Free roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Fast, Reliable Roof Installation Across Altadena
A full roof installation in Altadena typically runs $14,500 – $28,000 for a standard single-family composition shingle roof, with Class A fire-rated assemblies now required across the community’s Very High Fire Hazard Severity Zone. Most installations take 2 – 5 days once permits clear LA County plan-check. We know the terrain, the wind patterns off the San Gabriels, and the permit queue that’s been backing up since the Eaton Fire. Call (743) 200-8347 for a written estimate before any work starts.
Mercer Roofing has been part of the Threshold Group family since 2000, and our Altadena crews work directly with homeowners navigating the post-fire rebuild reality. When you call, a live person answers. When our technician arrives, they’ll already have badged in with a photo ID, and you’ll have their name and photo before they knock. That’s the Threshold Standard, and it’s how every job begins.
Why Mercer Roofing Is Altadena’s Preferred Roof Installation Company
Altadena homeowners are dealing with something no other community in Southern California is facing right now: a full-scale rebuild cycle running through LA County Building & Safety, not a city hall counter. We’ve installed roofs on post-fire new construction off Lake Avenue, re-roofed 1940s Craftsman bungalows near Farnsworth Park, and replaced builder-grade three-tab on 2010s tract houses by the Meadows. Each one required a different permit strategy, and each one cleared plan-check because we package the Class A assembly documentation the County demands the first time.
You won’t get a stranger at your door. Every Mercer technician is background-checked, identity-verified, and dispatched under the Threshold Verified standard. They arrive in a clean, marked uniform with a photo ID badge. Before the visit, you get their name and photo. It’s the most concrete thing we do to earn trust before a single nail is driven.
We write the price before work starts. Always. You’ll see the full scope, the material brands, the flashing details, and the warranty terms in writing. No change orders after we tear off the old roof and find soft decking. If we miss something in the estimate, that’s on us.
TPO Roofing Installation in Altadena
TPO Roofing Installation in Altadena is the standard choice for low-slope and flat roof sections on mid-century ranch homes, garage additions, and the growing number of ADU builds happening across the community. TPO (thermoplastic polyolefin) is a heat-welded single-ply membrane that reflects solar heat, which matters here where south-facing roof decks near the foothills bake harder than flatland Pasadena just below. A typical TPO installation on a Altadena garage or low-slope addition runs $8,500 – $15,000 depending on square footage, insulation board thickness, and edge detailing.
When TPO Makes Sense Here
Post-fire rebuilds with modern low-slope roof lines and original 1950s ranches with flat lanai roofs are the two most common TPO jobs we do in Altadena. The membrane’s reflectivity also helps keep second-story bedrooms cooler during the summer months when foothill sun loads the roof deck from mid-morning to late afternoon. We install TPO to manufacturer spec with reinforced seam welds at every penetration and termination bar at the edges.
Why We Use Reinforced Seam Details
Santa Ana winds off the San Gabriel front range lift membrane edges if the termination isn’t mechanically fastened and sealed correctly. We over-fasten the perimeter and add seam plates at stress points. That detail is written into every Altadena TPO scope we price.
Shingle Roof in Altadena
Shingle Roof in Altadena now means one thing: a Class A fire-rated assembly. The days of wood shake on a Craftsman bungalow near Altadena Drive are over under LA County’s Very High Fire Hazard Severity Zone rules. Composition shingles dominate the replacement market here because they’re affordable, fast to install, and meet the Class A designation when paired with the right underlayment and starter strip. A full architectural shingle installation on a typical Altadena home runs $14,500 – $24,000, with steep-pitch roof decks on Spanish Colonial Revival homes pushing toward the upper end.
What We Install on Most Altadena Homes
GAF Timberline HDZ and CertainTeed Landmark are the two most common lines we recommend. Both are Class A rated when installed as a complete system with the manufacturer’s underlayment, starter strip, and ridge cap. Owens Corning Duration is a solid third option for homeowners who want the widest color selection available locally.
Doing It Right Under the Current Code
On a builder-grade 2016 tract house off Fair Oaks Avenue near the Meadows, our crew tore off the original three-tab layer down to the decking, replaced two soft sheathing panels, and laid GAF Timberline HDZ architectural shingles over a full ice and water shield in the valleys with new drip edge, ridge vent, and pipe-boot flashing at every penetration so the roof still met the Very High Fire Hazard Severity Zone Class A assembly the County wanted. The homeowner kept the original fascia and soffit because they were sound, and we wrote the upgrade within their builder warranty’s approved-materials clause instead of voiding it. The install cleared County inspection on the first pass.
Trusted Brands We Service in Altadena
We install and repair roofs using manufacturer-recognized shingle brands: GAF, CertainTeed, Owens Corning, IKO, Atlas, Tamko, and Boral. For Altadena specifically, we keep GAF and CertainTeed architectural lines readily available through our local supply relationships, which means fewer delays when a homeowner wants a specific color match after a partial tear-off or HOA design review. Owens Corning is the third brand we pull for Altadena jobs because their duration line holds up well under the granule loss we see from hot south-facing decks. Every manufacturer warranty is registered in the homeowner’s name at completion, and our written workmanship guarantee rides alongside it.
