Researchers at UC Riverside say roofs coated with Titanium Dioxide can reduce smog forming pollutants. Engineering students sprayed ordinary clay tiles with titanium dioxide and it removed 88% – 97% of the nitrogen oxide pollution from the air.

Ozone, the main ingredient in smog is created when nitrogen oxides react to sunlight. Nitrogen Oxides are gases that are created by vehicle exhaust, power plants and industrial stacks.

An estimated 21 tons of nitrogen oxides could be removed from the air each day if 1 million roofs were sprayed with titanium dioxide.

Kawaii Tam, a lecturer in UC Riverside Department of Chemical and Environmental Engineering, said “Even a light coating of titanium dioxide can be effective. It would take only about $5 worth of the compound to treat existing roof tiles of an average sized home”.

Titanium Dioxide products on the market now

While there are commercial tiles on the market available now, Tam said they can be expensive and few studies have determined their effectiveness. Most, if not all light colored or white wall and roof paints have titanium dioxide in them to make them opaque and reflective.

White reflective paint is also being used on flat roofing materials to reduce the heat island effect by lowering the roof’s temperature up to 80 degrees. The Lawrence Berkeley Laboratory in California estimates a minimum of 25% savings in energy use for the average homeowner with a roof with a reflective white coating.

Roofing materials tend to lose their reflective properties over time so it is suggested that you provide regular maintenance and remove dust and debris and occasional reapplications from your local roofer.

There is no such thing as a no maintenance roof and that includes a green roof. Even roofs designed to be low maintenance will require 1 or 2 visits a year to remove dead plants and clear gutters and drains.

While some roofing contractors that install green roofs will offer maintenance for a specified period of time, it will be up to you to maintain your green roof. By making a maintenance plan in advance you can keep your green roof alive and thriving. The plan should include a site map, planting schedule, irrigation controls and inspection of plants and run off systems.

Once you are past the initial installation phase and the new plants are established you will need to check the roof at least once a month. Keep a record of soil tests, plants that are thriving and plants not doing so well, weeding schedule and any drainage concerns.

Fertilizing

Some roofs require once a year fertilizing, although it is not preferable to use fertilizers on the roof as run off will affect the local water quality. If rainwater is harvested for your roof, fertilizing will not be needed.

If the vegetation or maintenance brings you to the edge of the roof fall protection systems must be in place.

Before building a green roof, you will need to know the slope, load capacity, roof materials, drainage, waterproofing and water and electrical sources. You can contact a roofing consultant who will evaluate your current roof and help you design a suitable green roof system. Green roofs must also be designed to comply with local regulations.

Four years later the White House has finished installing solar panels on the roof. In 2010 President Barack Obama said solar panels will be installed to provide some electricity and to heat the water. While it took a couple of years, in 2013 the project to install the solar panels finally began. On sunny days, the panels are expected to generate 6.3 kilowatts of solar power.

The first set of solar panels was placed on the roof when President Jimmy Carter was in office. The West Wing offices were equipped with a solar water heating system. Even though Ronald Reagan removed the panels when he took office, President George W. Bush had solar systems installed to power a maintenance building and provide heated water for the pool.

Unable to cover entire roof due to security reasons

Because of security the officials won’t tell how many panels were installed but we do know that the project required drilling down to the concrete on the White House roof then using epoxy glue and threading rods to install a gridded subassembly that the panels could be secured to. The administration won’t say who installed the solar panels or any roofers involved but did say they were American companies.

President Obama is hoping to encourage the private and public sectors to find ways to reduce reliance on foreign energy and cut down on emissions being blamed for global warming. The administration will also devote $2 billion to improve the energy efficiency of federal buildings by 2016.

The energy department has two new efficiency rules, one to cut the energy consumption of new electric motors and walk in freezers and two launch a training program at community colleges to help people enter the solar industry.

