Roofing in the South

Roofing in the South

PART 1HOW’S THE

WEATHER DOWN HERE?

Roofing in the South

When we talk of “the South”, we really mean the entire southeastern portion of the contiguous United States, which consists of Kentucky, Virginia, West Virginia, Arkansas, Tennessee, North and South Carolina, Louisiana, Mississippi, Alabama, Georgia, and Florida. (Some definitions include Maryland and Delaware.)

Generally speaking, the climate in this region is wet and warm, with humid and mild winters. But did you know that since 1970, the South has been getting steadily warmer? In fact, experts estimate that the region’s average annual temperature will have increased by 4 to 9°F by the year 2080.

What’s behind this rise in temperature?

The South is home to some of the most populous cities in the country. With more than 25% of the country’s total population living here, it comes as no surprise that we are responsible for 25% of the U.S.’s total carbon dioxide emissions.

Annual Average Max Temperature (°F)

How’s the Weather Down Here?

Roofing in the South

In 2012, carbon dioxide made up roughly 82% of all greenhouse gases emitted in the U.S. due to human activities. And out of all those human activities, en-ergy use is behind the highest percentage of carbon dioxide emissions in the country, a sizeable chunk (38%) of which can be traced back to electricity use in homes and commercial buildings.

Greenhouse gases are important because they ab-sorb solar radiation and retain the heat necessary to sustain life. But you know what they say about having too much of a good thing. In the case of greenhouse gases, unnaturally high concentrations in the atmo-sphere cause it to retain too much heat, leading to drastic rises in temperature.

Most Common Greenhouse Gases

How’s the Weather Down Here?

Roofing in the South

Should this be a cause of concern for you?

Yes.

As the temperature continues to rise, so will your need to keep cool. And the more energy you use to keep cool, the more you contribute to the greenhouse effect. It’s a vicious cycle that will make itself felt not only in the sweltering heat, but on your wallet as well. Energy is expensive, and having your A/C work overtime to keep your home at a comfortable temperature is bound to cause a spike in your monthly bills.

What can you do about it?

Don’t get us wrong—we’re not suggesting you turn off you’re A/C and take one for the team. We’re saying we ALL need to get smart about how we use and save energy. If it’s going to get progressively warmer over the next 65 years, we need long-term, long-lasting solutions.

And we’re saying your roof is a great place to start.

How’s the Weather Down Here?

Roofing in the South

PART 2IS YOUR ROOF

COOL ENOUGH?A cool roof is a roof that absorbs less heat than conventional roofing materials. Given that we in the South have been told to expect an almost 10° rise in temperature within the next few decades and that a third of the unwanted heat inside our homes comes through our roofs, cool roofs are the way to go.

Roofing in the South

How do cool roofs work?

Think of a cool roof as a light-colored shirt. There’s sound science behind grandma’s “dark clothes for winter, light for summer” tip: light colors reflect most of the sun’s heat and light energy, while dark colors absorb most of it. The less energy your shirt absorbs, the cooler you feel. That’s solar reflectance.

Cool roofs use the same principle to stay, well, cool. That said, while most light roofs are automatically cooler than dark roofs, it is still possible for a dark roof to be cool, provided it still reflects most of the solar spectrum’s non-visible (near-infrared) rays.

And then there’s the principle of thermal emittance, which is how fast a surface gets rid of the energy it has absorbed. The combination of solar reflectance and thermal emittance determines just how cool your roof is.

incident solar radiation

solar reflectance

thermal emittance

heat absorbed

Is Your Roof Cool Enough?

Roofing in the South

How does this translate toreal-world benefits?

Studies have shown that when the sun is out, a conventional roof can reach temperatures as high as 150°F or even higher. Under the same conditions, a cool roof’s surface temperature is lower by as much as 50°F. Assuming indoor temperatures are kept equal, this translates to a reduction in annual cooling costs of 20 to 70%.

CONVENTIONALROOFS COOL ROOFS

94ºF(34ºC)

70ºF(21ºC)

$$$ $$

160ºF(71ºC)

112ºF(44ºC)

102ºF(39ºC)

139ºF(59ºC)

Is Your Roof Cool Enough?

Roofing in the South

How can you make your roof cool?

