Which roof system is best for residential roofing?

While architecture changes from home to home – Craftsman to Victorian to mid-modern to Tudor – there are basically two types of roof structures: flat or low-sloped and pitched. The decision of what kind of roof system options are available to you depends on what kind of home you currently have or intend to build.

Flat/Low Slope Roofing Systems

Even though they have been used throughout history, flat or low-slope roofs are becoming a sign of ultra-modern modular homes. Never 100 percent flat, these roofs have a slope of/less than 10 degrees. Used as an architectural device for residential homes, flat roofs are more commonly seen in large industrial, manufacturing, or commercial buildings.

Advantages of a Flat/Low Slope Roof System

Although they might seem fancy with a high “cool” factor, the cost of a flat roof can sometimes be more than a peaked roof. However, there are instances where the cost is less. This makes sense – there’s less square footage to cover and fewer materials are needed to build the roof structure itself.

That extends beyond materials as well. The labor involved with flat roof installation can be less as well. Safety is always a concern when working at least 10 feet off the ground. With a relatively level work area, however, work can go much faster. This means less time on the job and fewer labor costs.

A flat roof also allows for more living area. A rooftop garden, al fresco dining, or a place to entertain, flat roofs add more usable square footage to a home. Of course, if you’re planning a roof-top dance party, make sure the roof is able to handle the added weight.

Finally, flat roofs are much easier to service, repair, and maintain to a point. Removing debris, moss, and other roofing material detriments are easily swept away. Visibly damaged areas are easy to take care of because of the access. Smaller repairs may even be handled by the homeowner.

Disadvantages of Flat/Low Slope Roofs

Unfortunately, damaged areas aren’t always visible to the untrained eye. If there is a leak, the water can travel along the slight slope under the roofing membrane before eventually falling. That means the actual issue could be several feet away from where the damage is eventually seen. With no attic, finding the leak can be quite difficult.

This leads us to the biggest problems with flat roofs: longevity. Where pitched roofs have a wide variety of roof shingle materials to choose from, flat roofs are somewhat limited by comparison. Most flat roofs are covered with a membrane or built-up materials.

Man installing a flat roofThese membranes at best last 50 years and at worst need to be replaced every 10 or 15 years. The average lifespan is right around 25 years. These membranes just can’t compete with the lifespan of slate roofing shingles or metal roofing seen on peaked roofs – up to 100 years in some cases.

All of this is to say flat roofs will be leakier in the long run than peaked roofs. Of course, a lot of this depends on how well it is installed and maintained. An experienced roofing contractor that has experience with flat roofs will extend the life of the roof immeasurably. Just as an inexperienced roofer could render a metal roof on a peaked house useless.

Types of Flat Roofing Material

Single Layer Membrane Roof – There are two types of membrane roofs: Thermoplastic and Thermoset. Thermoplastic membranes such as polyvinyl chloride (PVC) and thermoplastic olefin (TPO) can be softened through heating and then hardened by cooling time and time again. Thermoset membranes like ethylene propylene diene terpolymer (EPDM), once the material is hardened, it is irreversible.

Modified Bitumen Sheets – These sheets are in rolls and adhered to the roof decking. Similar to BUR roofs, these sheets are layered. SBS bitumen sheets are applied with hot asphalt or tar while APP sheets are applied with a torch other heat sources. Once installed, the sheets are covered with materials similar to BUR roofs.

Built-Up Roof (BUR) – Also known as tar and gravel roofing, these are sheets roofing felts and play sheets. These fiber infused mats are layered on the roof, covered with asphalt or tar, and then topped with gravel, slag, or mineral granules to protect the layers below.

Pitched Roofing Systems

Much more common than flat roofs, peaked roofs are seen in almost every kind of architectural design. Where water can pool on a flat roof, pitched roofing systems are designed to send the water away from the house through flashing, valleys, and gutter systems.

