Metal roofing
Architectural shingles
Tile roofing
GAF
Owens Corning
Flat & low-slopeFree roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Roof Replacement in Monrovia: What It Costs and How We Work
A full roof replacement in Monrovia typically runs $12,500 to $28,000 for an average 1,800 to 2,400 square foot home, with architectural asphalt shingles landing between $550 and $750 per square (100 square feet). The foothill location pushes prices toward the upper end of that range when decking repairs, ice and water shield upgrades, and hillside access come into play. Seacrest Roofing handles everything from the first inspection to the final nail, and you can reach us at (855) 597-2817 for a free estimate.
What makes Monrovia different from Pasadena, Arcadia, or the flat basin cities is how the mountains shape every roof we touch. We work the foothill streets above Foothill Blvd and the older tracts near Old Town every month. Call (855) 597-2817 and we’ll walk your roof with you, tell you exactly what’s failing, and show you material options across seven shingle brands.
Why Seacrest Roofing Is Monrovia’s Roof Replacement Contractor of Choice
Monrovia homeowners tend to ask harder questions than most. A lot of these houses are 60 to 100 years old, and the owners know a wrong product choice on a south-facing slope means redoing the roof years early. That’s exactly the conversation we’re set up to have. Seacrest Roofing stocks and installs across seven manufacturers, GAF, CertainTeed, Owens Corning, IKO, Atlas, Tamko, and Boral. We’re not tied to one brand’s inventory or one manufacturer’s rebate schedule. We diagnose the roof first, then match the shingle to the slope, the exposure, and the budget.
Noel Chambers leads our team, and the way he runs a job reflects how Monrovia homeowners want to be treated. Written scope, written allowances, photos of anything we open up, and a price on every change before we proceed. Our Roof Replacement team works across Monrovia’s 91016 and 91017 zip codes, from the valley-floor tracts along Huntington Drive up into the canyon streets north of Hillcrest. When a homeowner near Old Town called us about a 1920s Craftsman with failing wood shingles, we opened the roof to find original 1×6 skip sheathing and no ice and water shield in the valleys. We replaced the decking with plywood, installed peel-and-stick shield in every valley and along the eaves, added new drip edge and ridge vent, then laid GAF Timberline architectural shingles. Every added cost was documented and approved in writing before we nailed a single shingle. That’s how we work in Monrovia.
Styles & brands we work with






Asphalt Shingle Roof Replacement in Monrovia
Asphalt shingle roof replacement is the bread-and-butter job for Monrovia’s mid-century tracts and the standard re-cover for older homes where the original wood shingles have aged past repair. Most Monrovia homes we quote fall between 1,500 and 2,600 square feet, with a full tear-off and architectural shingle install running $11,000 to $24,000 depending on pitch, layers, and how much decking needs replacing. A simple single-story ranch near Mayflower Village costs less than a steep two-story hillside home above Foothill, where every shingle bundle gets carried up a ladder or a crane.
Tear-Off vs. Re-Cover
Monrovia’s older homes sometimes still carry the original wood-shingle or low-slope built-up roof, and those get a full tear-off. We strip to the decking, check every sheet, and replace what’s rotted before laying new underlayment. Homes with a single layer of architectural shingles in decent shape can sometimes take a re-cover, but we’ll only recommend it if the decking and flashing pass inspection.
Ice and Water Shield in Foothill Valleys
Winter storms off the San Gabriels drive rain sideways, and that water finds valleys and chimney flashings fast. We install peel-and-stick ice and water shield in every valley, along all eaves, and at every penetration on Monrovia homes. It’s standard practice on our jobs, not an upgrade line item we spring on you later.
New Roof Installation in Monrovia
New roof installation in Monrovia usually means one of two things: a full replacement on a home that’s never been re-roofed, or a new roof on an addition, ADU, or hillside custom build. New construction on sloped foothill lots runs $16,000 to $35,000 for architectural shingles, and the cost swings hard on how much custom flashing, crickets, and underlayment the roofline requires. Irregular pitches and multiple valleys drive labor in a way flat valley-floor tracts never do.
Custom Hillside New Builds
Hillside lots above Foothill Blvd rarely have a simple gable roof. We see hips, intersecting valleys, dormers, skylight curbs, and chimney crickets. Material choice on these homes needs to account for wind uplift off the canyons and the deep shade cast by mature oak and pine canopy. We carry Tamko and Owens Corning lines that rate well for wind and offer enhanced warranty coverage when installed to manufacturer spec.
Roof Decking and Underlayment on Older Homes
When we tear off an older Monrovia roof, we often find skip sheathing or 1×6 boards with gaps. Modern shingle warranties assume solid plywood or OSB decking. We price decking replacement as a per-sheet allowance in our contract, so if rot or gaps show up, the cost is already set. You approve any additional sheet in writing before we install it.
Trusted Brands We Install in Monrovia
Seacrest Roofing carries seven shingle manufacturers, which means a Monrovia homeowner on a budget can look at IKO or Atlas, and a homeowner wanting a premium designer look can consider Owens Corning or Tamko lines with stronger warranty tiers. We keep common colors and materials available for quick starts on Monrovia jobs, and since we’re not locked into one brand, we’ll show you real trade-offs on cost, wind rating, and curb appeal. Your roof, your material choice. We just make sure it’s the right choice for the slope it’s going on.
