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
Fast, Reliable Roof Replacement Across Monrovia
Roof replacement in Monrovia typically runs between $14,000 and $38,000 for a standard single-family home, depending on square footage, material grade, and how much decking needs to come out. That’s the honest range we quote most often here, and it reflects the real condition of Monrovia’s housing stock: a high-end architectural shingle roof on a newer foothills build sits at a different price point than a full tear-off and re-deck on a 1920s bungalow near Old Town. We’re Orange County Roofing Co, led by Kurt Hensley, and we’ve replaced enough roofs in Monrovia to know that the quote you get over the phone almost never survives first contact with what’s actually under the shingles. Call (866) 942-4187 and we’ll come out, get on the roof, and give you a written line-item estimate based on what’s actually there.
Why Orange County Roofing Co Is Monrovia’s Preferred Roof Replacement Company
Monrovia homeowners call us because we don’t arrive with one brand and a sales pitch to match. We carry seven major shingle lines, GAF, CertainTeed, Owens Corning, IKO, Atlas, Tamko, and Boral, so the conversation starts with what your home actually needs, not what earns the highest margin that week. That matters in a city where a mid-century ranch near Duarte Road wants something completely different from a foothills custom off Norumbega Drive.
Our inspection service is standalone. You can hire us to document exactly what your roof needs, with photos and measurements, and walk away with a report. No obligation to replace. No pressure. Homeowners in the 91016 and 91017 zip codes use that report to compare bids from other contractors, and many come back to us because the numbers line up with what we told them the first time. Our Roof Replacement team handles the full lifecycle: inspection, repair, and replacement under one crew, so you’re not juggling three different companies at three different stages of the roof’s life.
Kurt Hensley has built the company around a simple principle: the right product wins. When we recommend a Tamko or an Atlas over an Owens Corning, it’s because that material fits the home’s exposure, pitch, and budget, not because a rep bought us lunch. Monrovia’s older homes reward that kind of honesty, because they rarely reward shortcuts.
Styles & brands we work with






Reroofing in Monrovia
Reroofing in Monrovia usually means a complete tear-off down to the deck, and that’s a distinction worth understanding before you sign anything. A layover, putting new shingles over old ones, was common practice in the San Gabriel Valley for decades, but Monrovia’s building code now requires tear-offs in most situations, especially on the older homes near Old Town that already carry two or three layers. We quote reroofing jobs in Monrovia between $13,000 and $32,000, with the spread driven by decking condition, roof pitch, and whether the home sits north of Foothill Boulevard where fire-rated underlayment becomes non-negotiable.
When a Tear-Off Is Mandatory
Most Monrovia homes built before 1970 have at least one layer of original roofing under whatever was added later. Adding another layer compounds weight, masks decking rot, and voids most manufacturer warranties. Code requires a full tear-off when more than two layers exist, and we recommend it even when it’s technically allowed to go over. The extra cost up front almost always saves money within five years.
Decking and Underlayment in Older Homes
Skip-sheathing, the gapped plank decking common on 1910s and 1920s Monrovia homes, cannot hold modern shingles without a solid substrate. We replace it with rated plywood or OSB, then lay a full synthetic underlayment and ice and water shield through the valleys. In the foothills north of Hillcrest Boulevard, that shield is what stops the first hard Santa Ana rain from finding your living room.
Flat Roof Replacement in Monrovia
Flat roof replacement in Monrovia runs $11,000 to $24,000 for most residential applications, though a two-story flat section over a room addition on an early-1900s Craftsman off Myrtle Avenue can push toward $28,000 once we’re into decking and structural work. Monrovia’s mix of ranch additions, mid-century modern flat sections, and converted porches means we see flat roofs on homes that were never designed for them, and the details matter more than the material.
Built-Up and Modified Bitumen Systems
For low-slope roofs on older Monrovia homes, we lean on multi-ply modified bitumen systems. They handle our summer heat, where surface temperatures regularly exceed 140°F in July, better than single-ply membranes that can shrink and pull at the seams. The added weight also resists the wind uplift we get when Santa Anas channel down from the foothills.
