Intelligent Design
Wedge Roofing’s Tapered System Helps Church Save Funds for Members in Need
by: Nick Fortuna

Section: Features- Winter22

Photo: Wedge Roofing

How many good deeds can one small church accomplish with $120,000? Thanks to the experienced crew at Wedge Roofing, the congregation at The Quest in Novato, Calif., is about to find out.

The Quest, a church and daycare center, saw that some of its members were struggling financially amid the pandemic, so it established the Quest Cares program. The initiative allows church members to apply for small grants to help cover necessary expenses, providing a lifeline for families hit hard by high prices for essential goods and services.

When the church needed a new roof for its 60-year-old building, it reached out to Wedge Roofing, a Petaluma, Calif.-based contractor celebrating its 46th year in business. That decision paid big dividends for The Quest, which saved $120,000 by opting for Wedge Roofing’s tapered roof system over costlier alternatives.


The 12,000-square-foot reroof project included a fully tapered substrate for positive drainage, enhanced rooftop thermal protection and the removal of clerestory windows, all during a threeweek period before the kids in daycare returned from summer break.

The project’s first phase required using a Vector trailer-mounted industrial vacuum to remove aggregate from the existing built-up roof system. All told, more than 45,000 pounds of ballast were removed from the structure, according to Gary Harvey, general manager of Wedge Roofing.

The original construction featured a "dead-flat roof surface," and water would need to be moved 60 to 80 feet in some places toward drains strategically installed at the edge of the roof, Harvey said. Given the roof configuration, the high cost of rigid board stock and months of potential delays due to backlogged orders, the team decided upon a woodframed sloping system.


The design called for Douglas fir studs and oriented strand board (OSB) roof sheathing measuring half an inch in thickness.

"Wedge Roofing is very proud of our scalable, go-to tapered system, which involves readily available lumber and premanufactured, galvanized connecting members," Harvey said. "This system can be configured for any roof shape, any drainage provisions and any size."


Using studs measuring eight feet in length and two inches in thickness, Wedge Roofing was able to raise the system two inches per eight-foot increment by "hanging" the lumber from joist hangers, attached to an initial 2×4 laid on its edge, Harvey said. Then, eight feet back, there would be a 2×6 laid on its edge, followed by a 2×8, and so forth, he added.

"This approach is superior for achieving positive, consistent drainage despite substrate deviations and deflections, as it ‘bridges,’ or is elevated above, any existing roof structural irregularities and provides a continuous, measurable quarter-inch-per-foot of slope," he said. "It may sound difficult, but its simplicity is genius."


All of the attachment points, both to the substrate below and to the individual framing components, were accomplished using readily available Simpson brackets, giving this roof system "off-the-shelf availability," Harvey said. That was a key consideration since supply-chain shocks had resulted in rising prices and shortages of some construction materials.

Despite high lumber prices, the system still was significantly less expensive than other materials designed to perform similarly, Harvey added. Had the church used board stock and a tapered foam design, the additional costs would have strained its budget.


"Additional sloping systems are dependent upon tapered insulation board stock, which, if available, would have meant months of delay in order lag time, and we had only three weeks," he said. "Also, when you’re moving water 50 or 60 feet, the quantity of fill necessary to elevate 7 1/2 to eight inches above the roof surface makes the system incredibly expensive."

After completion of the tapered substrate, Wedge Roofing applied ½ inches of 2.8-pound SPF. The SPF system was protected from the elements by two gallons of high-solid-content white silicone, yielding more than 30 mils of protection, with Lucas Fire White No. 11 granules embedded.

The manufacturer’s representative inspected the project twice – first to examine the tapered substrate for adequate prescribed slope once built, and then upon completion, prior to issuing the 15-year manufacturer’s system warranty.


Wedge Roofing had 15 working days to complete the project but needed only 10. "Under-promise and over-deliver – never fails," Harvey said.

Harvey led a team of 10 installers: Victor Ceja, Guillermo Martinez, Gerado Salcido, Gaspar Penaloza, Edvin Lorenzo, Eric Carreno, Juan Valle, Fortino Juarez, Isidro Landin and Nehemias Lopez. The crew used three Graco E-30 SPF machines with Fusion AP spray guns, two Graco 933 coating rigs with Graco XTR-7 high-pressure spray guns and a Roofmaster trailer-mounted granulating machine.

The materials used included Foam-Lok 2800 closed-cell SPF and Thermo-Sil silicone coating, both from Huntsman Building Solutions.

"High-solid-content silicone has been our go-to coating for over a decade, with no appreciable weather degradation visible from our first system installs," Harvey said.


With measurable precipitation occurring daily in the San Francisco Bay Area, ensuring substrate readiness was critical, whether that meant the plywood substrate prior to SPF application or the SPF itself prior to applying the silicone coating. The crew had varying start times and worked into the evening to maximize thermal gains in temperature, so it covered newly prepared surfaces with Visqueen to ensure a dry surface for the next day, Harvey said.

"The key to a successful foam and coating application in our local environment is to not trap or embed moisture, so multiple engineering controls are put in place," he said. "Nothing is left to chance, no moisture reading is skipped and no control sidestepped – true of every Wedge Roofing project."


For Wedge Roofing, the church project marked another successful partnership with Cal Roof Supply, a Rocklin, Calif.-based supplier. The companies teamed up to earn a pair of 2022 National Industry Excellence Awards, with the other winning project involving the installation of an elastomeric roof coating on a 1960s-era commercial steel building in Santa Rosa, Calif.

The Quest project also was successful from an environmental perspective, Harvey said. With only one existing roof system in place, the current roof system didn’t add to landfills, and it will last for decades, requiring only a simple recoat at some point in the future. The church also can expect to pay significantly less in energy bills.

"When you go from a 1960s non-insulated structure to a contemporary thermal beast, the reduction in utilities will be measurable," Harvey said. "Refurbish and renew – not replace. It’s always a blessing when the client’s values and vision for environmental sustainability and support are hand in hand with ours."