Roof Types

Roof Types archives for the Interstate Roofing Blog, we serve the Portland & Vancouver metro areas with residential, commercial, repair call 503 684-5611

What Materials Make the Best Shingles for the Pacific Northwest?

The Pacific Northwest is famous for its cool and temperate climate, with clouds, wind, and rain regularly doing a number on every rooftop in the area. During the winter, ice and snow can give these same rooftops a further beating, not to mention wear and tear from leaves, falling branches, and other debris carried by all of this inclement weather.

Of course, even a pleasant sunny day without a cloud in the sky can take its toll: the sun’s ultraviolet radiation beats down on rooftops and causes them to deteriorate over time.

Because weather is so hard on rooftops, particularly in the Pacific Northwest, you need to make sure you have the right materials making up the shingles of your rooftop. In this article, we’ll look at why composition shingles are the best shingles for Pacific Northwest homes.

The Parts of Your Roof

A roof is made up of several different elements. It begins with a wooden frame called fascia, with a wooden decking built on top of that. These parts give the roof structure. The rest of the materials used to make up the roof are used to protect the home from the elements.

Attached to the wooden decking is a thick layer of felt called the underlayment. Attached to the underlayment are the flashing, which helps direct water off the roof, and the shingles.

What Are Roofing Shingles?

The shingles on your roof are its first line of defense against the elements. They protect from sunlight, rainwater, and other debris. Shingles are flat, rectangular pieces that fit over each other in an overlapping pattern. They are attached starting at the base of the roof and toward the top of it.

Shingles can be made from many different materials. Stone such as slate is also popular as is wood. As you may imagine, these materials can be expensive which is why most homeowners opt for less expensive options.

Finding the Right Roofing Materials for Your Home

Fortunately, there are options for shingles that marry cost savings with the added aesthetic appeal of slate shingles. Composition shingles, which are also known as asphalt shingles, are one of the most popular choices available. They are usually made from a fiberglass mat that is covered with a layer of tar and a mixture of granules to ensure a lightweight, inexpensive, waterproof protective layer for the roof of your home. Certain composite shingles are created to have the appearance of slate shingles while still costing a fraction of the price of the more expensive material.

If your building happens to have a flat roof, rather than a sloped one, the best material is probably an artificial membrane called TPO, which stands for thermoplastic olefin. This material is made of a polymer base created from the aforementioned thermoplastic. On top of that is a reinforced fabric center, and on top of that, a top ply made from thermoplastic polyolefin. This roofing material works well for flat roofs because it’s highly UV resistant: flat roofs deal with the sun’s rays even more than sloped ones do. They are also likely to have less effective water drainage. TPO materials help prevent leaks.

What Happens When the Shingles Are Lost or Damaged?

Shingles are durable, but inclement weather can still damage them. Heavy winds will pull shingles off of the roof and blow them away; ultraviolet solar radiation will wear them out; and ice will form underneath them, eventually leading to leaks.

If the shingles on a rooftop are lost or damaged, air and water will eventually leak through the holes in the roof. If air gets in, it can dramatically drive up energy costs in a home by reducing the efficiency of the heating and cooling systems. If water gets through one of the holes in the roof, it can encourage the growth of mold and dry rot. Water can also cause catastrophic property damage, possibly costing thousands of dollars to repair, and all because the roof was missing a few hundred dollars’ worth of shingles.

As you may expect, the problem of lost and damaged shingles is of particular concern in climates like the Pacific Northwest. The alternating wind, rain, and sunlight of this climate can put a lot of extra stress on rooftops, perhaps more so than in other climates in the United States. This is why the best shingles for Pacific Northwest homes are composite ones, or TPO for flat roofs. They are resistant to all of these weather conditions and are relatively inexpensive to replace.

Who Can Repair and Replace Lost and Damaged Shingles?

Properly cared for, roofing shingles, generally last about 20 years. However, they’re still susceptible to damage. Heavy winds and constantly falling leaves and branches are a risk to shingles, no matter how well-maintained they are. When you do lose a few, you don’t want to leave bare patches on your rooftop. Not only does it look unappealing, but it also puts the home at risk of further damage from the weather.

