• Flat roofs are beautiful...here's why.
ROOFING
Survival guide for re-roofing your modern home:
useful tips and roof systems to get the job done
From the pages of CA-Modern magazine
By Tanja Kern & Cathye Smithwick
Leaks, weather damage, renovations, old age. No matter what the motivation, there never seems to be a convenient time to install a new roof on your mid-century modern home. And when you finally decide it's time, how will you know which system to choose?
Experienced roofers universally agree that homes with flat or low-sloped roofs are more challenging and far less forgiving than homes with pitched roofs. Consequently, roofs on Eichlers, Strengs, Cliff Mays, and Palm Springs classics by nature lend themselves to a host of unique maintenance issues.
While water will naturally drain off of a pitched roof because of gravity, with flat and low-sloped roofs there are ponding issues, there are draining issues, and both of these woes can lead to leaks and other water damage over time. It's no wonder that many roofers surveyed in the Bay Area say on average that owners of these homes wind up re-roofing every 12 to 15 years.
Re-roofing is not an easy project for a homeowner. Numerous options abound -- and specialists for each type will tell you their system is better than the next. While the tar-and-gravel system is still a viable option for flat and low-pitched roofs, roofing choices have come a long way since the 1950s, when virtually all of our modern homes were originally christened with T&G.
Today, in addition to tar and gravel, a host of newer technologies exist: multi-ply modified bitumen, polyurethane foam, an array of single-ply systems, and of course up-and-coming challengers banging at the door who have yet to be fully tested for longevity.
But there is no perfect roofing solution. Each type of roof offers tradeoffs with respect to cost, insulating properties, longevity, and other elements -- so the 'best' choice for you may not be the same as for your neighbor next door.
How can an average homeowner practically sort out all of these options -- and without suffering a meltdown?
"There's really no book in the library that can teach you about all the different methods of roofing," says Eduardo Peña of Responsible Roofing, a tar-and-gravel company based in Redwood City. "You just have to call up companies and get detailed information about the materials they use."
Finding the right company is also important. "You need to make sure you choose someone who's been around for a long time," says Randy Feriante, owner of Dura-Foam, Inc., a foam applicator located in Menlo Park. "[For best results,] you're not going to go with the cheapest guy. You're going to make sure the guy can do the job."
"Don't listen to one person -- look at different options," adds John Rossi of Cal-Pac Roofing, in San Mateo, who specializes in installations of the Duro-Last single-ply system. "The Eichler Network and the Better Business Bureau -- that's where you're going to find the most reputable people."
The first step in selecting the ideal roofing system and installer for your home is to examine your needs. Begin by asking yourself some key questions:
- How old is my roof?
- Is it in good condition, or are there signs of excessive wear, such as blistering, ponding, or cracking?
- Is repairing an option, or does it make sense to replace?
- How long do I expect to remain in the house?
- Are aesthetics important to me? If so, what look do I prefer?
- Do I want to take a purist's approach (wanting my home to be close to original), or are contemporary options attractive?
- Do I need additional insulation, or is my present roofing system or the insulation underneath it sufficient?
- What is my budget?
If repairing is not an option, then it may be time to replace your old roof; but now you will be faced with other issues to ponder. For example, what type of roof do I want? Should I add insulation? What about adding skylights or upgrading the electrical? Are there other options to consider while my roof is opened up?
Many factors should be considered during the process of choosing the ideal type of roofing for your home. These include cost, waterproofing capabilities of the material and installation method, reflectivity of the top coating (does it reflect light, or hold it in?), weight of the material, presence or absence of seams, and application method.
Given the high cost of energy today, insulation is more important than it was in the past, especially for Eichlers and other mid-century modern homes as originally built 50 years ago. They tend to be 'energy hogs' -- energy inefficient compared to recently built homes.
Roofers are under increasing pressure to develop cost-effective ways to add insulation to roofs, and the most common insulating material is foam. Whether installed as sheeting under tar-and-gravel, single-ply, or modified-bitumen systems, or applied as a spray-coated roofing material itself, two inches of foam can reduce interior summer heat by as much as eight to ten degrees.