Common Roof Installation Problems We See in Altadena Homes
- Granule loss on builder-grade three-tab shingles. The original roofs on many 2005 – 2019 tract houses near the Meadows and off Fair Oaks Avenue were installed with minimum-spec three-tab that sheds granules within a decade under Altadena’s foothill sun. Homeowners notice granules in gutters and a thinning roof deck, and the fix is a full replacement with architectural Class A shingles, not another patch job.
- Permit sets rejected for missing Class A documentation. LA County DPW plan-check inside a Very High Fire Hazard Severity Zone requires the full assembly spec: underlayment type, starter strip, ridge cap, and the specific shingle’s fire rating. Submitting without that documentation sends the job to the back of a historic post-Eaton-Fire queue. We package it correctly the first time.
- HOA and architectural-review flags on visible material changes. Newer Altadena developments with CC&Rs require design approval before you swap shingle color, profile, or visible metal flashing. We’ve seen homeowners install first and ask later, then pay to redo the roof. We pull the HOA checklist before we order materials.
- Wind-driven underlayment failure at eaves and ridges. Santa Ana winds channeled off the San Gabriel foothills load the roof edges harder than the center field. Builder-grade starter strip and cheap underlayment tear at the eaves, letting water into the fascia and soffit. We upgrade both on every Altadena installation.
Pricing for Roof Installation in Altadena, CA
Here are honest ranges for what we’re installing in Altadena right now. A full architectural shingle roof on a 1,800 – 2,400 sq ft single-story ranch runs $14,500 – $20,000. Two-story Craftsman and Spanish Colonial Revival homes with steeper pitches run $18,000 – $28,000. TPO on a low-slope garage or ADU runs $8,500 – $15,000. What moves the number: roof deck square footage, tear-off layers, sheathing replacement if water damage is found, pitch, and the specific Class A assembly the County plan-check requires for your lot’s fire zone designation. Your estimate is written, itemized, and fixed before we start. Call (743) 200-8347 and we’ll schedule a free, no-pressure walkthrough.
We Also Serve Cities Near Altadena
Our crews serve the surrounding foothill communities: Pasadena, La Canada Flintridge, San Marino, and Sierra Madre. If you’re just over the line in any of those areas, you’re still getting the same Threshold Verified technicians, the same written pricing, and the same Roof Installation workmanship we bring to every Altadena job.
Serving Altadena, CA - Our Local Coverage Area
We’re based in the Altadena 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 Installation in Altadena
No, not if the installation uses materials and assemblies documented in the builder’s approved-materials clause. Most builder warranties for Altadena tract homes specify a set of manufacturer standards the work must meet. We pull that clause before we quote, and we write the scope to stay inside it. On the 2016 tract house near the Meadows, we kept the original fascia and soffit and matched the new GAF system to the builder’s approved list, so the warranty held. Always share your builder warranty packet with your roofer before they order anything. Call (743) 200-8347 if you want us to review yours before you commit to a bid.
Altadena is unincorporated, so there is no city hall to issue the permit. Every roof installation permit runs through LA County Building & Safety plan-check, and inside the Very High Fire Hazard Severity Zone, they want the full Class A assembly documentation: shingle fire rating, underlayment type, starter strip, ridge vent, and flashing details. The County is still processing a historic post-Eaton-Fire backlog, so a complete package submitted correctly the first time saves weeks or months. This is the single biggest reason to hire a roofer who already knows the County’s specific review checklist. Call (743) 200-8347 and we’ll walk you through what your permit will need.
Wood shake and non-fire-rated materials are no longer compliant inside LA County’s Very High Fire Hazard Severity Zone, which covers virtually all of Altadena. Allowed assemblies include Class A composition shingles, concrete tile, Class A metal, and fire-rated synthetic systems, each installed with the full underlayment and starter strip package the County plan-check requires. Class A composition is the most common choice we’re installing on post-Eaton-Fire rebuilds because it balances cost, weight, and code compliance. For an exact quote on your rebuild or replacement, call (743) 200-8347.
It’s common on original three-tab roofs in Altadena, especially on south- and west-facing decks that catch the full force of foothill sun and Santa Ana wind cycle after cycle. Granule loss means the shingle’s protective layer is eroding, and the asphalt beneath is now exposed to UV. At that stage, spot repair doesn’t fix the underlying problem. We replace the roof with an architectural Class A system built for this exact exposure, and we document everything for the warranty. Call (743) 200-8347 and we’ll inspect the deck and give you a written, honest assessment.
Put all bids side by side on four things: the specific Class A assembly documentation included in the permit package, the tear-off depth (to the decking or just a layover), the flashing details (drip edge, valley treatment, pipe boots), and whether the price is written and fixed before work starts. A low bid that omits the underlayment the County requires will get rejected at plan-check and cost you months in the queue. We write every scope to pass LA County the first time, and we put the price in writing before a nail is driven. For a free bid comparison walkthrough, call (743) 200-8347.
Written by Grant Whitlock, Owner at Mercer Roofing, serving Altadena since the Eaton Fire rebuild began.






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