Because of this, it’s a good idea to have a great roofing contractor you can contact in case of a roofing emergency. It’s also a good idea to know who your contractor is before the emergency actually occurs. Do a little research into who is available in your area and how they have been reviewed by other customers.

Your best option is to look for a company like Interstate Roofing. We have years of experience in the industry. We’ll be able to address emergencies, as well as routine roof repairs and maintenance. If you’re interested in any aesthetic work or in roofing for a business, we’ll be able to do the job for you quickly and effectively, ensuring you get the most out of your roofing materials for years to come.


5 Facts About Eco-Friendly Rooftops

When you think of eco-friendly home products, eco-friendly rooftops may not be the first thing that comes to mind. You may have never seriously considered investing in one or know very little about them. If so, allow us to fill you in on a few things.

Interstate Roofing has been supplying rooftops to residents of the Pacific Northwest for more than three decades. We’ve seen how rooftops have evolved over time, including how they’ve evolved to become more environmentally friendly. Here are five facts about eco-friendly rooftops you should know.

1. Eco-Friendly Rooftops Can Save You Money

Did you know that going green could actually save you some green? While an eco-friendly rooftop may cost more up front, it’s an investment that could pay dividends down the line. Eco-friendly rooftops offer a great return on investment by increasing a home’s property value, for instance.

Not planning on selling your home anytime soon and wondering whether an eco-friendly rooftop could really benefit you? The short answer to that question is yes. Eco-friendly rooftops typically require less maintenance and have a longer life span than conventional rooftops. In fact, an eco-friendly roof that is well-maintained can have a life span that is more than double that of its conventional counterparts.

2. Eco-Friendly Rooftops Are Highly Durable

In addition to having a longer life span, eco-friendly rooftops tend to be more durable than traditional rooftops. If you live in a climate with extreme weather conditions and have a roof made of traditional materials, you could find yourself making constant repairs.

For example, have you ever seen the shingles fly off a roof in strong winds? Anytime a blizzard, hurricane, or strong thunderstorm passes through your area, you run the risk of having to make costly roofing repairs.

But eco-friendly rooftops are generally able to withstand extreme temperatures and weather conditions. If you live in an extreme climate, an eco-friendly rooftop may be the best option for you. Though the initial investment will cost more, you will likely find yourself spending less money on maintenance and repairs long-term.

3. Eco-Friendly Rooftops Can Improve HVAC Efficiency

Eco-friendly rooftops also help to improve HVAC efficiency, resulting in additional cost savings. Whereas traditional rooftops are typically made with heat-absorbing materials, eco-friendly rooftops are made with light-reflecting materials. So rather than absorbing heat and trapping it inside your home, eco-friendly rooftops reflect heat away, making your home feel cooler and much more comfortable.

This means your HVAC equipment won’t have to work as hard to cool your home during the warm summer months. If your HVAC equipment needs less energy to operate, your annual energy bill will be much lower. While eco-friendly rooftops are typically a long-term investment, you should start seeing increased energy savings from your eco-friendly rooftop relatively early on.

A cooler roof can also increase your comfort level in areas of your home that are not air-conditioned. For instance, if you’re trying to repair a car or complete a DIY project in the garage, you’ll feel much more comfortable doing so under an eco-friendly roof.

4. Eco-Friendly Rooftops Reduce Your Carbon Footprint

Eco-friendly rooftops will certainly benefit you and your family, but they’ll also benefit your neighbors and community. When a roof made of asphalt shingles reaches the end of its life span, it most likely winds up in a landfill. If you’re removing an asphalt roof, check to see if your roofing contractor can recycle the old shingles. Since asphalt is a petroleum product, replacing a roof can increase our reliance on fossil fuels. Most human-caused greenhouse gas emissions within the US come from the burning of fossil fuels, which can be harmful to our environment.

On the other hand, eco-friendly rooftops are often made from recyclable materials. When an eco-friendly rooftop reaches the end of its life span, it can typically be recycled again. This prevents waste from clogging up our landfills, reduces pollution, and improves air quality within our communities.

5. You Have Options

Some people mistakenly believe there is only one type of eco-friendly roof available, but you actually have several options when it comes to selecting eco-friendly roofing materials. Some, as we mentioned, are made from recycled waste materials. Others are made from metal and reflect heat, helping reduce your home energy costs. Slate roofs are another option and are among the most durable. In fact, some slate roofs have been known to last more than a century.

