Category Archives: roofing materials

Flat Roof Materials & Installation Costs 2020: PVC vs. TPO, EPDM Rubber, BUR, Modified Bitumen, Spray-on Coating

When it comes to covering up a flat roof, your options are both limited and expansive. What that means in a nutshell is that your traditional roofing materials such as asphalt shingles, concrete tiles, and corrugated metal are out of the window. That being said, flat roof systems such as PVC, TPO, EPDM rubber, and others, each have their distinct pros and cons.

EPDM Rubber installed on a flat roof by GemTile

So why can’t you put traditional roofing materials on a flat roof? Well, technically you can, but they are almost guaranteed to leak! πŸ˜‰

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Systems like asphalt shingles and concrete or clay tiles are installed by overlapping one row on top of another. They work cohesively with the pitch of the roof to shed rainwater and snow as it falls from the sky. Since flat roofs have little to no pitch, the water would work itself underneath the shingles or tiles, eventually rotting the substrate and causing leaks on your interior.

Covering a flat roof is a whole different animal than shingling a pitched one. On a flat roof, generally speaking, you want to avoid any types of seams, if at all possible.

The biggest threat is of course going to be water, which WILL find any access though any hole or inadequately-sealed seams in the roofing membrane.

Your main goal when covering a flat roof is to create a barrier that will be impenetrable to water.

How do you make an item (besides a roof) impenetrable to water? You can either apply something physical such as a tarp, or coat it with a material to create a barrier like you would via deck stain or lacquer. Roofs follow this same premise –- either physically cover it with something like a PVC membrane or apply a coating such as tar or spray on silicon.

Flat Roof Costs:

It’s easy to assume that a flat roof would be far less expensive to apply material to than a pitched one. For access reasons alone it would seem it’s a lot easier to roof a flat surface than one that is steep and requires a harnesses and braces to move around.

Install Roof Shingles

$7,500
Average price
Install Metal Roof

$14,500
Average price
Install Flat Roof

$8,225
Average price

See costs in your area Start Here - Enter Your Zip Code

Many roofing contractors will tell you though that working on flat surfaces is actually harder on the back.

Take into account that flat roofs often require the application of adhesives and some types such as modified bitumen are installed with a torch that heats up the seal.

Installation costs can be just as high for a flat roof as they would be a 10/12 pitch.

Labor prices will vary depending on your area. You can get a good idea of the estimated cost to cover your flat roof based on the average material prices.

  • PVC Membrane – aside from the membrane itself, an insulation board must first be installed to provide a suitable substrate and to help with the energy costs. The membrane is typically installed in rows comprised of six foot wide PVC membrane, plus an overlap of 6 to 8 inches. Each row of rolled membrane must be mechanically attached and hot-air welded at the seams with overlapping rows of PVC membrane.

    Immediately next to the roof edge and throughout the outer perimeter of the roof, a three foot wide PVC membrane is used to help prevent the wind uplift.

    The edges of each row are mechanically fastened (using plates and screws) to the roof deck before the seams are hot air welded to help prevent uplift.

    Some installers will employ a fully-adhered or glued to the roof deck rather than mechanically-attached installation method to help prevent wind uplift. All else being equal, the fully-adhered membrane will cost more than mechanically attached one.

    All in total, the installation of a PVC roofing membrane such as that from IB Roof (residential and commercial vendor) or Sika Sarnafil (mostly commercial vendor) will cost between $7.50 and $12.50 per square foot, depending on the membrane type, scope of the project, roof accessibility, and project location.

  • EPDM Rubber – manufacturers try to avoid seams with EPDM membrane sizes that can reach 50′ wide by 200′ long. These huge pieces are great for avoiding possible leaks at the seams, but these wide rolls are also very difficult to handle during the installation.

    EPDM membranes install like a giant sticker, but this must be done slowly and with precision to avoid air bubbles.

    Typically, EPDM rubber will cost between $6.50 and $10.50 per square foot installed.

