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.

5 Reasons Composition Shingles Are Your Top Roofing Option

When it comes to choosing a roof for your home, it can be easy for you to get confused or feel overwhelmed about which type to pick. You’ll want to choose a roofing option that is the best fit for the structure and that also offers plenty of benefits.

One notable option is composition shingles. These are a type of shingles that have a fiberglass reinforcing mat at the center, which is then coated with mineral fillers, as well as with asphalt. This asphalt coating is what makes the shingles waterproof. The top surface of the shingle is then embedded with a layer of ceramic granules.

So, you may be wondering, what is it about these particular shingles that sets them apart from the rest? Composition shingles are one of the most popular options in modern roofing. In fact, they make up about 85% of home roofing systems. And, when you look at what kind of benefits they provide, you’ll understand why that is.

1. First of all, composition shingles are a very affordable option.

The low upfront cost of these shingles is a major reason why they have become so popular. The cost per square foot is lower than other roofing options, and the framework to hold these shingles is also typically less expensive. This means that you can get high quality and aesthetically pleasing shingles that will not cost you a fortune. Because composition shingles are also typically quite easy to replace, this will further help by cut costs if repairs are ever required.

2. The fact that these shingles are relatively easy to install, repair, and replace is another great benefit.

Contractors have found that it takes less time to install and replace composition shingles than it does for some other roofing options. Once installed, if you lose a shingle, they are easy to repair on a one-on-one basis. Overall, they are also relatively low maintenance.

Since composition shingles are so popular, they are also more readily available. Some less popular roofing options aren’t available in every area, meaning you would have to search to find them or to find a contractor. Fortunately, nearly every roofing contractor will know how to install and repair composition shingles.

3. Composition shingles are also highly durable.

These shingles are known for having a longer lifespan than some other types, often lasting for several decades.

When you choose composition shingles, you can have peace of mind knowing you can count on them for years to come. And over the years, composition shingles will also be able to flex and adapt to a roof’s movements due to expansion and contraction.

The durability of these shingles also means they are great protection against the elements and do not allow for moisture buildup. This is especially great in the Pacific Northwest region, where roofs can take quite a beating from harsh UV rays, lots of rainy days, high winds, and hail.

Composition shingles are also highly flame resistant, which can protect your home from fire damage. These shingles can also help to prevent mold, algae, or fungus from growing.

4. Composition shingles can also be a very eco-friendly choice.

These days, contractors understand that more and more people are looking to do whatever they can to live in an environmentally conscious way. And the materials used to build a home are a major factor in this intention.

When you decide to go with Interstate Roofing for your contractor needs, you’ll find that we offer sustainable roof shingles. This includes shingles that are Energy Star rated. Interstate Roofing is a GAF Certified Green Roofing Contractor and offers many green roofing and home improvement products. Aside from sustainable roof shingles, additional green products the company offers include skylights, solar tubes, and solar-powered vents.

Composition shingles are a greener choice because they help to shield your home from harmful UV rays, which can also decrease your energy costs. CertainTeed, one of the manufacturers Interstate Roofing works with, has sustainable roof shingles that reflect solar energy far better than traditional roofing shingles. The composition shingles themselves can also be recycled.

Interstate Roofing is very committed to going green beyond offering sustainable roof shingles. Unlike other contractors, Interstate Roofing employees will recycle the construction debris, so it doesn’t just end up in a landfill. You can find more information about this commitment to going green and the sustainable roof shingles here.

5. When you choose composition shingles, you get to pick from a variety of options.

A roof, of course, isn’t just for protection against weather and the elements. It is also a key component of a home’s overall aesthetic. Some roofing options only offer one kind of look. However, with composition shingles, you can choose from a wide range of different colors and styles to complement the architecture and landscape of the home as a whole.

Manufacturers are also offering roof shingles that come in “cool colors”, which help to make the roof shingles more sustainable. This is because the lighter colors will better reflect the sun’s rays.

Offering both composition shingles and single ply membranes, Interstate Roofing has been one of the largest roofing contractors in the Pacific Northwest region for over two decades now.

No longer do homeowners just throw up any old roof onto their homes. You are selective and particular, as you should be. You want a product that is durable, long-lasting, green, and looks good, too. At Interstate Roofing, we will help you determine the best composition shingle for your home and you’ll be delighted with the results for years to come.