Metal roofing
Tile roofing
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Flat & low-slopeFree roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Fast, Reliable Roof Replacement Across San Lorenzo
If you own a home in San Lorenzo, chances are your roof was built the same way as your neighbors’: low-slope, minimal overhang, and now well past its intended lifespan. A full roof replacement here is not a someday project. It’s the fix that stops the ceiling stains, the granule buildup in your gutters, and the slow water damage that gets worse every winter. Birchbark Roofing San Francisco crews serve San Lorenzo regularly, and we know exactly what these 1940s and 1950s tract homes look like once the old roof comes off. Call (831) 228-3330 to schedule your free estimate.
Why Birchbark Roofing San Francisco Is San Lorenzo’s Preferred Roof Replacement Company
San Lorenzo homeowners don’t ask us to impress them with jargon. They ask two things: what will it cost in writing, and what happens to my house while the crew is here. We answer both before anyone climbs a ladder. Our written price comes before any work starts, stated in dollars, not vague allowances. And every visit to a San Lorenzo home includes shoe covers at the door, drop cloths through the hallways, and a photo of the completed clean-up before the crew leaves. That’s the Cedarwell Care Promise, and Erik Lindgren holds every Birchbark job in San Lorenzo to it.
We’re part of the Cedarwell family of independent roofing businesses, which has been operating since 2000. Each location is independently owned, and ours serves San Lorenzo with background-checked, uniformed technicians. You’ll know who is on your property before they arrive, and you’ll have a live person on the phone any time you call, day or night. No voicemail tree, no callback three days later.
Our Roof Replacement team has worked on homes throughout San Lorenzo, from the Village to the streets off Hesperian Boulevard and Bockman Road. The roofs are consistent: older composition shingle over skip sheathing, or built-up flat roofs that have been patched too many times. That consistency is why our process works so well here. We know what we’ll find, and we price for it honestly.
Styles & brands we work with
Roof Installation in San Lorenzo
Roof Installation in San Lorenzo usually means one of two things: replacing the roof on a 1944-1958 tract home, or roofing a new addition or ADU. Most calls we get are for the first one. The original roof has reached the end of its life, and the homeowner wants it handled correctly before another rainy season. A typical architectural shingle roof replacement on a single-story San Lorenzo home runs between $13,500 and $21,000, depending on square footage, decking replacement needs, and access.
Full Tear-Off and Decking Assessment
We remove every layer down to the decking. On San Lorenzo homes with original skip sheathing, we almost always find rotted sections at valleys, penetrations, and along eaves. That decking gets replaced before any new roofing goes down, and the cost is written into your estimate as a per-sheet allowance, so you’re not surprised later.
New Underlayment and Ventilation
We install new synthetic underlayment, ice and water shield at eaves and valleys, and address attic ventilation if your 1950s home lacks adequate ridge or eave vents. A roof that can’t breathe rots from the inside out, and that’s a common problem we correct during replacement in San Lorenzo.
Roof Replacement Contractor in San Lorenzo
When you hire a Roof Replacement Contractor in San Lorenzo, you should know three things upfront: the price, the scope of decking replacement, and the warranty. We provide all three in writing before work begins. A full roof replacement on a typical San Lorenzo flat or low-slope roof with built-up roofing runs $11,000 to $18,000. If we’re converting a flat built-up roof to a shingle system, expect the higher end once structural modifications and new drainage are factored in.
Written Pricing Before Any Work Starts
We don’t ask you to trust a handshake. Your written price is delivered before we order materials, and it’s always included, never optional. If tear-off reveals rotted decking beyond the original allowance, we show you the photos, explain the added sheets, and get your written approval before we proceed.
The 365-Day Done Right Promise
Every Birchbark roof replacement in San Lorenzo carries our 365-Day Done Right Promise. If something isn’t done right within the first year after completion, we make it right. No debate, no charge. It’s stamped on every job we do.
Trusted Brands We Service in San Lorenzo
We install and service roofing systems from Owens Corning, IKO, Atlas, and Tamko, among others. For San Lorenzo’s low-slope and flat roofs, we often recommend IKO or Atlas architectural shingles for their wind ratings and granule adhesion, which matters when wind-driven rain pushes across the Bay into minimal eaves. Because we work in San Lorenzo regularly, our crews keep common flashing profiles and decking materials stocked for these older tract homes, so we’re not waiting on a warehouse across the Bay when your roof is already open. Where there’s a choice, we use pet-safe products and adhesives, and we’ll coordinate door schedules with you if the dog needs to stay inside during the job.
