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5 Signs It’s Time for Flat Roof Replacement

A flat roof is exactly what it sounds like: a roof that has very little slope to it. Usually, this style of roofing is used primarily in commercial applications, especially in the Pacific Northwest. You’ll find more residential flat roofs in parts of the country that are arid because one of the drawbacks to having a flat roof is that it can be difficult to find and repair leaks. With our consistent precipitation, no one wants to deal with that in their home.

The benefit of having a flat roof is that you can also use it for additional space. For instance, green roofs or eco-roofs are popular places to have small gardens where a roof is visible to inhabitants of the building or those around it. In urban places, such as downtown Portland, apartment buildings, colleges, and medical complexes are creating green spaces on the roofs visible to their students, patients, and occupants. This way, architects are also creating spaces for stormwater management, reducing the urban heat island effect—where cities have a higher ambient temperature due to so much concrete—and also creating spaces for pollinators such as bees and hummingbirds to live.

So, if you have a flat roof, how do you know when it’s time to perform some maintenance or replace it? Here are five signs it’s time for flat roof replacement:

1. Cracks in the Flashing

Anywhere there is a sharp bend on your roof—any 90-degree angle—there will be flashing, which seals water away from the interior of your building. Think of flashing as the seams of your roof. If your flashing is cracked and old, water has a natural pathway into your building. Needless to say, it can cause a lot of damage to the wooden joists under your roof, the support beams, and any insulation that might be there. You can bet that if you can find old and worn-out-looking flashing, other parts that you can’t see will need to be replaced too.

2. Blisters Forming

You’ll see this more commonly in a flat roof that has membrane roofing. Blisters or bubbles form when pockets of air or moisture are trapped between the layers of the membranes and can be exacerbated by regular foot traffic. Sometimes, they are a result of a crack in the seam, which then collects moisture or cold air from below.

If you catch a blister before it cracks, you can sometimes repair the roof instead of replacing it. However, if it’s a consistent problem, or the blisters or bubbles show up all at once all across the roof, it’s probably time to consider replacing it. Even if you’re able to repair one blister, there’s a good chance it will come back again and again.

3. Water Is Pooling

This is actually the biggest and most common problem with flat roofs, especially here in the Pacific Northwest. Since we live in a wet climate, you want to be sure that there are no places on your roof where water will “pond” or pool and have appropriate drainage. If you have a space where there is a consistent pool (and if your roof is fairly new), you can install additional roof drains or a tapered system. Of course, if you are maintaining an old roof rather than fixing a new one, you may have bigger problems. The faster you get the water off the roof, the better the chance you won’t spring a leak.

4. Building Materials That Hide Damage

You may think this is a good thing at first, but if the damage is hidden, it may not occur to you to repair or replace the roof until it’s too late. If you have a tar and gravel roof—which is becoming less and less popular for this reason—it may be difficult to actually find the damage, and even an experienced contractor may only have a 50-50 chance of finding the leak. If it’s time to replace the roof anyway, make sure the flat roof replacement material is something that is easy to work with and shows damage instead of hiding it.

There are many types of flat roof coverings, including asphalt, synthetic rubbers, liquid membranes, and glass-reinforced plastic. They all have advantages and disadvantages, so make sure you ask your highly experienced technicians at Interstate Roofing which one is right for your building and your budget.

5. Alligatoring

Have you ever seen the pattern in an alligator’s skin? You’ll see similar patterns in the cracks that can form in your roofing material. As the sun’s UV rays dry out the top layer of your roof, you’ll be able to see this kind of damage. Remember, while it’s frequently cloudy in our climate, some UV rays will still get through and slowly degrade your roofing material. Clouds only block some rays—not all of them. If you don’t handle this problem, these cracks can let in ice and water, and the heating and cooling cycles will make these cracks wider and lead to more and more problems.

But if you replace your roof, or if you apply a new coat to the roof when you first notice these patterns, you can say, “See you later, alligator!” to this particular problem. If you have noticed alligatoring in the past, or if you’ve recently replaced your flat roof, it’s good practice to inspect your roof every six months or so and after major storms, including ice and wind storms.

Flat roofing is one of our specialties at Interstate Roofing. We’ve worked on many large commercial buildings in Oregon and Washington, such as churches, office buildings, medical complexes, restaurants, warehouses, and multi-family structures. We were also awarded the Versico Gold Medal Quality Award for our work on the Timberline Wy-East Day Lodge. Having been in this business for over 30 years, it’s no wonder Interstate Roofing is the obvious choice for your roofing needs, whether it’s commercial or residential.