Barclays Center in Downtown Brooklyn New York is scheduled to get a green roof. The 130,000 square foot white dome will be covered in a thin soil layer and small green plants. The Barclays arena opened in 2012 and is home to the Brooklyn Nets basketball team. The new green roof will cover the giant Barclays symbol currently painted on the dome roof.

City officials are hoping the green roof will cut down on the noise from the concerts in the arena. Neighbors have complained about the noise and the thumping bass sounds. Complaints from neighbors in Prospect Heights resulted in a $3,200 fine after a Swedish House Mafia Concert.

Tenants be able to look down at a green roof instead of the current reflective white roof

Site development near the arena plans for 15 towers, 3 of which will surround the arena. City officials believe the green roof will be more attractive to potential buyers of the 6,400 apartments planned for those towers. Forest City Ratner Companies owns the Barclays center.

Originally the green roof was going to be a large public park but was scrapped when they ran into financing troubles. City officials believe this will be one of the largest green roofs in the city.

Construction will begin next year for the green roof installation. It is expected to take 9 months to complete, 3 cranes to hoist the green roofing materials up and 6 months for the plants to be seen.

If you have heard about a green or eco roof, or been interested in possibly installing your own, some of the benefits include:

• Decreasing your energy costs

• Cleaning the air

• Reducing urban heat effect

• Beautiful to look at

• Reducing storm water runoff

Your choices may be limited if you want to put a green roof on your existing roof. Although lightweight green roof systems are available, weight is a definite concern. A 20 foot garden can add thousands of pounds of extra weight to your roof. If you have access to the rafters in your attic your local roofer can add reinforcement and lateral supports to shore it up.

Get a Roof Report

Having a structural engineer examine your roof will tell you the load your roof can support and if you will need a roofing company to add support if needed.

Once you have determined the load capacity of your roof, you will want to lay down a water proof liner to protect your home from moisture and also to keep roots from creeping into your roof structure. If your roof has a slope, add a lattice type grid over the liner to keep the dirt and plants from sliding off.

You will need to mix your potting soil with sand or dirt, peat moss or coconut husks and organic matter and usually a water absorbing material to keep the plants from drying out. Your local nursery will probably be the best source of information on the type of soil you will need and the plants that will grow well in your climate.

When considering the vegetation you want to put on your roof things to consider are:

• Amount of work you are willing to put in to maintaining the greenery

• Ornate plants will need more work than moss or sedums

• Wildflowers will attract butterflies, birds and bees

• Grasses will need to be mowed

There are several companies now that specialize in green roof systems, before you invest in your first plant you should make sure your roof can support the added weight.

In Portland Oregon, the Hayden Meadows WalMart’s 92,000 square foot roof is a green roof experiment. 40,000 square feet of the roof is divided into 3 sections each with different soil depths, the rest of the roof is the standard roofing materials for a flat roof for a control section.

Portland State University’s Green Building Research Laboratory will be comparing rainwater absorption and cooling benefits. WalMart gave the university a $133,000 grant to spend the next two years collecting data from the rooftop weather station and sensors in 3 different sections of the roof.

Able to do side by side tests

The students will test the temperatures of the soil to determine if the green roofs lower the urban air temperatures, help reduce the cost to cool the interior of the building and reduce rainwater runoff into the city drains.

Other area agencies are taking advantage of the unique situation of the 3 different soil levels and control section for further green roof studies.

• Portland’s Bureau of Environmental Services also are taking part of the Walmart green roof study by comparing the amount of storm water runoff in the 3 different sections allowing a side by side comparison.

• An environmental consulting company, Cadmus group will be testing the green roof’s cooling properties to determine the efficiency of the buildings air conditioning units.

• Portland Audubon Society will be counting the number of birds that visit the vegetative green roof.

Walmart designed the roof with research in mind to determine if they can cut the cost of doing business. The WalMart spokesperson said they are hoping to determine the best climate for the green roofs to save the most money.