What we see on Sunnyvale roofs
Most Sunnyvale homes are single-story ranch houses from the 1950s and 1960s, and most of those carry composition shingle. Some original roofs were wood shake, and many of them were later covered with shingle instead of torn off. When a roofer opens up a 1960s roof here it is common to find two layers, old skip sheathing under the shake, and plywood or OSB added during the last re-roof.
Eichler homes are the second big group. Fairbrae, Rancho Verde, Fairorchard, Fairwood and Rancho San Souci in the Cherry Chase area are Eichler tracts built from 1958 into the late 1960s, with roofs that are flat or nearly flat, some with low gables. Those roofs cannot take shingle. The usual choices are sprayed polyurethane foam with a coating, or a single-ply membrane such as TPO, both installed over the original tongue-and-groove decking. Ponderosa Park has similar mid-century homes from other builders, many with low-gable or flat sections.
Concrete tile shows up on the townhome and condo developments built from the 1980s onward, and on some rebuilt homes in North Sunnyvale near Lawrence Expressway. On a tile roof the tile usually outlasts the felt underneath it, so a roof that looks fine from the street can still leak at 30 years.
- Common materials
- Composition shingle on ranch homes, foam or single-ply membrane on Eichlers, concrete tile on newer townhomes
- Typical house age
- About half of all housing units built 1950 to 1979, median year built 1977 (ACS 2024)
- Permits
- Required for every re-roof and for repairs over 100 square feet, applied for before tear-off, with two inspections
- Rainy season
- November through March, with December, January and February each averaging more than 3.5 inches
Roofing services in Sunnyvale
Sunnyvale weather and your roof
Winter rain
Sunnyvale averages about 18 inches of rain a year, and almost all of it falls between November and March. December, January and February each bring more than 3.5 inches on average. The first real storm in November is when a cracked pipe boot or a lifted shingle on a 1960s roof finally shows up as a ceiling stain. An inspection in September or October is the cheapest fix.
Summer heat and sun
The warm season runs from early June into mid October, with average highs in the mid 70s and plenty of hotter days. That is five months of UV on the roof with no rain to cool it. Asphalt shingles lose their granules and curl, and foam roofs lose their protective coating if it is not renewed. On an Eichler, a reflective coating is doing real work, so a local roofing contractor will check its thickness, not just its color.
Wind
Winds here are mostly from the west, and the windier months run from March to early August, averaging around 8 miles an hour, with stronger gusts during the storm fronts that come through in winter. On older shingle roofs, the first things to go are ridge caps and the shingle tabs on the windward slope. On flat roofs, wind lifts loose membrane edges and flashing along the parapet.
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain (in) | 3.15 | 3.3 | 2.39 | 1.09 | 0.54 | 0.1 | 0 | 0.04 | 0.08 | 0.58 | 1.38 | 2.91 |
Where we work in Sunnyvale
Contractors on this site cover the whole city, including:
- Heritage District. The historic downtown around Murphy Avenue and the Caltrain station, with a mix of older Victorian and Craftsman houses, ranch homes, duplexes and newer condos.
- Cherry Chase. Roughly 2,500 homes from the 1950s and 1960s, a mix of ranch houses on shingle and Eichler tracts on flat and low-slope roofs.
- Ponderosa Park. Mid-century single-story homes and bungalows bordered by El Camino Real, many with low-gable or flat roof sections that need membrane or foam rather than shingle.
- Birdland. Southeast of downtown on the Cupertino border, with 1960s single-family homes, including flat-roof Eichlers, plus townhomes and condos.
- Lakewood. Between Fair Oaks Avenue and Lawrence Expressway in North Sunnyvale, single-story Eichler-style homes next to townhome projects that replaced older industrial buildings.
- Lowlanders. A quiet residential area of mostly single-family ranch and Craftsman-style homes, where composition shingle on older decking is the normal job.
- El Camino Real. The commercial corridor that runs across the city from Santa Clara to Mountain View, lined with shopping centers and strip retail on flat roofs.
- Moffett Park. The office, R&D and industrial district north of Highway 237, covering about 1,270 acres of large low-slope commercial roofs.
Permits and licensing
Re-roof permits in Sunnyvale go through the City of Sunnyvale Building Division. The contractor normally pulls the permit; the quote should say whether it is included.
California roofing contractors hold a CSLB C-39 license. Check any license number on the CSLB site before signing. Look up a license.
How it works
1Request an estimate
Call the Sunnyvale line or send the form.
2A local roofer inspects
Roof, flashings, gutters and attic where possible.
3You get a written quote
Scope, materials and price on paper. No obligation.