Other eco-friendly roofing options include clay tiles and “cool roofs.” Clay tiles provide aesthetic appeal because they evoke an earthy, rustic feel, but they have many practical purposes as well. Clay is a highly durable, 100 percent recyclable material that keeps your home well-insulated from both the heat and cold, reducing your overall energy costs.

There are many types of “Cool roofs.” As the name suggests, they help reflect the sun’s rays so that both your roof and home remain cool during the summer months. Some are made from white glue and white gravel and can reduce a roof’s temperature by as much as 50 degrees. Some are made of asphalt but contain special reflective granules. A downside of some cool roofs, though, is that they can be more susceptible to mold and algae growth. The Department of Energy has more information to help you determine whether a cool roof is a viable option for you.

Impact of Eco-Friendly Rooftops

Going green has many benefits, not only for the environment but also for your family and your wallet. When you choose to invest in an eco-friendly roof, you can save money by reducing your energy use while also protecting the environment and improving air quality within your community.

If you want to learn more about eco-friendly rooftops, give Interstate Roofing a call. There may be additional economic advantages, such as tax benefits, you could qualify for by installing one. We’ll make sure you have all the relevant information to help you decide if installing an eco-friendly roof is the right option for you.


What Roofing Materials Work Best for Oregon Roofing?

You want new roofing on your home. That’s a great idea! A new roof has many benefits for a home, from increased value to greater energy efficiency. But before you start calling contractors to get a quote, it’s a good idea to decide what kind of roofing materials might be best for your home. Oregon roofing companies can offer advice, of course, but it’s always good to be informed. So, what are the best materials for Oregon roofing projects?

Why Get a New Roof?

If you’re still on the line about reroofing your home, don’t be: there are many fantastic benefits to having a new roof. The benefits include:

  • Energy efficiency. Older roofs may have small holes that leak air, making it more expensive to keep your house heated in winter and cooled in summer. This means your HVAC system needs to use more energy for the desired result, which is not only bad for the environment, but also bad for your wallet.
  • Improved value. New roofs have a very high return on investment when it comes to improving the market property value of a home. Not only will your home look nicer, making it easier to sell, but listing a recently repaired roof will give any would-be buyers confidence that they’re making a good purchase.
  • Eliminating health hazards. An old roof could be harboring things like mildew or mold that, if left undetected and unchecked, can be health risks. Getting a new roof eliminates that problem.
  • Newer technology. If your home’s roof is from the 1980s, it’s using materials and manufacturing processes that are over 30 years old. Roofing technology hasn’t changed as much as, say, computers, but it’s always an improvement to have the latest and greatest techniques.
  • Peace of mind. If you’ve ever dealt with a leak, you know that even when it’s fixed, you dread it coming back. With a new roof, you know you have years before you need to worry about anything of the sort.

Whether you live around the country or in Oregon, roofing projects have a very high ROI.

But now we come to our original question: what are the best roofing materials for use in Oregon?

In general, there’s no one “best” roofing material. Instead, you should think of different options as suited for different climates and environments. Furthermore, another consideration is cost—do you really need the ultra-top-end materials when one that’s half as expensive might work 95 percent as well?

Different Roofing for Different Environments

The best type of roofing material ultimately depends on what the weather is like where you live. For instance, ceramic roofing tiles are excellent at dissipating heat and very resistant to salty air, which makes them great for houses in warm environments or homes built near the ocean. However, on their own, clay tiles are slightly water-permeable (though they typically are waterproofed), meaning they would be less suited for a very wet climate like Oregon’s.

Roofing in Oregon can be dramatically different depending on what part of the state you’re in. Most of the population of the state lives in the western part of Oregon, a temperate rainforest, and if you’ve lived in Oregon for even a short amount of time, you don’t need to be told that it’s very damp here. However, homes in eastern Oregon, with its dry climate, wouldn’t need similarly rain-resistant roofing.

One other weather consideration for homes in Oregon is fire risk. Unfortunately, climate change is making wildfires more dangerous, so while you want to obviously hope your home never is in the path of a fire, it must be something you should consider.

