Homeowners who plan on replacing the roof this summer are faced with one basic question: What is the best choice for my home?

Keith Green, owner of Keith Green Construction in Portland, OR, and Steve Philips, owner of Four Star Roofing based in Hillsboro, offer advice on how to choose the best roof.

Q. How do I know when it’s time to replace my roof?
A. If there’s a leak, it’s probably time, says Philips. Otherwise, “Do a visual check. If it looks nice and flat, not curly, that’s ok. But if you have any questions, have someone come out and take a look. If it’s a wood shake roof, check for discolored shingles, or ones that look frayed or soft. If its a composition (asphalt) roof and there are more granules in the gutter than on the roof itself, it’s time for some repairs.

“If you have a metal roof there’s no real way to tell if it’s bad until it leaks,” he adds. Tile and other materials (like slate) last a long time. It’s the underlayment that causes a problem.”

It’s not unusual for a roof to wear unevenly, he adds. “Keep in mind the north side of the house gets more moss than the south side, but the south side gets more sun and wears out faster.”

Q. My roof is leaking. Can I get a new roof if it’s raining?
A. You can replace a roof year-round, Green says. “In the summer, you can leave the roof open overnight. During the winter, you only tear-down what you can re-do the same day.”

Adds Philips: “If your shoes get soaked in a rainstorm, they’ll be dry in a week. It’s the same thing with a roof. It will dry out. You can put a roof on all winter long; it won’t tear off in a storm. It’s Oregon. If you need a new roof we’ll find ways to do it.”

Q. Can I add another layer to my existing roof or do I have to tear it all off?
A. “If you have a composition roof, you can have up to three layers, but I don’t recommend it,” Philips says. “Some roofs will look ok with three layers — at first — but then after about five years, the top layer will form to the old roof and then it looks bad. You don’t get the same longevity.

“If you have a cedar shake roof, you have to tear that layer off. Then you can put cedar shake back on it, or you can put plywood down, then a composition [or other material] roof,” he adds.

Q. What kinds of roofing materials are available?

Metal Roof, 100% recyclable.

Euroshake rubber roofing, mold resistant.

Cedar shingles.

Composition, most common material.

A. Composition, wood shingles, metal, tile, and slate are some of the more common choices. Composition roofs are the most popular nationwide. Some roofing materials, including composition, tile, and slate, can be re-used, making these environmentally friendly choices.

However, the latest trend is to reclaim rubber tires from the landfill. These are processed into sturdy rubber tiles, eventually yielding a product that is long-lasting and beautiful, says Green.

Q. What are the benefits of a rubber roof?
A. The top advantage of a rubber roof is that it’s “good for the environment,” Green explains. “You take 1,000 tires out of the landfill and put them on your roof. Then the roof can be recycled again when it’s time to replace it.
People who currently have a cedar shake roof benefit most by switching to a rubber roof. Cedar shake roofs have high maintenance costs: Replacement shingles are expensive, as is the labor involved in regularly cleaning and replacing damaged or missing shingles.

Products like Euroshake or Euroslate mimic the look of cedar shake, with “virtually no maintenance. The shingles are mold and mildew resistant; pressure-washing the roof once or twice a year will keep it looking like new.

Q. What kind of roof gives me a better value?
A. Installing a rubber roof costs more up front, Green explains. But in the long run, a rubber roof keeps its value and comes with a transferable warranty that can add value to the home itself.

Philips agrees that while a rubber roof is “beautiful and long-lasting,” he recommends a composition roof to the majority of his customers in the Portland area. Certain kinds of composition roofs are rated to last 50 years, making it a more cost-effective, equally durable alternative to a rubber roof.

Q. How long does it take to get a new roof?
A. If an average-sized ranch-style home has three layers of composition, figure one day for tear-down and one for re-roofing, explains Green. Less than three layers, and it is possible to change out the roof in a single day. If more elaborate roofing products are being used, like metal or a rubber-tile product like Euroslate, figure on as much as a week.

