Going Green: Concrete for Driveways, Patios, Pool Decks, and Floors

Concrete is one of the most popular building materials on the market for constructing driveways, backyard patios, pool decks, and even interior floors— primarily thanks to its low cost and easy installation. Unfortunately, concrete isn't as clear of a choice in green remodeling circles. While concrete certainly has the potential to be green, the amount of energy required to produce enough cement to meet world demand also means that concrete production is responsible for releasing more carbon dioxide into the atmosphere than just about any other building material. So what's an average homeowner to do? If you choose to use concrete in your upcoming project, making sure it's as green as possible is a great place to start.

Going Green with David Johnston
HomeAdvisor understands that it can be tough for homeowners to wade through all the "green" remodeling information out there, which is why we've teamed up with green remodeling expert David Johnston to provide you with the best, most accurate, green remodeling advice in the business. Johnston is the founder of the green consulting firm What's Working, Inc., the author of multiple books on green remodeling (including the Nautilus Award winner Green Remodeling: Changing the World One Room at a Time), and he happens to know a thing or two about going green with concrete driveways, patios, walkways, and floors. Here's a list of everything you need to know about concrete from a green perspective, drawn from the experience, wisdom, and writings of Johnston himself.

Green Remodeling 101: Calculating Value the Green Way
Before we get to specific suggestions, let's take a moment to look at the cost of going green. After all, budget is a big concern on any remodeling project; and rumor has it that going green can add to your bottom line. The truth of the matter is that green concrete projects are very cost-competitive with traditional ones, and even if they do end up costing you a little bit more, Johnston is quick to stress that the real value of going green is almost always worth more than your bottom line indicates. For example, going green with concrete can reduce home energy costs, lead to healthier indoor environments, and it usually means you'll end up with stronger, longer lasting, lower maintenance slabs. Most importantly, however, going green with concrete flatwork helps to support a more sustainable way of doing things, so you can pass a better world on to future generations. That's the kind of value that's impossible to put a price tag on.

Green Concrete Suggestions for Healthier and More Energy Efficient Homes
That said, here's a list of concrete suggestions from Johnston, starting with how greening your concrete can reduce energy costs and lead to a healthier home.

• Consider Solid Slab Concrete Floors—While concrete isn't necessarily the best choice for the environment, it is an excellent choice as a green indoor flooring material. Once concrete is dry, it emits almost no harmful VOCs into your indoor air, unlike materials such as carpet, finished wood flooring, and vinyl flooring tiles. And if you're concerned about looks, advances in concrete stamping, staining, and coloring can transform the most boring concrete slab into a floor that people notice.
• Reduce Heating Costs with High Thermal Mass—Concrete's high thermal mass makes it a perfect flooring material for areas in your home with lots of windows and a southern exposure. Why? In winter, the concrete floor will soak up passive solar heat from sunlight throughout the day, and then radiate it back into your home long after the sun goes down.
• Install a Radiant Floor Heating System—Concrete flooring is one of the preferred flooring materials if you're considering a radiant floor heating system. In case you haven't heard, a radiant floor heating system is one of the most energy-efficient, clean, and comfortable heating methods around.
• Use Low- or no-VOC Stains When Possible—Concrete stamping, staining, coloring, and acid washing continue to grow more popular by the day. If you do choose to finish your concrete in this fashion, however, ask for a low- or no-VOC, stain if possible, since many staining products can release significant amounts of potentially hazardous volatile organic compounds (VOCs) into your indoor air.

Green Concrete Suggestions for a Better Environment
Healthier, more energy efficient homes are plus, but so is doing right by the environment. Here are a few suggestions from Johnston regarding steps you can take to make sure your new concrete driveway, patio, pool deck, or floor is as environmentally friendly as possible.

• Use Concrete that Contains Recycled Waste—The bad news is that cement production causes eight to10 percent of world CO2 emissions. The good news is that as much as 50 percent of the Portland cement added to concrete could be replaced by recycled waste materials, including fly ash from coal fired power plants, ruse hull ash, and ground blast furnace slag. Even better, these additives can increase the strength, water resistance, and durability of the concrete (though they will slow drying times).
• Reuse Form Boards or Use Metal Forms—Form boards often consist of larger, solid pieces of lumber from old growth trees that get discarded after a single use. If you're undergoing a major concrete project, consider using reusable metal forms, or save your form boards for future use.
• Landscape to Reduce Runoff—Outdoor concrete slabs (especially walkways and driveways) can create large amounts runoff that carry pollutants into storm sewers, and eventually into local water supplies. By liberally landscaping with native plants around concrete slabs, you can reduce the amount of runoff that reaches the street, and you'll be naturally watering your plants at the same time.

Which Shade of Green is Right for You?
While thinking green when it comes to concrete driveways, paths, patios, pool decks, and floors is a smart choice for your pocketbook, your home, and the environment, it's not unusual for homeowners to feel a little overwhelmed when presented with the full scope of green remodeling options. If you're feeling unsure about how green you're willing to go with your upcoming project, there's no need to worry. Going green is not an all-or-nothing proposition, whether you opt for a concrete slab as your basement flooring material, or pull out all the stops with recycled content concrete, metal forms, and a radiant floor heating system to boot.

If you do think green is the right choice for your adventure in concrete, talk with your contractor about adopting a green remodeling philosophy, find a contractor who specializes in green building and remodeling, or seek out the services of a green consulting firm so you can be sure that your new driveway, walkway, patio, or floor project is as green as they come.