What Are the Best Oregon Roofing Materials?

Let’s look at some of the most common materials used for roofing here in Oregon (and around the country).

Asphalt Shingles

The most popular and most common roofing material in the USA, asphalt shingles are a safe bet to have on almost any home. Every roofing company will be familiar with how to install these shingles, and they strike a good balance between price, ease of use, and life span (about 15 to 25—don’t be fooled by the manufacturer’s “lifetime” label). An excellent default option for all environment types.

Wooden Roofing

Wooden shingles or shakes are beautiful, true, but they are difficult to maintain and few contractors still work with them, as the desire for cedar is minimal. A wood roof is vulnerable to fire and has a dramatically reduced life span in wet environments, both of which are present in Oregon. As gorgeous as a roof with wooden shingles can be, they’re not an optimal choice in this state, though they’re more feasible in the dryer eastern part of Oregon.

Metal Roofing

There are typically two main types of metal roofing materials suited for sloped roofs: standing-seam roofs, which have interlocking roofing panels made of steel or aluminum, and metal shingles, made from the same material but shaped like standard shingles. Metal roofing has a very long life span (upward of 50 years) and is highly resistant to heavy snowfall as well as fire.

The primary difference between standing-seam roofs and metal shingles is aesthetics. Some homeowners simply do not like the characteristic ridged appearance of standing-seam roofs. However, metal shingles are more expensive, and both types of metal roofs can be upward of three times as expensive as standard shingles. It might also be harder to find a company experienced with this installation.

Slate Roofing

The king of roofing materials, slate shingles can last decades if not centuries and make for truly beautiful roofs. However, it can be very difficult to find roofing installers who have experience working with slate. Moreover, saying something is the “king of roofing materials” also talks about its price: at a minimum, expect to pay 10 times for a slate roof what you’d pay for a normal asphalt roof, and the real price could be double or even triple that.

Do you want to know what material would be best for your new roof? Contact Interstate Roofing for a consultation.

What Are the Most Common Modern Roofing Styles?

As unassuming as it might seem, the roof of a building is one of its most important features. It helps to protect the inside of the building from the elements and keeps everything warm in the winter and cool in the summer. It contributes greatly to the value of a home, and although largely unsung, the roof is one of the most sophisticated pieces of building technology.

Of course, not all rooftops are created the same. There are many different modern roofing styles, each with a different purpose and specialization. Some are used primarily for homes, while others are more likely to be seen on commercial buildings. All of them are designed to serve their purpose—of keeping the inside of the building safe from the elements—and some can save you a great deal of money on heating and energy.

Below, we’ll list a few of the most common modern roofing styles:

Flat Roof

You’ll see this one on buildings everywhere, both commercial and residential. It’s very simple, being a roof that’s basically flat, and its primary benefit is in maximizing usable space inside a building. Since it won’t really be visible from the top, the flat roof doesn’t make use of decorative shingles, primarily utilizing asphalt, TPO, or PVC to reflect ultraviolet radiation away.

Despite the name, flat roofs are rarely truly flat. They still need to be able to allow for drainage of rainwater, so they almost always have a very slight gradient. Even so, flat roofs have a greater tendency to leak and let water in than other styles of rooftop, especially in areas that are prone to heavy rains, hail, and snow. If you do notice a leak, contact a professional from Interstate Roofing and ask them to come to repair it for you.

Gable Roof

Although this article is about the most common modern roofing styles, we’d be remiss if we didn’t mention one timeless classic: the gable roof. After all, a true classic never goes out of style, and indeed, the gable roof remains as popular on houses as ever. It’s the roof you imagine when you think of the classic “house” image—the one you see in thousands of paintings going back centuries—with the simple triangular rooftop.

Gable roofs allow a house to have a large attic or loft space. Their steep pitch also allows rainwater and snow to cascade off the rooftop easily. They are a relatively simple design, which makes their maintenance and care a bit less expensive than some of the other roofs on this list. Because of their striking shape, gable roofs are a very visible part of a house, so for the sake of your home’s curb appeal, it’s worthwhile to invest in some good-quality shingles.

Note that this style of roof, while great for deflecting rain and snow away from the home, tends to be vulnerable to heavy winds. If you live in an area prone to hurricanes or tornadoes, it’s best to avoid the gable roof style.