Unlike flat roofs, peaked roofs require trusses, decking, underlayment, and eventually the roofing material itself. No matter the design of the home or the type of roofing materials, the decking and underlayment are a part of any pitched roofing system.

Advantages of a Pitched Roof System

The most common type of roofing over the last century was the 3-tab shingle. Although it’s become less common than asphalt shingle roofing, it can still be seen on many homes throughout the Pacific Northwest. As such, there are plentiful options when it comes to fixing, servicing, or installing a roof.

For experienced roofers, these shingles are what they started using when working in the industry. Because flat roofs are less common, it may be harder to find companies that maintain or service them. Long wait times may also be the norm when looking for help with a flat roof.

Asphalt shingles are the most affordable option for peaked roofs, but there are many other options to choose from. The rustic look of cedar shakes, the Southwestern feel of clay tile roofing, or the hardiness of steel roofing. Homeowners can immediately change the look of their home based on what kind of roof they choose during a home improvement process.

Improvements in roof coverings also mean lifespans have improved. For those that can afford the most expensive roofing materials, slate tiles and metal roofing offer attractiveness and durability. Architectural shingles are cheaper, but still provide decades of protection for your home, eclipsing flat roof materials. Except for cedar shakes obviously, most of these materials have very attractive fire ratings.

Disadvantages of Pitched Roofs

The most obvious disadvantage is the cost when compared to flat roofs. More square footage, more labor, more materials – just more of everything. All of those costs begin to mount up on a 3,000 square foot home, and that doesn’t factor in the cost of the higher-quality roof covering options.

The pitch of the roof can also make repairs more difficult, which in turn makes it more expensive. Safety considerations become an issue, especially in two-story homes. However, the cost of maintenance and repair can be lessened by paying more money upfront for more durable slate or metal roofing.

For all intents and purposes, the cost of roofing a pitched home and the maintenance is the only disadvantage. But it can be a huge issue depending on your budget. However, unless you are building a new home, the decision has already been made. So let’s take a look at the different roofing materials available for peaked homes.

Types of Pitched Roof Coverings

Asphalt Shingles – Taking over for 3-tab shingles, asphalt shingles are the default choice for many. They come in several colors and designs and cost less than other roofing materials. Improvements in manufacturing also mean longer life – up to 30 or 35 years.

Wood Shingles – Although they are the perfect look for a lakeside bungalow or mountain cabin, wood shingles require a lot of maintenance. They cost more than asphalt shingles with less durability and lifespan (20 years). But it’s hard to overlook the beauty of cedar shakes.

Metal Roofs – Although they can be made to look like cedar or slate shingles, metal roofs are installed in sheets and can be made in a wide variety of colors. Used primarily on industrial facilities, the look of metal is appreciated more and more when it comes to residential applications. This is an expensive option and needs professional installation to reach its full potential. But the potential is impressive: more than 80 years of protection. It’s also the lightest material, causing less stress on the structure.

Slate Shingles/Concrete Tiles – The most durable roofing, slate or concrete is also the heaviest. If planning to use these materials when building a home, make sure the home is built to handle the extra weight. They are also very expensive, can be chipped during installation, and must be handled with care during repair work. However, it’s an impressive look for an impressive home.

Ask The Experts

When it comes to deciding what kind of roof system to choose for your home, there are three considerations to think about: cost, appeal, and longevity. Are you building a forever home? It makes sense to spend a lot at the start for peace of mind in the future. Does a starter home really warrant an expensive metal roof?

All three choices must be considered as a whole when choosing a roof system. It’s a big decision, so talking to roofing experts makes a lot of sense. Warner Roofing and Construction has been working on new builds, performing tear-offs and installations on remodels, and repairing roofs since 1992.

We’re familiar with all kinds of roofing materials as well as installing features such as solar tubes, skylights, and gutter systems to keep the roof system working just as it should. If you have any questions about what kind of roofing would be best for your home, contact Warner Roofing and Construction for a consultation.

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Workers preparing a flat roof covering with a torchmetal roof materials