Free roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Before
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AfterFast, Reliable Roof Repair Across Half Moon Bay
Roof repair in Half Moon Bay usually costs between $395 and $1,850 depending on what failed, and most smaller fixes are done in one visit. That’s the honest range we quote before work starts. If you have a leak, missing shingles, or rusted flashing anywhere from Frenchmans Creek to the bluffs near Pillar Point, call us at (743) 200-8347 and a real person answers. You’ll get a written price before a single nail goes in, and a written guarantee with every repair.
We know this stretch of coast because we work it every week. Same salt air, same moss, same wind-driven rain that finds every weak spot in a roof. Our Roof Repair crews carry what Half Moon Bay roofs actually need: stainless flashing, algae-resistant underlayment, and marine-grade fasteners. Not what a supply house in Redwood City stocks for inland tract homes.
Key Takeaways
- Half Moon Bay roof repairs must account for salt-air corrosion and persistent marine-layer moisture that inland roofs never face.
- Written pricing comes before any work, in every case. No exceptions.
- Every repair includes a written 365-Day Done Right Promise. If it fails within a year, we return and make it right. No charge for the second visit.
- The technician’s name and photo are sent to you before they arrive. They show a photo ID badge at the door. Every time.
- Expect $395 – $1,850 for most repairs. Larger repairs involving decking replacement or valley rebuilds run higher, and you’ll know the number before we start.
Why Mercer Roofing Is Half Moon Bay’s Preferred Roof Repair Company
Half Moon Bay homeowners call us because the failure mode here is different from anywhere 15 miles east. We’re the company that accounts for that difference in writing, before work starts. Founded in 2000 and part of the Threshold Group family of home-service companies, Mercer Roofing built its reputation on a simple standard: background-checked, identity-verified technicians who show up in a marked uniform with a photo ID badge. You know exactly who is walking up your driveway before they knock.
Grant Whitlock leads our team, and the standard doesn’t change from job to job. Every repair gets a written guarantee. Every repair gets a written price first. If the work isn’t right within 365 days, we come back. No arguments, no invoices for the return trip.
Response time to Half Moon Bay matters because the marine layer doesn’t give roofs time to dry. When a leak opens during a winter storm, waiting two weeks for a roofer means soaked insulation and framing. We schedule repairs across El Granada, the Main Street corridor, and the coastal neighborhoods weekly, so we’re on your roof within days of your call, not weeks.
Beyond the coastal exposure, we know the housing stock: 1960s – 1980s ranch-style and split-level tract homes along the flats, plus older wood-framed buildings along Main Street with low-slope roofs and decades of moisture in the decking. That local knowledge means we open the right sections the first time instead of guessing.
Commercial Roof Repair in Half Moon Bay
Commercial Roof Repair in Half Moon Bay means working on low-slope and modified bitumen roof systems that have taken years of salt fog, moss pressure, and horizontal winter rain along the coast, and the difference between a patch job and a real repair here comes down to materials and how the repair is flashed. A commercial roof repair in Half Moon Bay typically runs $850 to $3,400 depending on the size of the affected area, the condition of the underlying decking, and whether we’re rebuilding flashing around curbs, drains, or penetrations. You’ll get that number in writing before we start.
Low-Slope Leak Repairs
Most commercial leaks we find in Half Moon Bay trace to failed flashing at drain sumps, HVAC curbs, or parapet walls where salt-laden moisture has eaten through galvanized metal. We cut out the rotted section, install stainless or aluminum replacement, and re-seal with a cold-applied reinforced membrane. The repair is documented with photos, so the building owner has proof the work met coastal exposure standards.
Moss and Ponding Water Removal
On commercial roofs along the coastal flats, moss grows into drainage paths and creates ponding water that finds every seam and lap. We remove the growth, re-slope the roof surface where practical, and install algae-resistant membrane in the affected zone. The repair is warrantied for 365 days, and we put that in writing.
Roof Leak Repair in Half Moon Bay
Roof Leak Repair in Half Moon Bay rarely comes down to a single shingle. It’s usually the salt-air failure of flashing, or moss lifting the starter strip, or wind-driven rain finding a penetration angle that standard step-flashing was never designed to stop. Most leak repairs in Half Moon Bay run $495 to $1,450, with the high end reflecting situations where we must replace rotted fascia, decking, or multiple sections of flashing. The price is fixed before work begins, and it’s guaranteed in writing for 365 days.
Flashing and Valley Leak Repairs
Half Moon Bay’s horizontal, wind-driven rain pushes water under shingles at a different angle than a vertical downpour, and that’s where leaks around chimneys, skylights, and valley intersections start. We replace the failed flashing with stainless components, re-lay the surrounding shingles to a tighter overlap, and seal the transitions properly. If the leak returns within a year, the second visit is free.
Decking and Underlayment Repairs
When the marine layer keeps a roof damp for months, wood decking beneath the shingles rots even when the shingles look fine. We remove the failed section, install new decking to code, and lay an algae-resistant underlayment before reshingling. You’ll know from the written quote exactly what’s being replaced and why.