Shed Roof

The shed roof has gained popularity in recent years as a trendy, modern type of rooftop, even though the design itself is quite old. As the name suggests, this rooftop resembles the one on a shed: it has a steep pitch, but only in one direction. Because this style of roof is so steep, it’s particularly great at keeping water and snow away from the home. It’s also a tad less vulnerable to wind than gable roofs are, although it’s still not recommended to utilize a shed roof in a part of the country that is vulnerable to hurricanes and tornadoes.

Shed roofs give you a good deal of freedom on the type of shingles you utilize on them. You can lean into the traditional “shed” look and opt for aluminum, or you can give your home a traditional-style boost by opting for more decorative roofing shingles.

Hip Roof

Hip roofs are popular because they allow for more attic space than flat roofs yet are sturdier than gable or shed roofs. However, there is a trade-off for this added stability. This style of rooftop tends to be more complex, and therefore more expensive, than other roofing styles. Hip roofs have four slopes of equal length, all of which come together at the top of the roof.

Besides being sturdy, hip roofs can be very attractive for a home, but they’ll require you to have a good relationship with a professional roofer. This is because maintenance is key for this type of roofing style. It’s more complex, and so minor issues must be tackled quickly before they balloon into more major problems. Even so, it’s well worth the extra investment for this roof, particularly when you make use of good-quality shingles to make your home the most striking one on the block.

Butterfly Roof

Here’s a style that’s truly befitting of modern homes. Today’s homeowner tends to be very conscious of their energy bills, both because of environmental concerns and the skyrocketing cost of heating in some areas. This rooftop, which is so named because it resembles the wings of a butterfly in flight, has two slopes that come together in a “V” shape. This allows for taller walls and, as a result, larger windows. It’s great for heating in the winter and cooling in the summer. The relative flatness of the roof compared to other styles also allows for the addition of solar panels, giving you a further benefit to your energy bill.

Of course, the signature V shape of this roofing style can lead to some issues with regards to water drainage. That’s why it’s important to make sure your roofer waterproofs the entire roof. Water building up will, over time, cause damage, which can ultimately cause the roof to collapse. Fortunately, regular maintenance will help to avert this. Contact Interstate Roofing to get a quote for care and repairs of your butterfly roof.

What Is the Best Roofing Material for Your House?

A roof is one of the most important features of any home. While you may be able to make compromises on other home features, you certainly can’t compromise when it comes to your roof. That’s because shoddy roofing material can lead to cracks, leaks, and other issues. So save yourself the headache down the road by choosing the best roofing material for your home today.

Interstate Roofing specializes in residential roofing installation, maintenance, and repair services. We know the trademarks of quality roofing material. So if you’re looking for the best roofing for your house, we can help you find it. Here are our top picks for residential roofing material.

Composition Shingles

There’s a reason composition shingles are one of the most commonly used types of residential roofing material in the US. For starters, they’re among the most widely available, making them a popular and affordable option.
In addition to being budget-friendly, composition shingles have many other benefits that make them a favorite among homeowners. For example, composition shingles are incredibly durable, which means you’ll often get a good return on your investment.

In fact, in some instances, composition shingles can have a life expectancy of 50 years or more. Because they’re so long-lasting, composition shingles can add to your home’s resale value as well.

One of the reasons composition shingles are so durable is that they’re waterproof, oftentimes fireproof, and weather resistant. They can frequently withstand the weight of snow, as well as hold up during mild to moderate hailstorms.

Composition shingles are also extremely low-maintenance and easy to repair. It’s quite simple to replace individual shingles that become loose or damaged. This means you can avoid the costly expense of a roof replacement if an issue arises. They also require minimal upkeep to maintain their shape and color, another reason they’re loved by so many homeowners.

Speaking of shape and color, another advantage of composition shingles is that they come in a variety of colors and styles. From three-tab shingles to classic timberline shingles, there are a number of options to satisfy even the most discerning homeowner.

One of the few downsides of composition shingles is that they can sometimes come loose in high winds or in climates with abrupt temperature fluctuations. However, these typically aren’t issues in the Pacific Northwest, making our region an ideal climate for installing composition shingles.