  • TPO – insulation boards are first fastened to the roof substrate. TPO also comes in rolls and can be mechanically fastened to the insulation boards or installed with the self-adhesive. Costs are approximately $6.50 to $10.50 per square foot installed.
  • Modified Bitumen – modified bitumen is installed in multiple layers, each of which is torched to the surface below at every ΒΌ turn of the roll. This is a very labor intensive process that absolutely must be performed by a professional. This type of roof does have cold-rolled technologies available now as well, but it involves a lot of application of roofing tar. Estimated costs are $4.50 to $8.50 per square foot installed.
  • Built Up Roof – installation includes applying multiple layers of ply sheets that are bonded together using hot asphalt. The top layer can be a reflective coating for energy efficiency or gravel for added durability. Costs range from $6.50 to $9.50 per square foot installed.
  • Spray-On Roof – applying a spray to a roof sounds easy. The material can be applied right over an existing roof so little to no prep work is needed besides cleaning. It’s still important to apply the spray evenly and delicately though.

    The material itself will also determine the cost as polyurethane foam can be applied for as little as $3.50 per square foot and acrylic $6.50 per square foot.

    Silicon is the agreed upon premier spray application, but the material costs can drive installation prices up to $7.50 to $12.50 per square foot or more.

Choosing an appropriate flat roofing material is a two-part process. On one hand you want a substance that has nice aesthetics while fitting within your budget. You also want to know the product will last:

Materials Life-Span

The life span of your flat roof depends on a lot of different factors starting with proper installation. If your climate has rapid changes that see Spring, Summer, and Winter in the same week, the material will be put under more stress which will reduce its life span.

A roof that is accessed a lot will also wear down faster. Here is what you can expect from the popular materials in terms of longevity:

  • PVC – 15 to 30 years.
  • EPDM – 10 to 15 years.
  • TPO – 7 to 20 years.
  • Bitumen – 10 to 20 years.
  • Built Up Roof – 15 to 20 years.
  • Spray-On – up to 20 years.

Why Do Flat Roofs Exist?

Before we get into comparisons of different flat roofing materials, it’s important to know why they exist in the first place since they’re seemingly such a hassle and an almost-immanent leak threat.

There are two main reasons behind why a contractor would call for a flat roof: 1) aesthetics and 2) convenience.

For example, when you’re adding on to a home (building an addition) with something like a three-seasons room, a flat roof simply looks nicer. Homes with unblended roof pitches can be an awkward eyesore.

In commercial buildings, flat roofs, outright, offer a more convenient place to install outdoor HVAC units rather than putting them in high-traffic ground areas.

Of course, any roof’s main job is to create a barrier of protection between the building below and the atmosphere above. Therein lies the conundrum associated with flat roofing. For all the aesthetics and convenience, the design doesn’t do a lot to avoid snow and water buildup.

To be fair, flat roofs aren’t completely ‘bubble-level’ flat. They work in much the same way as a gutter system, angled slightly or pitched a couple of degrees, so that water can flow into a downspout. Even so, flat roofing materials need to be able to absorb the brunt of the weather and to withstand ponding water or snow and ice until it melts.

Pros and Cons of Common Flat Roof Membranes

Whether you have a commercial or residential building, some type of roof covering is 100% mandatory. There are generally 5 to 6 different routes to take regarding the materials needed for roofing a flat surface:

1. PVC
2. EPDM
3. TPO
4. Modified Bitumen
5. BUR
6. Spray on Coating

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Roofing Shingles Vs. Cedar Shakes Costs, Plus Pros & Cons in 2020

In this guide, we present a side-by-side comparison of cedar shingles and shakes vs. asphalt roofing, with focus on on material composition, installation costs, plus pros and cons and ROI of each option. Let’s get started!

The Difference Between Wood Shingles & Cedar Shakes

When used in roof covering, wood can be either shakes or shingles. Wood shakes have been used for centuries. They are split from logs and often left as split to retain the textured, rough-hewn effect.

Cedar shakes around a skylight Source: Kuhl’s Contracting

A wood shake is instantly recognizable by its thick butt end. With the advent of commercial sawmills a wood shake was often sawn after splitting to achieve a uniform back side.

These sawmills also produced a completely uniform product with an even taper and identical thickness by sawing shakes on both sides. This manufactured product is known as a wood shingle.

California redwood, western red cedar, cypress, spruce and pine are all used to manufacture wood shakes and shingles. Cedar is the most popular wood for shakes, southern yellow pine is also popular. Wood shakes and shingles can be pressure treated with fire retardants and chemical preservatives.