Q. Can roof color help insulate my home?
A. Darker shingles add drama and contrast between the roofline and the home itself. Lighter shingles can soften that same line, creating a more fluid blend between the home and landscaping. But in Philips’s experience, lighter-colored shingles do a better job of reflecting heat away from the surface, which in turn creates a cooler interior.

“It seems to me that after all these years of tearing off roofs, the birch and lighter colors reflect the heat and don’t grow as much moss as the brown, green, or black roofs do. And in the summertime, when it gets very hot, a lighter colored roof can (cool) the attic temperature by as much as 20 degrees.”

Although a rubber roof gets hot, Green says the “honeycomb design on the Euroslate and Euroshake tile acts as an insulating layer and actually helps keep the house cool.” The tiles come in a wide range of colors.

If insulation is the goal, Green also recommends Kasselwood, an interlocking metal roofing system that replicates the look cedar shake. Even though it is made of galvanized steel, Kasselwood qualifies for an Energy Star rating because it helps reflect the rays of the sun back into the atmosphere. “It’s considered a green product because of its ability to reflect light,” he says.

Q. Can a new roof help control the spread of mold?
A. “Mold has been showing up for the last 10 years,” Philips says, adding ventilation, or lack thereof, is the culprit. “Some of those Good Sense homes are built so tight, they can’t breathe, and that’s where the mold is coming from.”

If it’s an older home, installing a new roof is the perfect time to make sure that rooftop ventilation meets today’s more stringent codes. The rule of thumb, he says, is to have one vent for every 300 square feet of roofing. Proper ventilation means air is pulled from the eaves and released through vents located at the hip and ridge on top of the roof. “This will keep mold issues away,” he says, “and it will also make the roof last longer.”

Four Things to Know Before You Raise Your Roof

Keith Green and Steve Philips have four suggestions for homeowners planning to re-roof their homes this year:

1. Get Quotes
Both Philips and Green agree: Homeowners should get several estimates from contractors before starting the job.

“Check them out with the Better Business Bureau, make sure they are a licensed and bonded contractor,” Philips says. If a bid is much lower than the others, be wary of the company, he adds. “It’s easy to cut corners on a roofing job” and save money up front. But in a few years, the work will likely have to be re-done.

2. Get Educated
“Explore the various green building materials that are available,” Green says. “These are good for the environment” and can add value to the home.

Don’t just choose the lowest bid; find out what it covers, Philips says. Will the roofer use plastic or metal vents? Will he replace the flashing on the pipes and chimney? Find out if the roofer will nail or staple the roofing materials in place. Finally, ask about the underlayment (the black tar paper roofers put on prior to installing shingles.) It comes in rolls of 15 lb and 30 lb. Find out which is the best choice for your roof slope.

“It’s a decision-making process,” adds Green. “It’s about finding out what’s out there, then finding out what is best for your home.”

3. Check Referrals
“The biggest asset of my company is my reputation, and I value that more than anything,” Green says. Checking references is important, because “happy, satisfied” customers are the hallmark of a successful contractor.

Who is doing the work is part of the referral question. “We use our own employees, we don’t subcontract the work out,” Green says. “This way you always know who you are dealing with.”

Philip says, “Check out the company itself. Look at their record, talk to their references. Check with the Better Business Bureau. There are about 350 roofers in Oregon. Do your homework before choosing.”

4. Talk Ventilation
Last but not least, “A good roofer will talk about ventilation,” Philips says. It’s a necessary expense, especially if you own an older home. “An improperly vented roof causes condensation, which can lead to [the growth of] mold and other problems.”

It’s important to bring every home up to code, both men agree. “We do quite a bit of upgrading ventilation if there’s not enough there,” Green adds.

And it’s not just about adding more vents. They have to be the right size and located in the right place. Ventilation is about “equal parts of intake and exhaust. If you have 20 vents and only two intakes that’s not going to work,” he adds.