Also, in the case of Eichlers, since original electrical systems were installed beneath the roofing material, the re-roofing process offers the homeowner the only practical window of opportunity to upgrade electrical (including wiring for ceiling light fixtures).
Skylights are another option to consider. If you're going to add skylights where none currently exist, re-roofing is the perfect time to do it. The roofing company, or a separate skylight company, can install them.
One Palo Alto Eichler owner reported that he added a room-size retractable skylight in his atrium during a re-roof. He chose foam roofing for the rest of the roof because it sealed tightly around these large openings at the ceiling.
Other opportunities also exist at re-roofing, such as reinforcing seismic stability or integrating plans for tying roof-based solar-electric systems, and air-conditioning and supplemental heating units (such as the foam-encapsulated Unico mini-duct system).
Finally, before finalizing any roofing decisions, investigate rebates that may be available from the city, county, or your local utility companies as a result of increasing your energy efficiency.
The scale and cost of roofing projects for mid-century modern homes really depend on the house. "You need to do a core test [examination of roof samples] before determining how much labor is involved in the project," says Chris Hemphill, Northern California regional representative for Duro-Last Roofing.
What's the condition of the roof? Are there drainage or depression issues? Is there visible damage or leaks? Is the home losing a lot of heat through the roof?
"[Some roofers] talk about insulation when they should be talking about waterproofing the building," Hemphill says. "Each building should be evaluated for its own experience and location. It doesn't make sense to put a lot of insulation on the roof if your windows and doors are leaking."
The price tag is always a factor. Costs can add up when a roof needs to be torn off and insulation added. (If your home already has two roofs, building codes require that you remove at least one layer.)
Shopping around for only the lowest price is not usually a smart move, since different roofing systems, and different installers, for that matter, may offer a different set of values. "Homeowners keep waiting to hear what they want to hear," Hemphill says. "They see a nice guy who gives them a good number, and they feel comfortable. Sometimes you have to bite the bullet and pay for a quality installation. If you don't, you might go to sell it [the house] in six or seven years, and end up losing value on resale."
What's the Best Roof for You?
Here is a breakdown of the most popular systems for homes with flat and low-sloped roofs:
Tar-and-Gravel System
One of the oldest roofing types used in residential construction, the tar-and-gravel system is also commonly referred to as 'built-up' because it involves multiple layers of material. Simply put, installers lay down a base sheet that is nailed in place and covered with layers of felt hot-mopped together with asphalt. The topcoat is then covered with a layer of gravel.
The gravel serves three purposes: protects the felt from the ultraviolet (UV) rays of the sun, improves aesthetics by providing an attractive and uniform surface, and aids in water evaporation by increasing the amount of surface area. However, because of the dark color (and poor reflectivity) of tar-and-gravel roofs, adding insulation to them is strongly recommended. If properly done, this layering process results in a roof that is watertight.
Generally, T&G is the least expensive of the five roofing systems, though the cost will be higher when add-ons, such as insulation and topcoats, are included. Also, some new building ordinances require positive roof drainage in order to pass roof inspection. Such drainage is accomplished by building up the roof with insulating material, which can increase the cost by as much as 50 percent.
A variation on the tar-and-gravel system is the mineral cap installation, which, instead of being topped with loose gravel, uses a material with small rocks embedded in it. "It's used more on commercial buildings," says Responsible Roofing's Eduardo Peña. "But it's really easy to clean, and you can use a blower to blow debris off the roof."
In the Long Beach area, the modern Cliff May Ranchos have their own special needs and expectations. Rochelle Kramer, a Rancho real estate specialist with Re/Max and RanchoStyle.com, says many Rancho homeowners in the 1970s and '80s tore off the original T&G roofs, which had built-in rain gutters, and replaced them with composition shingles and new gutters tacked onto the fascia.
"There were two problems with that," Kramer says. "One, it took away from the originality of the home to put on composition shingle -- a rock roof is the appropriate style for the house. Two, rain gutters detract from the [look of the] roof. And three, we found that the insulation qualities of tar and gravel were better than the composition shingles."
Similar to Peña's mineral cap recommendation, white gravel or rock can be added to a Rancho's T&G to help reflect the sun, aid in energy savings, and ultimately reinforce the original aesthetic.