See the difference
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After
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After
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AfterCommon Roof Replacement Problems We See in San Lorenzo Homes
- Ponding water on low-slope roofs. San Lorenzo’s post-war tract homes were built with minimal pitch, and after decades of settling, water pools in the same spots every winter. Standing water accelerates granule loss on shingles and seam separation on built-up roofs, and it’s the leading reason we recommend full replacement over repeated patching.
- Rotted skip sheathing under original shake or shingle roofs. We see this most often in the Village neighborhood, where original 1950s shake roofs have been patched over the years. The shakes look fine from the street, but the wood beneath is soft, and once we tear off, the rot is obvious at valleys and penetrations.
- Wind-driven rain getting under worn flashings. San Lorenzo sits close enough to the Bay that winter storms push rain sideways. Worn pipe boots, chimney flashing, and the minimal eave overhangs on these 1950s homes let water in behind the flashings, leaving ceiling stains from November through March.
- Failed built-up roofing layers on flat roofs. Many San Lorenzo homes still have original built-up roofing made of layers of tar and gravel. Once the surface cracks, water seeps between the layers and finds the ceiling below. A roof replacement is the only permanent fix, and it often triggers code upgrades for drainage and insulation.
Pricing for Roof Replacement in San Lorenzo, CA
As of early 2026, full roof replacements in San Lorenzo run $11,000 to $21,000 depending on roof size, pitch, material, and how much decking must be replaced. A standard single-story home with a composition shingle roof typically lands between $13,500 and $17,500. Flat built-up roofs start lower but can climb once you factor in new tapered insulation and drainage improvements. Architectural shingle systems from IKO or Atlas add roughly $1,500 to $3,000 over three-tab on an average San Lorenzo roof. The only way to know your exact number is to have us inspect the roof. Estimates are free, written, and given in dollars before any work starts. Call (831) 228-3330 to schedule yours.
We Also Serve Cities Near San Lorenzo
Beyond San Lorenzo, our crews handle roof replacement in Oakland, Alameda, Moraga, and San Mateo. If you live in one of those communities and the homes share the same low-slope, post-war construction challenges we see across San Lorenzo, we’d be glad to inspect your roof and provide the same written price before any work begins.
Serving San Lorenzo, CA - Our Local Coverage Area
We’re based in the San Lorenzo area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Roof Replacement in San Lorenzo
Because San Lorenzo’s winter problem is wind-driven rain, not snow. Ice and water shield is a self-sealing membrane that seals around nails and prevents water from migrating under the shingles or flashing when rain blows sideways from the Bay. On low-slope roofs, where water moves slowly and sits longer, that membrane is the difference between a roof that leaks in year one and one that holds through the next decade of storms. We install it at eaves, valleys, and around every penetration on every San Lorenzo replacement, regardless of slope.
Almost certainly, yes. Skip sheathing is spaced boards, not a solid surface. Modern shingle systems require a solid deck, so we install new plywood or OSB sheathing over the entire roof area. In practice, on the 1954 Village home we recently replaced, the original skip sheathing was rotted in two valleys and around three penetrations, so we replaced 14 sheets of decking before laying the new CertainTeed architectural shingle system. Your written estimate will include a per-sheet allowance, and any added sheets are priced and approved in writing before we touch them.
Nailing pattern determines how much uplift force your shingles can resist before they tear off. Manufacturers specify either four or six nails per shingle depending on the wind zone. Given San Lorenzo’s exposed position to Bay wind gusts, we use six nails per shingle on most replacements, which raises the wind rating and often preserves the full manufacturer warranty. Fewer nails saves pennies per square but invites blow-off damage in a December windstorm. We won’t do that on your roof.
Converting a flat built-up roof to a shingle system in San Lorenzo generally triggers two things: drainage and ventilation. A shingle roof needs more slope, so we may add tapered insulation or adjust the substrate to achieve the minimum pitch required by code. Second, the attic space must be ventilated to current standards, which often means adding ridge and eave vents. Your roofer should handle these upgrades as part of the permit and inspection process, and the written price should include them. We pull permits on every replacement and don’t hide code upgrades as surprise line items later.
Yes, roofing estimates are priced by the square, which is 100 square feet of roof area. A typical San Lorenzo single-story home is 16 to 22 squares. When comparing bids, look for three things: the decking allowance (how many sheets are included before added costs), whether the quote includes ice and water shield and drip edge, and whether the warranty is written. A lower bid that skips decking replacement or underlayment is not lower; it’s deferred. Call (831) 228-3330 for an exact quote on your San Lorenzo roof. Estimates are free and written before any work starts.
Written by Erik Lindgren, Owner at Birchbark Roofing San Francisco, serving San Lorenzo since our founding as part of the Cedarwell family of roofing companies.