Affordability, durability, and versatility make composition shingles one of the best roofing materials you can choose.


Another roofing material we highly recommend is single ply. Single-ply roofing offers many of the same great benefits as composition shingles, such as low cost and minimal maintenance. However, this budget-friendly option will save you money in more ways than one.

Single-ply roofing systems provide long-lasting performance because of their resistance to ultraviolet radiation. However, this benefit has an added advantage. Because of its reflective qualities, single-ply roofing systems also absorb less sunlight than other roofing systems.

This means they can keep your home cooler, thereby reducing your energy costs. Because of their high efficiency and eco-friendliness, installing a single-ply roofing system often translates to increased utility savings.

Single-ply roofing systems are also lightweight, making them an ideal choice for many roof designs. They are an especially good option for flat or low-pitched roofs. The lightweight material also makes installation quick and easy.

As with composition shingles, single-ply roofing systems have the ability to withstand extreme weather conditions.

Making Your Decision

There are many types of roofing materials to choose from, and there are many factors you should consider when making your selection. Some things to keep in mind are your budget, the architectural design of your home, and the climate in which you live.

If you need a roof replacement and aren’t entirely certain which roofing material will work well, call your roofing contractor. A professional will have the experience and knowledge necessary to know what kind of roof will suit you and your home best.

Beyond the Best Roofing Material

One thing to keep in mind is that, regardless of what type of roofing material you ultimately choose, it’s incredibly important to maintain your roof. A well-maintained roof will not only help you avoid costly repairs, but it’s more likely to last longer as well.

Generally speaking, you should have your roof inspected twice a year—once after the warm weather season and again after the cold weather season. This way, you can ensure there’s no damage following any heavy snowstorms or other types of inclement weather. It’s also a good idea to have your roof inspected after a major weather event or if you notice any issues arise, such as loose shingles or signs of sagging.

Interstate Roofing is a one-stop shop for all your roofing needs, from installation to maintenance to cleaning. We guarantee our quality of work by offering workmanship warranties ranging from 5 to 15 years. We also offer lifetime material coverage and transferable warranties if you ever decide to sell your home. To get a sense of the type of work we can deliver, check out our gallery. You can also request a free estimate for your upcoming project.

When things go wrong, the world can sometimes feel like it’s caving in on you. That’s why Interstate Roofing takes great pride in helping people feel secure in their own homes. We want you to use a trusted roofing material that will withstand the test of time and the unpredictability of Mother Nature. So let Interstate Roofing help you find the best roofing material for your needs. With the right roof for your home, you’ll be able to weather any storm.

Low Roof Pitch Options for Your Building

A roof has a “low pitch” if it slopes anywhere from 2/12 to 4/12 inches—meaning that for every foot the roof extends horizontally, the level of the roof rises two to four vertical inches. Some roofs have extremely low slopes and appear to be nearly flat. No roof, of course, should actually be completely flat. If it is, puddles of water will accumulate on the roof and ultimately damage it.

Low-slope roofs are seen on both commercial and residential buildings, although they are primarily associated with businesses. There is a reason for this: in commercial buildings, it is generally considered more prudent to maximize the use of space, leading to a flatter roof. Residential homes, on the other hand, tend to have a much steeper incline for cosmetic reasons.

Regardless of whether you’re looking for low roof pitch options for your home or your place of business, you’ll need to consider what materials are best. In this article, we’ll take a look at the choices available to you and other variables to consider when putting in a roof.

The Trouble with Low Roof Pitch

The primary advantage of a low roof pitch is maximizing space. It will allow you to utilize the space in your area all the way up to the top. This can create a number of advantages. Heating and cooling are easier in a building with a flatter roof, for example. However, low-slope roofs come with disadvantages that don’t trouble steeper roofs. The primary problem with a low slope has to do with drainage: water damages roofs, and water can begin to pool on a roof with too low of a slope. Ice and snow can also be a problem, depending on the climate. If water accumulates on your roof and can’t drain properly, it will eventually cause decay.

Direct sunlight can be another problem for a low-pitch roof, although this is certainly not an issue unique to these types of roofs. In fact, ultraviolet light can do a number on any type of roof, unless the proper materials are used.