Sprayed Polyurethane Foam System
Rigid polyurethane-foam sheeting has been used for years as an insulator under tar-and-gravel roofs, as well as with other roofing types. But this material has also risen to prominence as a roofing option in its own right. Spray-on foam, while one of the more expensive roofing options, also offers distinct advantages. "The products are expensive, but it's a savings in labor [over other systems]," says Dura-foam's Randy Feriante.
Finding a quality installer is critical for foam roofs because they are manufactured on site. Foam roofing is delivered through a hose and sprayed on the roof as a liquid. The liquid rises as it cures. Once cured, several layers of elastomeric coating are applied. Elastomeric properties are important, since they allow the coating to stretch as the foam expands and contracts. A gray base coat serves to protect the roof from the UV rays of the sun, while a white topcoat adds reflectivity, making the roof more energy efficient.
Because of the way it is installed, foam can be applied over most existing roofs -- another advantage. However, for roofs with multiple layers of old roofing material, it is recommended to remove some or all of the layers prior to re-roofing. "Our Eichler and Streng people really like foam roofs," says Rick Abril of Abril Roofing. "You can put on all the insulation you want in a roof, and the elastomeric topcoat is a good waterproofer and reflects the sun."
Foam roofs do need elastomeric re-coating, which should be done at least once during the life of the roof. While recommendations vary depending on the manufacturer, most recoat recommendations are between five and ten years after the initial installation.
Edgar Chuang recently replaced the tar-and-gravel roof on his 1,500-square-foot Redwood City Eichler. He says he considered it more environmentally friendly than other options he evaluated because his installer recycled the old gravel. He was also happy that he was able to re-roof right over the existing tar, which kept his roofer from dumping old tar in the landfill.
His advice to homeowners faced with a new roof? "Make sure they cover everything so that the overspray doesn't get on windows, fences, or the courtyard."
Single-Ply Systems
Single-ply systems are composed of sheets of a polyvinyl thermal plastic-like membrane that are mechanically attached to the roof. There are many single-ply manufacturers in the marketplace, and the most prominent in California are Duro-Last, Johns Manville, and IB Roof Systems.
"Single-ply roofing is a waterproof membrane that water can't get through," says John Rossi of Cal-Pac Roofing, who favors Duro-Last. Single-ply membranes are also successful for use as roofing materials because of their proven ability to withstand the ultraviolet rays of the sun.
The membranes are installed as approximately five-foot-wide sheets that are held together by the use of an adhesive. Insulation can also be installed underneath, if desired.
Since single plies are highly reflective, they reduce heat gain. While some homeowners opt for installation without additional insulation, others prefer it to gain cold-weather protection.
Modified Bitumen System
Modified bitumen (pronounced bitch'-you-men) is a membrane-style roof that can be installed as a one-, two-, or three-ply system, though most are two-ply applications. The roof is generally comprosed of a base sheet, plus two modified ply layers. Each layer is attached to one another and sealed using heated asphalt.
Technically, bitumen is another word for asphalt. Modified bitumen is asphalt that has had modifiers added to it, giving it plastic- or rubber-like properties -- things desirable in a roof. Modifiers help to provide more tensile strength and flexibility to the roof, and these qualities are extremely important if the roof is to withstand a building's flexing and moving.
Like single-ply systems, bitumen roofs are manufactured elsewhere, but applied on site. They are assembled on the roof, but manufactured in the factory for quality control.
It is important to cover the top of modified roofs with a protective layer to block out the sun's ultraviolet rays. The roof can be covered with gravel or with a UV reflective granulated surface, with the granulated surface being the lighter of the two. (Homeowners considering a gravel top layer should first be certain that their home can structurally support its weight.)
New Horizons
As in any industry, new solutions are emerging. Although many of the new roofing technologies recently have focused on 'green' roofs, or on those covered all or in part by vegetation and soil, other technologies focus on water repellency.