Types of Asphalt Shingles

Asphalt or composition shingles are most commonly constructed from organic material or fiberglass. Asphalt shingles are built upon a base or mat that was originally made of absorbent cotton rags.

Roofing Shingles Display

Later, more readily available wood pulp or paper replaced the natural fibers. Asphalt was poured onto that base, known as “felt”.

In the 1970s, fibrous glass was introduced, which did not rot like the organic materials. Today, 95 percent of asphalt shingles feature fiberglass felt.

Cedar Shingles/Shakes Cost Vs. Asphalt

In the roofing industry, an 18-inch wood shingle is referred to as β€œPerfection” and 24-inch wide shingles are known as β€œRoyal.” A wood shake is a premium product, costing around $3.50 per square foot versus $2.50 a square foot for wood shingles.

Cedar Shakes Siding and Asphalt Roof By Red House Architects

The most expensive option for shingling a roof is wood shakes — between $7.50 to $12.50 per square foot or $750 and $1,250 per square (100 square feet), installed.

Cedar Shakes Roof By Linda McDougald Design

Wood shingles are slightly less pricey at $6.50 to $10.50 per square foot or $650 to $1,050 per square, installed.

For comparison, asphalt roofing can cost as little as $3.50 to $5.50 per square foot or $350 to $550 per square, installed.

Roofing Shingles Installation

Install Roof Shingles

$7,500
Average price
Install Metal Roof

$14,500
Average price
Install Flat Roof

$8,225
Average price

See costs in your area Start Here - Enter Your Zip Code

So, why do homeowners opt for the much more expensive wood shingling? The answer is…

Aesthetics

It is hard to beat the appearance of a natural wood roof. If you are making over a traditional older house, cedar roofing is probably the historically appropriate choice. Not that asphalt shingles are an unattractive alternative.

Asphalt shingles come in a wide variety of colors and shapes and patterned asphalt roofs can be eye-catching in their own right.

Beyond looking great, wood shingling does not win many comparison battles with its asphalt-covered competition. Let’s explore some of the pros and cons up on your roof…

Longevity

Life expectancy for both asphalt and wood shingles is a tricky matter. Let’s tick off all the factors that can affect the longevity of a roof covering: quality of installation, diligence of maintenance, quality of materials, age of the house, overhanging trees, climate and foot traffic.

Chemically treated wood will outlast untreated shakes and shingles and a shake will survive longer than a shingle. Both asphalt and treated wood shingles can survive up to 30 years on a roof, given ideal conditions.

Durability Cedar shingles are resistant to insects but not large amounts of rain. Cedar shakes in a damp environment are susceptible to mold and mildew and rot.

Sap from overhanging trees will encourage mildew. When rot sets in it has likely affected more than a single shake and the entire roof is a candidate for replacement.

Cleaning Costs

Asphalt has its own weather issues. Algae is more likely to take hold on an asphalt roof than cedar shakes. While this will not hamper your roof’s protection abilities, it does lead to unsightly staining and premature replacement on appearance grounds, especially at resale time.

Cleaning either a asphalt or wood shingle roof with a solution of water and bleach applied professionally and gently with a powerwasher will run from $25 to $30 per square. And this is a job best left to competent professionals as a poorly handled powerwasher can wreak havoc on roof shingles.

Flammability

Some building codes where fire is a danger restrict or ban the use of wood shingling altogether. Asphalt shingles have a high resistance to flames.

Keep in mind that wood shakes and shingles can be pressure treated with fire retardants and chemical preservatives.

Wind and Impact Resistance

Cedar shakes and shingles are the clear winner here. Both have proven to be highly impact-resistant and have tested to withstand wind speeds of up to 245 miles per hour (which your house will never see).

Asphalt shingles will, however, blow off a roof in high winds. Fallen branches are also much more likely to damage an asphalt shingle that a wooden one.

Maintenance

Cedar is a high maintenance material. For starters, the wood needs to breathe and the roof must be kept clear of leaves, branches and debris.

Gutters must be regularly cleaned and ventilation kept open for air to flow around the shakes and shingles.

