San Mateo County · Peninsula
Commercial Roofing in San Mateo County: Peninsula Lab, Office, Multifamily and HOA Roofs
Commercial, lab, multifamily and HOA roofs across San Mateo County: San Mateo · Redwood City · South San Francisco · Daly City.
- Free roof condition report
- Good, better and best bid options
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Bay side and Coastside: one zone, two climates
NOAA's 1991–2020 normals (NCEI) show three different roof environments in one county:
- Bay side, north: San Francisco International Airport averages 19.64 inches of rain a year, with December the wettest month (4.14 inches) and an August average high of 73.4°F.
- Mid-Peninsula: Redwood City averages 19.02 inches, December wettest (3.92 inches), about 86% of it November through March, with a July average high of 81.0°F.
- Coastside: Half Moon Bay averages 26.04 inches, December wettest (5.17 inches), with average highs of only 64.8°F in July and 65.6°F in August.
That's about a third more rain on the coast than at SFO (26.04 vs. 19.64 inches, NCEI), on roofs that stay cool and damp, so drainage, flashing and slow drying matter most there. Mid-Peninsula roofs get more summer heat.
One Title 24 zone
Every San Mateo County ZIP we checked (94401, 94403, 94063, 94065, 94080, 94014, 94015, 94019, 94025) is in climate zone 3 (CEC ZIP list). On nonresidential low-slope roofs, California's Energy Code applies cool-roof requirements when the area replaced, recovered or recoated is more than 50% of the roof or more than 2,000 square feet, whichever is less (Energy Code §141.0(b)2B). The new surface must be a CRRC-rated product that meets the code's reflectance and emittance minimums, and a re-roof over conditioned space in Bay Area climate zones 3, 4 and 12 generally also needs R-23 continuous insulation (BayREN, Table 141.0-C). Recoats are exempt from the insulation rule. The code result is the same county-wide; the exposure isn't. Our Title 24 re-roof guide walks through the trigger, the cool roof values and the insulation rule.
Illustrative image, not a completed project.
Lab and office roofs on the Peninsula
Cresa counts 13.3 million square feet of lab space in South San Francisco at 28.9% vacancy, and 12.0 million square feet at 38.3% in its “San Mateo” submarket, a broker market area rather than the city, and says Peninsula lab leasing is concentrated in those two submarkets (Bay Area Life Science, Q1 2026).
Lab roofs carry exhaust fans, stacks and dense equipment curbs. With vacancy that high, owners re-tenanting space want condition reports and repairs timed to tenant improvements. See roof inspections and condition reports and flashing and drainage.
Multifamily and HOA buildings
The California Department of Finance counts 84,466 units in 5+ unit buildings, 18,736 in 2–4 unit buildings and 27,981 single-attached units in San Mateo County, population 748,182 (January 1, 2026). By city:
| City | Units in 5+ unit buildings |
|---|---|
| San Mateo | 17,778 |
| Redwood City | 11,925 |
| Daly City | 8,539 |
| Burlingame | 6,460 |
| San Bruno | 5,900 |
| South San Francisco | 5,491 |
| Foster City | 5,249 |
| Menlo Park | 4,297 |
| Belmont | 4,191 |
Daly City (5,214) and Foster City (2,795) also carry large single-attached counts, a townhome HOA signal (DOF). See HOA and condo roofing and roofing for property managers.
Permits: city by city, plus the unincorporated county
| Where | What we've confirmed | Source |
|---|---|---|
| Unincorporated areas | County Planning and Building issues a Re-roof Permit, applied for online through its permit center or by mail; the application needs the property address, owner details and the contractor's name, phone and license number. The county says projects in special districts such as Design Review, Coastal Zone and Resource Management get planning review first, so ask whether that applies to your property | smcgov.org, Re-roof Permit |
| San Mateo | Reroof is an Express permit: no plan check and no construction drawings, issued at the counter or online | City of San Mateo, Express Building Permits |
| Redwood City | Roofing permits are reviewed over the counter and submitted electronically through eTRAKiT; construction hours are 7 a.m. to 8 p.m. on weekdays, and weekend work needs a 30-day request and written approval | Redwood City, Plan Review Times; Building FAQ |
| South San Francisco | An over-the-counter permit online, with a city business license required; the city's handout covers the one-overlay limit, in-progress inspection, rooftop equipment access and parapet overflow sizing | SSF re-roofing handout; Plan Submittal page |
Properties inside a city go through that city's building department; the county handles unincorporated areas.
Cities we cover
San Mateo
The most units in 5+ unit buildings in the county (17,778, DOF), about 40% of the city's housing.
Redwood City
11,925 units in 5+ unit buildings (DOF), and the mid-Peninsula's warmer summers (81.0°F July high, NCEI).
South San Francisco
The Peninsula's largest lab submarket, 13.3 million square feet (Cresa).
Burlingame and Foster City
Multifamily and condo stock on the bay side: 6,460 and 5,249 units in 5+ unit buildings (DOF).
Services across the county
Repair & leak response
Leak tracing on multifamily, office and lab roofs, with temporary and permanent repairs.
Replacement
Tear-off or recover, with each city's permit and the Title 24 cool-roof and insulation rules.
Restoration & coatings
Coatings on sound roofs, and an honest answer when a roof isn't a candidate.
Inspections & condition reports
A free roof condition report, including before re-tenanting lab or office space.
Preventive maintenance
Drains and flashings checked before December, when the Peninsula's wettest month arrives.
Sheet metal, flashing & drainage
Scuppers, coping and gutters, where Coastside roofs stay wet longest.
Neighboring counties
San Francisco: north, a single city-county with its own DBI permit rules. See commercial roofing in San Francisco.
Santa Clara County: south, a drier valley in climate zone 4. See commercial roofing in Santa Clara County.
Frequently Asked Questions
Yes. Commercial Roofing Inc. repairs, inspects, coats and replaces commercial, multifamily and HOA roofs in San Mateo County, including Redwood City, San Mateo, South San Francisco, Burlingame and Foster City. Call (408) 770-5992 or request a bid.
San Mateo County Planning and Building issues re-roof permits for unincorporated areas, online through its permit center or by mail, with the owner's and contractor's details and license number. Properties inside a city go through that city's building department instead. Some special districts, including the Coastal Zone, may need planning review first.
Usually. NOAA's 1991–2020 normals show Half Moon Bay averaging about 26 inches of rain a year, versus about 19.6 at SFO and 19 in Redwood City, with summer highs near 65°F. Coastside roofs stay wet longer, so drains, flashing and sealants need closer attention.
Climate zone 3, for every San Mateo County ZIP code we checked, from Daly City to Menlo Park and Half Moon Bay, per the California Energy Commission's ZIP list. Qualifying nonresidential low-slope re-roofs need a cool roof product and, over conditioned space, R-23 continuous insulation. Confirm by address.
Let's get started
Request a bid for a San Mateo County building
Tell us the city, the building type and what you need. Bid invites and plans are welcome. For an active leak, call.
- (408) 770-5992Calling is fastest for an active leak