This brings us to the primary disadvantage of a low slope roof: you are somewhat limited in the materials you can use to construct them. This is because of the importance of waterproofing. On a roof with a higher pitch, water will easily roll off, and that means you don’t need to concern yourself as much with waterproof materials. A low-pitch roof, on the other hand, absolutely must be waterproofed.


Low-pitch roofs are usually waterproofed through the use of a roof membrane, which can be made from synthetic rubber, a thermoplastic such as PVC, or modified bitumen. Any of these materials can effectively carry water off the roof without allowing it to pool anywhere or penetrate vulnerable areas and cause damage. Occasionally, asphalt roofing systems are also still in use, and while these types of roofs were extremely common in the past, they’ve largely been supplanted by synthetic membranes. This is because asphalt roofs don’t seal as effectively as other membranes do.

Types of Low-Pitch Roofs

There are several options when having a low-pitch roof installed for your building. These options, however, are more limited than those for a gable roof or other higher-pitch roof. Even so, there are several choices you can make as far as the construction of your roof, each with its own set of pros and cons.


Asphalt shingles are, as their name suggests, shingles made from asphalt and layered on your roof over felt, a synthetic underlayment, or thicker “ice and water shield”–type membrane. Shingles can be a controversial option for a low-slope roof. Most manufacturers allow shingles on slopes of 2/12 and greater, but most roofing contractors insist on greater slopes, as shingles aren’t “waterproof” but water shedding. Shingles are popular primarily because of their relatively low cost, ease of installation, and aesthetic benefits. However, installing shingles on a low-slope roof might be asking for problems. Consult a professional roofing contractor with many years of experience.

Single-Ply Membranes

Unlike with other roofing systems, where the material is built up over the membrane or layered on top of other materials, single-ply membranes are installed without the help of other layers. A thermoset or thermoplastic membrane is laid across the surface of the roof (generally over rigid insulation) and hot-air welded together. The most popular materials for single-ply membranes are PVC and TPO, which are usually reinforced with the addition of polyester or fiberglass. Single-ply membranes are a great, relatively inexpensive option that’s easy to install. However, because they’re only one layer, maintenance is critical.

Torch Down Roofing

This roofing system is made from sheets of modified bitumen—a hydrocarbon-based material—which is then sealed to the surface of the roof through the use of a handheld propane torch. The seams of the bitumen will melt and fuse together as a result of the welding process, creating seams that are completely waterproof.

This roofing material is great if you live in a particularly harsh climate. While other materials may expand or contract if the weather is hot or cold, modified bitumen will not. This material also has a long life span and is easy to repair, though it can be extremely difficult to install due to the use of the torch. As most of the roof decks in the Pacific Northwest are made of wood, the risk of fire should be a significant consideration. Only use a contractor with the CERTA certification.

Coated Roofs

For commercial buildings, one of the other popular low-pitch roof options is coated metal. Metal roofs aren’t waterproof in and of themselves, but they can be treated with a coating that makes them so. This coating helps reduce the instances of rust, increasing the life span of the roof. Generally, the coating that’s applied is a fluoropolymer paint, which allows the metal roof to become resistant to water and ultraviolet radiation. This option, of course, isn’t practical for commercial buildings that don’t have metal roofs.

If you’d like to discuss roofing options for your building, contact the professionals at Interstate Roofing. We’ve been serving Pacific Northwest for over 20 years and are always ready to share our expertise.

Do Roof Pitch Styles Affect Material Options or Installation?

Upgrading your roof isn’t something you do every day. Depending on the roof materials you select, you might only invest in a new roof once in a lifetime.

That makes your roof selection an important process.

For many homeowners, the process starts by looking at materials or color. And while both of those are important to create curb appeal, the final selection also depends on your home’s style.

You have many choices when it comes to roofing material selection: asphalt, composite, wood shake, rubber, tile, metal, and more. But it’s more than an economic or color decision; it also depends on roof pitch styles or the slope of the roof of your home.

What is pitch?

Pitch is the term used in the roofing industry to describe the angle or slope of your roof. Roof pitch is comprised of two numbers in the form of a ratio. You’ll see it expressed either with a slash – 5/12 or 8/12 – or with a colon – 5:12 or 8:12. Either way, the numerator and denominator work together to tell you the pitch of the roof.