Common Roof Replacement Problems We See in Monrovia Homes
- Skip sheathing under old wood shingles: Homes near Old Town built before the 1940s often have original 1×6 boards with gaps, not solid plywood. A replacement that skips new decking leaves shingles bridging unsupported spans, which voids most manufacturer warranties.
- Oak and pine litter in valleys and behind chimneys: On hillside streets north of Foothill Blvd, leaves and needles pile into valleys faster than anywhere on the valley floor. That material traps moisture, rots decking, and backs water up under shingles long before the top face of the roof shows wear.
- Uneven aging on south-facing slopes: A Monrovia roof can look fine from the street while the south-facing plane is years ahead of the north side. Sun exposure off the San Gabriel foothills bakes one side of the house while shade from the mountains and canopy keeps the other side damp and shaded.
- Undersized or corroded flashing on older chimneys and valleys: Wind-driven rain off the canyons targets flashing first. On older Monrovia homes we regularly find original galvanized flashing rusted through at the chimney base or valley intersections, and the leak shows up inside the house before any shingle looks bad.
See the difference
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AfterPricing for Roof Replacement in Monrovia, CA
Here’s what we quote on real Monrovia jobs. A standard single-story ranch with architectural shingles and a straightforward tear-off runs $12,000 to $18,000. A two-story hillside home with steep pitch, custom flashing, and decking replacement runs $20,000 to $32,000. Flat or low-slope roofs on older Spanish Colonial homes near Old Town fall between $14,000 and $26,000 depending on the system chosen. The big variables in Monrovia are deck condition, roof pitch, access for material delivery, and whether the home is in the foothills or on the valley floor. We write the decking and underlayment allowances into the contract up front, so you know the number before we open anything. Call (855) 597-2817 for a free estimate and a written line-item quote.
Roof Replacement Across Monrovia and Nearby Cities
We serve every Monrovia neighborhood, from the flats along Huntington Drive to the hill streets above Foothill, plus Mayflower Village, Duarte, Arcadia, and Sierra Madre. If you’re in any of these foothill communities and comparing roof replacement quotes, we’ll give you the same written scope and the same seven-brand material options we give our Monrovia customers.
Serving Monrovia, CA — Our Local Coverage Area
We’re based in the Monrovia 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 Monrovia
Yes, Monrovia requires a building permit for a roof replacement, and a tear-off on an older home can trigger current code requirements for decking spacing, underlayment type, and attic ventilation. The permit is part of our scope, not an extra you chase down. We pull it, schedule inspections, and close it out. When an older home’s decking or ventilation doesn’t meet current code, we write those upgrades into a written allowance before work starts. Call (855) 597-2817 and we’ll walk you through what your specific home will likely trigger.
We replace the valley metal or valley liner as a standard part of every Monrovia hillside job, not an optional add-on. Then we install wider valley metal where the debris load is heaviest and spec peel-and-stick shield under it. After installation, we recommend valley guards or regular seasonal clearing, because no shingle or valley system is maintenance-free under a mature oak canopy. We’ll show you photos of your valleys at the quote stage so you see exactly what’s collecting and how we’ll address it.
In most cases, yes. We can re-roof a single slope, but it has to be done carefully at the ridge and valley transitions, or you’ll create a mismatch and a future leak point. On steeper foothill homes, a partial replacement sometimes doesn’t pencil out because the labor to set up on one plane is close to what a full re-roof costs. We’ll give you both numbers and a straight recommendation on which way makes sense for your house. Call (855) 597-2817 and we’ll inspect the roof plane by plane.
For homes in the hillside streets above Foothill Blvd and in canyon-adjacent areas, we recommend shingles rated for at least 110 mph wind uplift, and 130 mph when the home sits in a direct canyon wind path. Most premium architectural lines from Owens Corning, Tamko, and GAF meet or exceed that rating when installed with the correct nail pattern and a full ice and water shield underlayment. The wind rating matters less than the install quality, which is why we spec the nailing pattern per the manufacturer’s high-wind instructions on every foothill job.
A roofing square is 100 square feet, and a typical Monrovia ranch runs 18 to 24 squares, while a two-story foothill home runs 28 to 40 squares. The square count matters because two contractors can quote the same house and one says 22 squares and the other says 27. That’s usually a measurement difference, not a material difference, and it changes the bottom line by thousands. We measure in person or via satellite, walk the roof when access allows, and show you the square count on your written quote so you’re comparing apples to apples. Call (855) 597-2817 for a free estimate with a measured square count.
Get Your Monrovia Roof Replacement Quote
We’ll inspect your roof, show you the real condition of every slope, and give you a written quote that includes material options across seven brands, decking and underlayment allowances, and a detailed scope of work. No pressure, no brand steering. Call (855) 597-2817 to schedule your free estimate. We work across all of Monrovia, Mayflower Village, Duarte, Arcadia, and Sierra Madre, and we’ll tell you exactly what your roof needs and what it doesn’t.
Written by Noel Chambers, Owner at Seacrest Roofing, serving Monrovia and the San Gabriel foothills.