Will a Flat Roof Work in the Pacific Northwest?

When choosing the best roofing option for your Pacific Northwest home, one front runner is a flat roof. It is increasing in popularity by the day primarily because of its unique look and modern aesthetics. True to its name, flat roofs are laid horizontally on top of your home (with a slight slope). Asphalt and torch are the most common materials for a flat roof project.

Whether you're looking to replace your old roof or install one from scratch, let's discuss whether (or not) a flat roof will work in the PNW areas: Oregon, Washington, Idaho, Montana, Wyoming, and Alaska.

Flat Roofs in the Pacific Northwest: Is It a Good Idea?

Generally, flat roofs are not considered the most suitable for homes in the Pacific Northwest, considering the immense rainfall in the area every year. But this doesn't mean a flat roof is a bad idea. You can expect it to last for decades if you're going with the correct design, proper installation, and construction for your flat roof.

Contrary to popular belief, flat roofs aren't 100% flat. The design has a slight pitch to ensure proper water drainage. If you choose to work with a roofer experienced in installing flat roofs, you can expect that your new roof will drain water well (without the pooling). (Related: A Great Roof Following the Best Standards in Tigard)

Advantages of a Flat Roof in the Pacific Northwest

Flat roofs in Pacific Northwest buildings provide an increased surface area, giving you more storage space and installing various HVAC units. Its aesthetic is also enough to give your home a modern look.

Aside from storage, the increased space can be turned into an outdoor living space extension (garden or patio). Installing a flat roof is also considerably cheaper than standard pitch roofs, as you won't need many building materials.

Disadvantages of a Flat Roof in the Pacific Northwest

Since flat roofs have a low pitch, expect to deal with several water leakage-related problems. One way to get the most out of flat roofs is to opt for seamless material, including PVC, TPO, and rubber membranes.

A flat roof installation project costs less when compared to other roof types– but this doesn't mean you'll save a significant amount of money. In the long run, you may need to spend more on their upkeep, especially in high rainfall areas such as the PNW.

4 Important Flat Roofing Considerations to Keep in Mind

Before giving your flat roof installation project the green light, here are some of the most important considerations to remember.

  • Maintenance ─ You must devote sufficient time (and money) to your flat roof maintenance activities. Unlike traditional pitched roofs, water may collect on your flat roof over time. The last thing you'd want is to let standing water and other debris accumulate on the roof surface, as this may only result in more costly repairs and possibly extensive damage.
  • Cost ─ Installing a flat roof will cost you more than what you'd typically pay for a standard roof installation, as they require more components such as a cover board, proper insulation, and vapor retarders. This makes the roofing Class A fire-rated. Since roofers can easily access a flat roof, this project can be completed fast. They also won't need engineered trusses usually required in pitched roofing projects.
  • More Space ─ Flat roofs provide the additional space you need in your home, which can be great news if your house has drastic or extreme angles. For instance, you can opt to add an entertaining outdoor space such as a rooftop deck or patio.
  • Average Lifespan ─ Flat roofs made of asphalt notably has a shorter lifespan because of their frequent direct water exposure in the PNW area. But, you can count on your new flat roof to last for up to 15 years of good use.

Finding a Reputable Roofer for your Flat Roof Project in PNW

You can never go wrong with going straight to the experts to decide whether or not a flat roof fits your home well. Here are other tips to keep in mind when choosing a local roofing company to handle the project.

  • License ─ Always ensure that your roofer has the proper license (up to date) before permitting them to start with the project.
  • Worker’s Compensation Insurance ─ Roofing companies are required by law to have workman's compensation insurance, but it won't hurt to double-check. This protects any worker who may get injured on your property, saving you from footing the medical expenses.
  • Past Customer Reviews ─ You can always check their past customer reviews if you want to get an idea of how a local company installs flat roofs. This will also help you manage and set your expectations. Consider testimonials indicating unprofessionalism and poor workmanship as red flags.

Frequently Asked Questions

What are the most common issues with flat roofs?

If water can penetrate through the roof barrier or membrane covering, this may lead to leak-related problems. It may also damage the insulation and structure underneath it. Be wary, though. The damage can be easily overlooked as it can go unnoticed over time. That's why we recommend consulting a professional roofer to ensure your flat roof installation project is well toward its maximum life expectancy.

What is the best way to maintain a flat roof?

The best flat roof maintenance activities take some time and effort on your end. Ideally, it would be best if you did everything you could to ensure an even roof surface to avoid pooling. If your roof needs better pitch, use roof leveling products such as RoofSlope to fill the lower spots. This allows you to improve the roof's current drainage level and avoid the possibility of leakages. Also, always ask questions about your new flat roof with your roofer. Consult about the annual maintenance requirements to avoid pressing issues such as roof leaks.

Why is there such a drainage problem?

Since there is little to almost no pitch, drainage problems are common in flat roofs. Flat roofs with excellent drainage are primarily because of their large pitch, allowing water to run down the gutters or on the ground. If your new flat roof deals with poor or inadequate drainage problems, expect to deal with persistent leak-related issues eventually. Since the water will only pool on the surface without anywhere to go, it may only drip down from any hole. In the event of heavy rains, you will most likely deal with the headache of leaks until you decide to do something about it.

Why are there low spots on a flat roof?

Another common issue in new flat roofs is having low spots, which can be attributed to the little drainage in the area. Rainwater will only pool into various areas of your roofing. When overlooked, the weight of these puddles will lead to low spots after quite some time. This issue may result in leaks and other problems that require costly extensive repairs. As previously mentioned, opt to fill in the visible low spots on your flat roof as soon as possible. Doing so evens out the roof and prevents the existence of roof holes, the culprit behind puddles and pools.

Why do flat roofs crack?

Unfortunately, flat roofs are notoriously prone to cracks. Though it is constructed with an asphalt layer, it is still directly exposed to the sun daily. During scorching temperatures, the asphalt may crack. Also, the harmful UV rays may wear down the asphalt and other roofing materials on your flat roof. It may cause the roof to split in the long run, requiring new roof coating to avoid further unforeseen maintenance issues.