the region in which the flat roof is located.
For the Arizona climate, we personally recommend polyurethane mixed with granules. The added granules prevent birds from nesting or “doing their business” on your roof. If you’re contemplating a flat roof recoating, we recommend this coating as the best balance between cost and benefits.
When It's Time to Contact a Professional For A Flat Roof Recoating
As a homeowner, it’s essential to recognize when it’s time to seek professional help. The importance of professional assessment, finding a qualified roofing contractor, and scheduling regular roof inspections and coatings cannot be overstated. These steps ensure that any problems with your roof’s coating are handled well and don’t lead to more expensive issues in the future.
If you need help cleaning, inspecting or recoating your roof let us know! We are flat roofing specialists and we’re passionate about helping homeowners’ take care of their homes.