Commercial roofing in Sunnyvale
Sunnyvale has a large amount of commercial roof area for a city of its size. Moffett Park, between State Route 237, Highway 101 and Moffett Federal Airfield, is about 1,270 acres of office, research and industrial buildings. Most of them sit under flat or low-slope roofs: single-ply membranes, built-up roofs, and older modified bitumen that is reaching the end of its service life. On these buildings the common calls are ponding water near clogged drains, seam failures, and leaks around rooftop HVAC curbs.
Along El Camino Real, which crosses the city from the Santa Clara line to the Mountain View line, the stock is older shopping centers and strip retail on low-slope roofs, many with multiple tenants and multiple penetrations. The shopping centers at Lawrence Expressway and at Fair Oaks Avenue and Tasman Drive are the same kind of building. Commercial roofers listed for Sunnyvale handle TPO and PVC membranes, coatings that extend a sound roof, and tapered insulation to fix ponding. For occupied buildings, ask about work hours, odor control and keeping tenant entrances open.
Sunnyvale roofing questions
What kind of roof goes on an Eichler in Sunnyvale?
Eichler roofs are flat or nearly flat, so shingles and tile are out. The two common systems are sprayed polyurethane foam with an elastomeric coating, and a single-ply membrane such as TPO. Foam adds insulation and seals around pipe and skylight penetrations, but its coating has to be renewed over time. A membrane is more forgiving of foot traffic. Either way, the roofer should check the tongue-and-groove deck for rot first and keep the thin fascia line that gives these homes their look.
Do I need a permit to re-roof a house in Sunnyvale?
Yes. The City of Sunnyvale requires a building permit for every re-roof and for any repair larger than 100 square feet, and the permit has to be pulled before the old roof comes off. Most residential re-roofs can be applied for online through the city's E-OneStop system or in person at the One-Stop Permit Center at City Hall. Expect two inspections, one while the work is in progress and one at the end. A licensed roofing contractor normally handles the application and schedules the inspections.
My 1960s house has two layers of shingle. Can I add a third?
No. California's residential code caps a roof at two layers, and many Sunnyvale ranch homes already have two. The next job is a full tear-off. On a 1960s home that often uncovers old skip sheathing from the original shake roof, so budget for new plywood or OSB over it if that was not done last time. The upside is the roofer sees the whole deck, fixes any rot, and installs new underlayment and flashing instead of nailing over old problems.
The roof is leaking during a storm. How fast can someone come out?
Leak calls are handled first by the roofers listed for Sunnyvale. During a big November or January storm, the first visit is usually a tarp or a temporary patch to stop the water, with the real repair done when the roof is dry enough to work on safely. In the meantime, catch the water, move anything valuable, and do not go up on a wet roof. If you have an Eichler with a flat roof, say so when you call, because the roofer brings different materials.
What drives the cost of a roof replacement in Sunnyvale?
Roof size and pitch, the material you choose, how many layers come off, and what the deck looks like once it is exposed. On Sunnyvale homes the common extras are replacing skip sheathing with solid decking, rotten fascia on the eaves, and bringing attic ventilation up to current code. On Eichler foam and membrane roofs, skylights, parapets and the number of penetrations move the number. City permit fees are separate and should be listed on the quote.
Who handles commercial roofs in Moffett Park and along El Camino Real?
The commercial roofers listed for Sunnyvale work on low-slope roofs on office buildings, R&D space, warehouses and retail centers. Typical work is a roof survey with a photo report, drain and seam repairs, recoating a sound roof, and full replacement with TPO, PVC or modified bitumen when the old roof is saturated. Ask for a maintenance plan. A flat roof checked each fall before the rains lasts much longer than one visited only when it leaks.
Nearby areas
- U.S. Census Bureau, ACS 2024 1-year, Year Structure Built and Median Year Built, Sunnyvale city (Census Reporter)
- City of Sunnyvale, Permit Center and E-OneStop online services
- City of Sunnyvale, Re-Roof Permit Requirements brochure (PDF)
- NOAA 1991-2020 monthly precipitation normals, Sunnyvale 1.9 SE station (CoCoRaHS climatology)
- WeatherSpark, Average Weather in Sunnyvale, California (seasons, temperature, wind)
- Eichler Homes For Sale blog, The Eichlers of Sunnyvale (tract names, years, roof styles)
- Redfin, Popular Sunnyvale, CA Neighborhoods (Heritage District, Birdland, Ponderosa Park, Lowlanders)
- DeLeon Realty, Cherry Chase neighborhood profile
- DeLeon Realty, Sunnyvale North neighborhood profile (Lakewood, Fair Oaks Avenue, Lawrence Expressway)
- CEQAnet, Moffett Park Specific Plan Update, project description
- CEQAnet, El Camino Real Specific Plan, Sunnyvale, project description
- City of Sunnyvale, Village Center Master Plan (Lawrence Expressway and Fair Oaks Avenue centers)