Trusted Brands We Service in Half Moon Bay
We install and repair shingle systems from GAF, CertainTeed, and Owens Corning, because those manufacturers produce architectural lines with proven wind ratings and coastal exposure performance. Since Half Moon Bay roofs live in salt air and fog, we keep stainless flashing, algae-resistant underlayment, and ridge vent components stocked locally so we aren’t waiting on a supply run from the other side of the hills. If your existing roof is GAF, CertainTeed, Owens Corning, or IKO, we can match the current shingle so the repaired section blends in. Call (743) 200-8347 and tell us what’s on your roof; we’ll bring the right material the first time.
Common Roof Repair Problems We See in Half Moon Bay Homes
- Galvanized flashing rusted through in under five years. The salt-laden air near the coast pits standard galvanized drip edge and flashing far faster than inland. We see it on homes from El Granada to the bluffs, where rusted metal lets water wick behind shingles and rot the fascia.
- Moss and lichen lifting starter strips. The marine layer keeps roofs damp for hundreds of days a year. Moss grows under the shingle edges, lifts the starters, and blocks drainage until water gets under the field.
- Wind-driven rain penetrating around chimneys and valleys. Winter storms off the Pacific push rain nearly sideways. Standard step-flashing and shingle-overlap tolerances simply aren’t designed for that angle, and leaks appear at penetrations and valley intersections.
- Rotted decking beneath visually intact shingles. Constant humidity means wood decking can fail even when the shingle above it looks fine. We often open a small repair and find the real problem is the decking, not the shingle.
Pricing for Roof Repair in Half Moon Bay, CA
Here’s what Half Moon Bay homeowners should expect. A simple shingle replacement run is $395 to $650. Flashing repair or replacement is $600 to $1,250 depending on the metal type (stainless or aluminum costs more than galvanized). Leak repairs involving decking replacement run $1,200 to $1,850, and valley rebuilds range $950 to $2,200. That’s our range for this market, and you’ll have your exact number in writing before any work starts. What affects the price: the condition of the decking underneath, how much flashing is involved, and whether the roof is on an exposed bluff or a sheltered flat. The free estimate is exactly that: free, written, and yours to keep. Call (743) 200-8347 to schedule.
We Also Serve Cities Near Half Moon Bay
Our crews cover Roof Repair in Half Moon Bay and the surrounding coastal and bayside communities, including El Granada, Burlingame, Millbrae, and Belmont. If you’re just outside Half Moon Bay and dealing with a leak, a moss problem, or wind-damaged flashing, give us a call. The same written pricing, the same 365-Day Done Right Promise, and the same photo-badged technicians apply.
Serving Half Moon Bay, CA - Our Local Coverage Area
We’re based in the Half Moon Bay 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 Repair in Half Moon Bay
Yes. The California Building Code classifies Half Moon Bay’s open-coast exposure as a high wind-load zone, and repairs involving shingle replacement, decking, or flashing must meet the prescriptive fastening and overlap requirements for that zone. A compliant repair uses a nailing pattern rated for coastal wind speeds and a shingle system tested to those conditions, not the minimum used for inland roofs. We document the wind-rated nailing pattern on every repair so you have a record the work was done to the coastal standard. Call (743) 200-8347 to get a written quote that specifies the wind rating.
The marine layer sits over Half Moon Bay for hundreds of days a year, keeping roof surfaces near saturation point and feeding moss, lichen, and algae growth that roofs 15 miles inland never experience. That same dampness keeps the roof from drying between rain events and accelerates rot in the decking beneath the shingles. We remove the moss, replace any lifted or damaged shingles, and install an algae-resistant underlayment when we rebuild the section, so the repair resists re-colonization. Call (743) 200-8347 for a free estimate on moss removal and repair.
Stainless steel or aluminum, never standard galvanized. Galvanized flashing and drip edge on exposed coastal properties routinely rust through in 3 to 5 years, a failure that takes 20-plus years just a ridge inland. When we repair flashing in Half Moon Bay, the written quote specifies stainless or aluminum replacement, and that’s part of why our repairs hold here. Call (743) 200-8347 and ask for a written flashing repair quote that names the metal.
Yes. If you file a claim for storm or water damage, the insurer will ask what work was done, how it was fastened, and to what standard. A written quote that names the wind rating, the flashing metal, and the underlayment type gives the adjuster something concrete to evaluate, which can affect how the claim is paid and how your premium is renewed. We document every Half Moon Bay repair with photos and a written record of the materials and fastening pattern used. Call (743) 200-8347 for a documented written estimate.
It should name the flashing metal (stainless or aluminum, not galvanized), specify an algae-resistant underlayment, state the wind-rated fastening pattern, and include a written 365-day guarantee. A cheap quote will replace the shingles, reuse the old flashing, skip the underlayment entirely, and give you nothing in writing. That repair fails in a few years in Half Moon Bay’s salt air and fog, and you’ll pay twice. Our written quotes always name materials and include the guarantee. Call (743) 200-8347 and we’ll put it in writing before any work starts.
Written by Grant Whitlock, Owner at Mercer Roofing, serving Half Moon Bay since 2000 as part of the Threshold Group family of home-service companies.
If you’re in Half Moon Bay and need a roof repair that accounts for salt air, moss, and wind-driven rain, call (743) 200-8347. A live person answers, and your written estimate is free. The technician’s name and photo come to you before the visit. The price comes before the first nail.