A curious, recent roofing system discovery is Wetsuit, manufactured by Neptune Coatings, headquartered in Grass Valley. The Wetsuit system is composed of water-based neoprene rubber (yes, the same material used to make wetsuits) and installed in a manner similar to foam applications. The dark-colored waterproof rubber membrane is spray-applied and usually capped with one of a variety of topcoats, including a white elastomeric that meets 'cool roof' standards.
The rubber coating, according to Neptune Coatings, creates a seamless and monolithic system that is waterproof, non-toxic, odorless, free of any solvents or adhesives, and cures almost immediately upon application. The manufacturer even recommends Wetsuit for use beyond rooftop applications -- for foundation waterproofing, and for sealing of ponds, fountains, decks, and shower stalls.
After a dozen years of research, Wetsuit came onto the market three years ago, and today has a handful of certified applicators in California. One of them is Arctic Roofing, also based in Grass Valley, whose sales manager, Mark Ostrov, is optimistic about getting behind such a relatively new product.
"We took on Wetsuit as a product line after 20 years in the roofing business because we saw this product being the best solution for satisfying the flat-roof needs, both commercial and residential," Ostrov says.
Will New 'Cool Roof' Regulations
Impact Your Next Re-roofing?
The next roof on your modern home will be required to have a light-and-bright reflective surface and meet energy-efficient 'cool roof' standards, if the California Energy Commission moves forward to modify the energy laws for residences as it has for commercial buildings.
In an effort to mandate more California residents and businesses to conserve energy, Energy Efficiency Standards for Residential and Nonresidential Buildings, called 'Title 24,' were started in 1978. The standards are updated periodically to allow consideration and possible incorporation of new energy efficiency technologies and methods.
Currently, under Title 24, commercial roofs must have a coating that effectively reflects the sun's energy from the roof surface. It's a standard that may affect residential flat and low-sloped roofs very soon.
These so-called 'cool roofs' are oftentimes bright and white, or at least light enough in color, to reflect heat before it enters a building and directing it back into the environment. By reflecting solar radiation, these roofs also decrease urban heat build-up, raise the area's inversion layer of air, and reduce smog concentrations.
The California Energy Commission is currently considering whether to add reflective requirements to flat and low-sloped residential roofs for 2008, which would be enforced starting in 2009. "If we were really energy conscious," says energy commissioner Art Rosenfeld, "we would apply a regulation to all roofs, including sloped roofs -- but we don't have the courage to do that."
While the pending legislation may not impact installers of foam and single-ply systems, which generally meet 'cool roof' standards, installers of other roof systems that are not inherently reflective are adjusting their methods in anticipation of the new requirements.
"Title 24 requirements haven't hit the homeowner yet," says Orlando Guastella of San Rafael's Aussie Roofing, who installs modified-bitumen, "but at any time, we can add a white 'green' material [with 'cool roof' qualities] to an emulsion, and paint over the modified installation." Similarly, tar-and-gravel roofs can achieve varying levels of reflectivity with white gravel, or with the mineral cap system, common on commercial roofs.
Nearly a third of the electricity consumed on a hot summer afternoon is purchased to keep buildings cool. California's energy supply challenges are being driven by a shortage of power during these peak periods. "A 'cool roof' can reduce these significant electricity-consumption levels in any one building by as much as 40 percent," says Adam Gottleib, information officer for the California Energy Commission.
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• Flat roofs are beautiful...here's why.
Photos: David Toerge, Michael Greene, Don Kellogg, Rochelle Kramer; and courtesy Abril Roofing, Inc., Dura-foam, Inc., Duro-Last Roofing, Inc., Neptune Coatings Corp., Chris Hemphill
For your next roofing project, consider the Eichler Network's roofing team of 'Preferred Service Companies':
• Abril Roofing, Inc. (foam): abrilroofing.com
• Aqua Stop (rubber roofing): 707-753-0550
• Aussie Roofing, Inc. (modified): aussieroofing.com
• Cal-Pac Roofing (single-ply): cal-pacroofing.com
• Done-Rite Roofing (single-ply): 916-801-6550
• Dura-foam, Inc. (foam): dura-foam.com
• Responsible Roofing, Inc. (tar & gravel): 650-569-5980
• State Roofing Systems, Inc. (single-ply): stateroofingsystems.com
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