Topical treatments can be applied as water repellents and ultraviolet inhibitors that can prevent graying of a roof.

If individual shakes or shingles are required they will match the composition and color of the original roof – score one point for cedar.

While algae will not impair the performance of asphalt shingles, mosses that grow on a damp roof can cause the edges to lift or curl leaving them vulnerable to a blow-off in storms.

Moss can be removed with a 50:50 mix of laundry-strength liquid chlorine bleach and water soaked with a low-pressure sprayer.

The moss will eventually loosen and can be swept off the roof. It will return, however, if many of the same measures as keeping a wood roof dry – trimming tree branches, removing debris and clearing gutters — are not followed. Replacing individual shingles is often a DIY job.

ROI, Property Valuations, and Curb Appeal Considerations

In terms of property valuations, replacing a cedar roof with asphalt will instantly diminish the value of your property. — On some historic homes, as well as homes surrounded by other homes roofed with cedar, such as in historic districts/neighborhoods, this may not even be an option to begin with.

However, if you must replace a cedar roof with something else, then opting for a metal roof rather than asphalt will help preserve the valuation and curb appeal of your property.

Conclusion

On the cost and maintenance considerations – the β€œBig Two” for most homeowners – asphalt shingles are the clear choice over wood shakes.

And in fact, about 70 percent of American roofs are covered with asphalt shingles today. On the other hand, those wood shingled-roofs just look so darn good, don’t they? πŸ˜‰


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TPO vs. PVC Roofing Cost in 2020, Plus Pros & Cons

If you are looking for a cost-effective and durable single-ply roofing system for your flat or low-slope roof, a TPO (thermoplastic olefin) membrane may be a solid, energy-efficient option.

TPO membrane installation

Cost

A typical residential TPO roof will cost between $6.50 and $11.50 per sq. ft. installed. Thus, for an average-sized 1,200 sq. ft. flat roof, your total cost to install a new TPO roof can range from $7,800 to $13,800, depending on project specific variables, contractor choice, and your home’s location.

The above cost assumes a low-slope roof on a single-story or two-story house, the cost of materials and supplies, removal and disposal of up-to one layer of existing material such as EPDM rubber, permitting, installation, and a 5 year workmanship warranty.

Note: the cost can be significantly higher in expensive metro areas and on complex flat roofs that involve additional work and/or are difficult to access.

Install Roof Shingles

$7,500
Average price
Install Metal Roof

$14,500
Average price
Install Flat Roof

$8,225
Average price

See costs in your area Start Here - Enter Your Zip Code

Did you know? TPO membrane can provide combined benefits of both, EPDM rubber and PVC roofs, but at a more economical cost than PVC.

It’s therefore not surprising that TPO roofing systems are quickly growing in popularity and demand, in both residential and commercial flat roof markets.

TPO in a Nutshell

flat-roof

A TPO membrane is made from ethylene propylene rubber. Special technology is used to chemically bind together, rubber, ethylene ( an organic gaseous substance) and propylene (a byproduct of petroleum refining). At the end, numerous filler materials are added, such as talc, carbon filler and fiberglass. — These fillers reinforce the TPO membrane’s strength and durability.

Did you know? TPO roofing membrane has been specifically designed to have the advantages of a rubber roof, combined with hot air-weldable seams for extra durability.

TPO membranes have been manufactured in the US since the early 1990’s and are now the fastest growing segment of the US single-ply roofing industry.

TPO Membrane Options

TPO roofs are manufactured to meet a variety of needs and design specifications. They are available in white, light gray, and black colors. White TPO roofs offer the best solar radiant heat reflection properties, hence they are the most popular choice thanks to their energy-saving potential.

Single Ply Membrane on a Residential Flat Roof

For most residential applications, TPO membranes come in two thicknesses options: 45 mils (.045β€³) or 60 mils (.060β€³). The width and length of the membrane can vary depending on the manufacturer, with a typical TPO membrane roll being 6 to 6.5 ft. wide and 100 ft. long.

Other membrane thicknesses and widths are also available depending on the manufacturer, including a 3 feet-wide rolls for the edges of the roof. Commercial grade TPO membranes may have a thicknesses of up to 80 mils (.080β€³) and may come in up to 12 feet-wide rolls.

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