Roof Replacement in San Lorenzo - Free Roof Inspection, Written Price

Fast, Reliable Roof Replacement Across San Lorenzo

A full roof replacement in San Lorenzo typically runs between $14,000 and $26,000 for a standard Bohannon-era single-story home, with most tear-off and re-roof jobs completed in four to seven working days once the Alameda County decking inspection clears. If you’re searching for Roof Replacement contractors who understand what these 1945-1955 tract homes hide under their shingles, we’ve been opening them up long enough to know exactly what we’ll find before the first board comes off. Call (424) 766-4937 to have Erik Lindgren walk your roof and give you a written price before any work starts.

Call (424) 766-4937

San Lorenzo is different from every city around it, and not just because there’s no city hall. The housing stock here was built in a single burst by David D. Bohannon after World War II, which means nearly every Roof Repair - San Lorenzo job we handle sits on the same vintage framing, the same original sheathing, and the same damp low-pitched planes. That uniformity is a gift when you know it well. We do.

Why Birchbark Roofing Is San Lorenzo’s Preferred Roof Replacement Company

Homeowners in San Lorenzo call us because we treat the permit process here as part of the job, not a surprise add-on. Since San Lorenzo is unincorporated Alameda County, every roof replacement permit goes through the Alameda County Building Department in Hayward, not a local counter. There’s no San Lorenzo city hall to file at. A contractor who doesn’t know that loses days waiting at the wrong window. We file county paperwork the same week we sign the contract, so the decking inspection gets scheduled before the crew even stages materials.

Our San Lorenzo customers consistently tell us the same thing: the written change order process is what kept the job honest. When a 1951 roof off Bockman Road opened up and the skip-board sheathing was soft and bouncing, we didn’t keep tearing and hope for the best. We stopped, photographed the rot, priced the replacement boards, and handed the homeowner a written change order to approve before we nailed a single shingle. That’s how a flat quote becomes a real number you can plan around.

Every Roof Replacement in San Lorenzo job includes shoe covers at the door, drop cloths through the hallway, and a clean-up photo before the crew leaves. If your dog needs to stay inside during tear-off, we coordinate the door schedule with you. We use pet-safe product choices where there’s a choice. The Cedarwell Care Promise isn’t a tagline; it’s the list of behaviors we train every background-checked, uniformed technician to follow.

Reroofing in San Lorenzo

Reroofing in San Lorenzo nearly always means one thing: tearing down to the original Bohannon-era decking and replacing what’s rotted before the new roof goes on. But the condition of that decking, and what the county requires us to expose before we cover it, is what separates an honest reroof from a cheap one. The two paths look the same from the street. They are not the same job.

Straight Re-Cover vs. Tear-Off

A straight re-cover, where new shingles go over the existing layer, is sometimes an option. But in San Lorenzo, we rarely recommend it. The north and west roof planes on these older tract homes sit in marine-layer fog until late morning for much of the year, and the original skip-board sheathing underneath often holds moisture that never fully dries. Sealing another layer on top of already-damp decking shortens the life of the new roof and hides deterioration the county inspection would otherwise catch. What looks cheaper on paper usually isn’t.

A typical tear-off reroof on an 1,100 sq ft San Lorenzo home runs $15,000 to $24,000 depending on how much decking needs replacing and which shingle you choose.

What the County Inspection Requires

Because San Lorenzo is unincorporated, the Alameda County Building Department inspects the decking before the new roof can be covered. That’s not a courtesy call; it’s a required step in the permit path. When the old layers come off, the inspector looks at the sheathing, the rafters, and the flashing. If rot or bounce is found, it has to be repaired before the job can proceed. We plan for this, which is why our written price includes a decking allowance rather than assuming the wood underneath is still sound after 75 years.

Flat Roof Replacement in San Lorenzo

Flat roof replacement in San Lorenzo usually involves a home addition, a porch, a carport, or the rear section of a modified Bohannon-style plan that deviated from the original gable design. The job requires different materials, different drainage logic, and a different inspection sequence than a pitched shingle roof. But the same county permit path applies.

Hot-Mop, Torch-Down, or Membrane

For residential flat roofs in San Lorenzo, we typically use either a multi-ply modified bitumen system or, where the client prefers, a single-ply membrane from GAF or CertainTeed. The choice depends on ponding patterns, parapet height, and how the addition ties into the original pitched structure. Because the East Bay’s winter rains arrive as steady, low-intensity storms rather than violent downpours, the main threat here isn’t rushing water, it’s standing water that sits on the membrane and eventually finds a seam.

Expect a flat roof replacement in San Lorenzo to run $12,000 to $21,000 for a typical residential footprint, with the final number written in your contract before any material gets loaded.

Drainage and the Marine Layer

A flat roof in San Lorenzo needs scuppers, downspouts, or interior drains that actually move water. On older homes where a porch was enclosed decades ago, we often find drainage that was never designed for a roof at all. Adding proper slope or drains mid-project is a change order we document and get signed before proceeding. The marine layer that keeps these roofs damp means drainage matters more here than in drier inland cities a few miles away.

Trusted Brands We Service in San Lorenzo

Birchbark Roofing works with materials from GAF, CertainTeed, and Owens Corning, and we keep a local stock of the most common shingle profiles for San Lorenzo’s tract housing so we’re not waiting on a distributor when the decking inspection clears. Whether you choose architectural shingles for a Bohannon-era gable or a CertainTeed membrane for a flat addition, the brand goes on your written quote with the exact product line named. No substitutions without a signed change order. If you’re comparing quotes, ask for the specific shingle model, not just a color and a price.

Common Roof Replacement Problems We See in San Lorenzo Homes

• Soft, bouncing original sheathing on north and west planes. The fog that lingers into late morning keeps these boards damp for decades. By the time we open them up, many have the structural strength of a sponge.
• Multiple re-roof layers trapping moisture. Many San Lorenzo homes have the original 1950s composition shingles buried under one or two later layers. Each layer seals in moisture that the decking underneath never has a chance to shed.
• Flashing failures where additions meet the original roof. Enclosed porches and carport conversions create awkward tie-ins. The flashing at these transitions usually fails first and leaks into the wall, not the ceiling.
• Low-pitched gables that hold moss and algae. The original Bohannon designs used pitch angles that look fine but drain slowly. Combined with the marine layer, this means faster moss growth and earlier granule loss than you’d see on a steeper roof in Castro Valley.

Pricing for Roof Replacement in San Lorenzo, CA

We Also Serve Cities Near San Lorenzo

Birchbark Roofing serves homeowners throughout the East Bay, including Castro Valley, San Leandro, Union City, and Oakland. If you’re just over the county line or a few exits down 880, the same written-price process and Cedarwell Care Promise apply. San Lorenzo remains our core service area, but we regularly schedule crews across the nearby flatlands and foothills.

FAQs About Roof Replacement in San Lorenzo