What Is TPO Roofing for Commercial Roofs?

At first glance, the roof of a commercial building may seem like a very simple thing. After all, unlike residential roofing, commercial roofing is usually flat, and as opposed to being made of many parts like shingles, it’s made from one layer of some other material. And while it’s true that the basic design may not be complex, there’s a lot of science that goes into the rooftops of commercial buildings.

There are several reasons for this, but primarily, it boils down to two things:

  1. Protection from the elements
  2. Energy efficiency

One common material that can check both boxes is thermoplastic polyolefin, or TPO. In the city of Portland, TPO roofing can be found adorning the tops of thousands of buildings. Read on to find out why it’s so popular.

What Is TPO Roofing?

TPO is a single-ply synthetic material that’s sold commercially in large rolls. While the term “single-ply” usually means it’s made of a single layer of material, it’s actually made from three layers. The first is a synthetic polymer base, essentially a type of plastic. Layered on top of that is an extremely strong reinforced fabric center, strengthened with another synthetic material: polyester. Finally, the top, protective layer serves to hold the whole thing together. It’s this top layer that’s made from the thermoplastic polyolefin that gives this particular roofing material its name.

The word “thermoplastic” implies that the material has something to do with heat, and indeed, that’s the most important feature of TPO roofing. This material can be easily heat-welded to itself, allowing individual sheets to be joined to one another across the whole of a roof with ease. This means that, even with a very large roof, the material can be joined together seamlessly.

What Are Its Benefits?

As we’ve mentioned, the ability of TPO to be heat-welded means that it can be turned into one huge layer across a rooftop of any size. Because of this, it serves as an excellent layer of protection against the elements, with no weak spots where leaks can develop. Even if they do develop, the material can be repaired fairly easily through the same heat-welding properties.

TPO also has a great beneficial effect on the energy efficiency of a building. If you own a commercial building, you know that saving money on energy costs is a must, and TPO can do this effectively by reflecting away a great deal of sunlight that strikes the top of the building. This is the result of both its advanced design and its stark white color, which reflects solar radiation and keeps the cost of air conditioning down, saving money for businesses that opt to use this unique type of material.

Its ability to resist solar radiation makes TPO both energy efficient as well as environmentally friendly. Actually, it’s made entirely of recyclable materials. This means that once this durable roofing material has finally reached the end of its useful life, it can simply be recycled back into new TPO roofing.

Finally, TPO roofing isn’t just resistant to sunlight. It’s created to resist rain, mold, fungus, oil, heat, cold, and even earthquakes. The material’s flexibility means it’s unlikely to give way even if the building itself moves a great deal.

Is TPO Roofing Right for My Building?

TPO, of course, isn’t the only synthetic material that can be used to layer on top of commercial roofs. In Portland, TPO roofing is popular due to the relatively warm summers. Many business owners expect that it will save them a good deal of money over the years. Other climates, however, may benefit more from roofing materials that are designed for cold weather. This includes roofing materials such as EPDM, which is black in order to absorb heat rather than reflect it away.

Business owners should also consider what types of materials are best for their specific building. For example, because TPO is designed to resist a large number of chemicals and other harsh materials, it can be perfect for the roofs of factories and restaurants, which may vent materials that are otherwise damaging to rooftops.

Ultimately, when choosing a roofing material, you’ll have to weigh your needs with regard to energy, durability, and the climate where you are located. Weather has a major effect on the best type of materials for constructing buildings. That’s why it’s a good idea to research the average weather for a given year in your area before making any commitment to specific roofing materials.

Is It Expensive to Install?

TPO roofing is usually fairly inexpensive to install. The cost is usually around the same as other, similar roofing materials. However, business owners should be wary of having their roofing work performed by the lowest bidder. While it’s true that the job shouldn’t be expensive, if a deal seems too good to be true, it most likely is.

A good roofing contractor will be highly trained and certified to do the type of work that they do, as well as properly insured. If they aren’t, then the possibility exists that they may do more harm than good to a commercial rooftop, ultimately costing business owners more money than they save.

For these reasons, it’s a good idea to do some comparison shopping when seeking a contractor to do roofing work on a commercial building. Check references, read reviews, and compare prices to get a good idea of what you can expect to pay for this type of job.

In the Portland area, a company like Interstate Roofing is your best bet. Experienced roofers also offer emergency services, should any problems arise—even at inconvenient times. Contact us with any questions have about your commercial roof.