Some roofing materials are cooler than others, but practically any kind of roof can be made cool during or after installation:

Single-ply membrane roof ▬ prefabricated; choose membranes with integrated solar reflective coatingsModified bitumen roof ▬ apply a reflective white coatingBuilt-up roof ▬ use a reflective surface layer (e.g. white gravel, reflective marble chips), apply a mineral-surfaced cap sheet, or apply reflective and emissive coatingsShingle roof ▬ choose asphalt shingles with specially coated reflective granules or apply cool roof coatings Metal roof ▬ choose metal roofs with factory-applied “cool colored” paint and/or cool roof coatings or leave as-is (metal has high solar reflectance)Tile roof ▬ choose “cool colored” roofing tiles, apply reflective coatings, or leave as-is (roofing tile has high thermal mass and excellent natural ventilation)

If roofing work is out of the question at the moment, you can still reduce the amount of heat coming in through your roof on the cheap by installing radiant barriers, also known as reflective insulation.

Single-layer paper-backed radiant barriers cost around $0.13 per square foot, while multi-layer fiber-reinforced radiant barriers go for $0.30 per square foot. When installed on the underside of your roof, these materials can cut heat gains through your ceiling by 25%.

Is Your Roof Cool Enough?

Roofing in the South

We’ve been talking about how it’s about to get really hot here in the South in the coming decades and what we as residents can do to keep our homes cool without becoming part of the problem. Well, everyone and their mother knows that adding greenery is still one of the best ways to curb climate change. But what of those areas where sufficient real estate for parks, lawns, and gardens is a pipe dream?

PART 3GO GREEN TO

BEAT THE HEAT

Roofing in the South

You’ll have to look up to see the answer. How far up? About as far up as the roof over your head. That’s right, we’re talking green roofs.

What’s a green roof?

A green roof is a living roof. Put simply, it’s a garden on top of a home or building. Where a traditional roof has a protective layer of asphalt shingles or EPDM, a green roof has layers of waterproofing, insulation, root-repellant material, drainage, and growing media topped with vegetation.

Just what kind of vegetation is used depends mainly on what the structure beneath can accommodate. Buildings with low-slope roofs may be able to support intensive green roofs, which are pretty much fully-accessible rooftop parks complete with small trees. Steep-slope roofs, on the other hand, are usually suitable for extensive green roofs with hardy, low-maintenance groundcover.

Go Green to Beat the Heat

vegetative layer

growth media

filter layer

drainage layer

protective layerroot barrier

waterproofing

vegetative layer

growth media

filter layer

drainage layer

protective layerroot barrier

waterproofing

Roofing in the South

How do green roofs help?

Green roofs are ideal in the hot South because they are both reflective and insulating. They can reflect up to 85% of incident solar radiation, and the added mass acts as a thermal barrier to keep outside heat from dramatically impacting indoor temperatures. Think of it as combining two of the biggest benefits of metal and tile roofs.

But there’s more: the plants on a green roof also help cool homes and buildings through evapotranspiration, the movement of water through the plants and their growth media. That alone can reduce your cooling load by 50 to 90%!

And green roofs don’t just cool your home. They also help combat the urban heat island effect, so by installing a green roof, you’re effectively creating a cool oasis right in the middle of your community. Green roofs also:

▬ Double or triple the life of roofs▬ Improve air quality▬ Reduce rainwater runoff▬ Reduce greenhouse gases▬ Provide a habitat for birds, insects, and small animals▬ Increase buildings’ fire resistance▬ improve buildings’ sound insulation▬ Save money

It may be getting hot down here in the South, but starting now, you can take proactive measures to beat the heat and become part of the solution to climate change. Talk to a trusted roofing contractor to discuss your cool and green roof options today.

Go Green to Beat the Heat

Roofing in the South

INSTALLATION COSTSANNUAL

MAINTENANCE COSTSENERGY SAVINGS LIFETIME SAVINGS

starts at $10 to $25 per square foot

$0.75 to $1.50 per

square foot

25% to 70% of heating and cooling costs

up to $200,000

How do green roofs help?

Roofing in the South

PROFESSIONAL ROOFING CONTRACTORS

Shelbyville: 931-536-1818111 Deery Street, Shelbyville, TN 37160

119 Crestland Drive Road Shelbyville, TN, 37160

Murfreesboro/Nashville: 615-800-4990106 South Rutherford Blvd, Suite 2, Murfreesboro, TN 37130

Huntsville: 256-217-54172317 Meridian St., Suite 39, Huntsville, AL 35811

Chattanooga: 423-702-4100633 Chestnut St., Suite 600, Chattanooga, TN 37450

www.ProfessionalRoofingContractors.com