The numerator refers to the height of the roof.

The denominator refers to the length measurement of the roof.

To keep everything relatable, the industry will always rank with a denominator of 12. Therefore a roof pitch will always be referred to as how much rise there is in the roof over a 12 unit horizontal distance.

For the roof pitch styles from above, for example, the 5/12 means that for every 12 horizontal feet of change, the roof rises 5 feet vertically. For the 8/12, it moves 8 feet in vertical rise for every 12 feet of horizontal space.

With most homes, roof pitch styles range from 4/12 to 8/12, with the lower being a moderate rise and 8/12 being a fairly steep ratio. But roof pitch can have a lot more variation.

A 1/2/12 roof would be almost flat. You might find a low pitched roof on a modern home where the slope is barely there; just enough to allow water to flow. A 12/12 roof would slope at a 45-degree angle. Old Victorian homes often have sharply angled roofs with a steep pitch and, in some cases, they can even move beyond the 12/12 ratio.

Why roof pitch is important?

The roof pitch is important for two reasons.

One, in order to estimate correctly for the amount of material needed for the job, you must have an accurate measurement of the pitch of the roof.

Two, not all materials are suited for the roof. By knowing the pitch, you’ll have a better understanding of the roofing materials that will work best on your home over time.

When a roof is perfectly flat, the calculation for materials is simple: width times length.

As a roof rises, the different pitches require more material to compensate for the slope. The industry has tables for slope factor based on the angles of your home to help determine the extra materials needed. In our examples above, a 5/12 pitch would have a slope factor of 1.085. Use this to multiply with your answer from width times length and you’ll have an accurate measurement of how much material you’ll need.

Roof shapes have evolved over time. Head back hundreds or even thousands of years and you’ll find roofs were made from very simple materials. Straw, mud, grass, wood – only gradually did they start learning the benefits of using different materials and to gently slope the roof for protection.

Flat roofs make sense on some structures. But if you make it perfectly flat, water has nowhere to go. Even a gentle slope is needed for proper drainage. Angles help control the elements and give a building style. But no matter how much you like a particular material, some homes simply aren’t meant for some types of roofs.

Roof Pitch Styles

Low Pitch – these are the safest roofs. They are easy to walk around on and easy to perform maintenance. But they are also more prone to leaks and require more frequent inspections. That’s why you won’t find a lot of low pitched roofs where weather is extreme – both water and snow buildup can be detrimental and put a building at risk. Low pitch is usually the design of choice on modern, sleek, contemporary homes.

Flat roofs cannot be covered with traditional materials such as shakes or asphalt shingles since there isn’t enough pitch to combat damage from wind. Flat roofs are limited to more commercial-grade roofing applications, such as tar and gravel, rubber, or roll roofing.

Medium Pitch – this is where most home roofing systems lie. A medium-pitch gives you ample choices in materials while providing enough slope to keep rain and snow from accumulating on the roof. While it still needs periodic inspections, this is where most roofing choices exist.

If you prefer clay or cement tiles, they can be installed on roof pitches from 2.5/12 up to 20/12. However, for flatter roofs 2.5/12 to 4/12, it is recommended that they are installed with an underlayment to handle the extra weight.

A vast amount of the choices fall into the 4/12 to 20/12 range. This is where asphalt or composite shingles are, which are the most popular types of roofing options on the market today.

If you like the look of wood or slate shingles, they need a more gentle sloping roof, with roof pitches in the 5/12 to 12/12 angles working best.

High Pitch – these are the most expensive roofs to install, but also give dramatic architectural elements. A contractor cannot work on a high pitch slope without safety gear, so more cost will go into it for both repairs and renovation.

Other Considerations

Your final selection will also determine which warranties are in place and how long your roofing materials will last. Be sure to ask about both material and workmanship warranties as the two are often separate.

If green building is important, roof pitch can impact your final selection. Consider both the shingle material and any underlayment necessary to complete the job.

Also investigate fire ratings for the different types of roof pitch styles, especially if you are in an at-risk area.

So what type of house do you currently own? What type of roofing are you interested in? Knowing the roof pitch plays an important part in the selection process; what questions can we answer to help you make your final selection?