Drainage and Ponding
Flat roofs in the 91016 zip code fail most often at the drains and scuppers, not in the field of the roof. We re-slope where framing allows, add crickets to break up ponding zones, and replace all penetration flashings as part of a standard flat roof job. A flat roof that holds water after 48 hours is a roof that will leak, and Monrovia’s late-fall rains will find it every time.
Trusted Brands We Service in Monrovia
Because we’re authorized installers for GAF, CertainTeed, Owens Corning, IKO, Atlas, Tamko, and Boral, we can match the warranty tier and the aesthetic to the home without bending the facts. A Craftsman near the Monrovia Historic District might want the dimensional profile of an IKO or certain CertainTeed lines. A 1950s ranch off Lemon Avenue might do better with an Atlas shingle designed for thermal cycling. We stock local material for Monrovia jobs through our Corona yard, which means no week-long waits for specialty trim, ridge vent, or ember-resistant components when a foothills job runs long. The right material for your roof, backed by the manufacturer’s own warranty, is the standard, not the upsell.
See the difference
Before
After
Before
After
Before
AfterCommon Roof Replacement Problems We See in Monrovia Homes
- Rotten skip-sheathing hidden under old layers. On early-1900s homes near Old Town, we routinely find gapped plank decking that has cupped, split, or rotted under decades of trapped moisture. A bid that assumed a simple shingle swap becomes a full decking replacement once the layers come off.
- Failed valley flashing and missing ice and water shield. Monrovia’s hillside lots direct water hard into valleys, and older roofs often lack any peel-and-stick membrane there. The first heavy Santa Ana-driven rain finds the interior before the shingles ever show wear.
- Ember intrusion through standard vents. Foothills homes north of Foothill Boulevard are in Wildland-Urban Interface terrain, and off-the-shelf soffit and gable vents do not stop wind-driven embers. Ember-resistant vents and Class A materials are not optional there; they’re the only thing between your attic and a wildfire front.
- Layered tar patches around chimneys and penetrations. We see chimneys near the base of the San Gabriels that have been tarred over for decades. When the roof comes off, the flashing and often the framing underneath are too far gone to salvage, and that work has to be priced and approved before we proceed.
Pricing for Roof Replacement in Monrovia, CA
Here’s what we quote most often in Monrovia. A full tear-off and architectural shingle replacement on a 1,400 to 1,800 square foot ranch or bungalow runs $14,000 to $22,000. Larger two-story homes and foothills custom builds run $24,000 to $38,000, with fire-rated underlayment and ember-resistant detailing adding $1,500 to $4,500 depending on the roofline’s complexity. Flat roof sections replace at $11 to $16 per square foot. The variables that move the number are decking condition, roof pitch and access, whether the home sits north of Foothill Boulevard, and how many layers are coming off. We give a written line-item quote so you see exactly where the money goes. Call (866) 942-4187 to schedule a free estimate, and you’ll have a firm number, not a ballpark.
We Also Serve Cities Near Monrovia
Our crew runs regular routes from Corona into the San Gabriel Valley, so we see homes in Monrovia alongside Mayflower Village, Duarte, Bradbury, and Arcadia. The housing stock changes block by block out here, from 1920s bungalows to 1970s tract homes, and the roofing details change with it. We schedule multiple jobs per route so Monrovia homeowners get on the calendar faster without paying a travel premium. If you live near the Duarte border or up against Bradbury, you’re still in our standard service area.
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
Most Old Town Monrovia homes already carry two or three layers of roofing, and current code requires a tear-off when more than two exist. Add to that the rot we find in original skip-sheathing decking on homes from the 1910s and 1920s, and a layover simply hides problems that will cost more to fix later. We recommend a full tear-off on nearly every pre-1950 Monrovia home we inspect. Call (866) 942-4187 and we’ll show you exactly what’s under your shingles before you commit to anything.
We write a decking allowance and a framing allowance into the contract before we start, based on what we see during inspection. If we open the roof and find additional rotten decking or framing damage, we stop, photograph it, price it in writing, and get your approval before we touch another shingle. You will never get a change order you did not see coming and did not approve first.
Yes, and more importantly it needs ember-resistant detailing at every penetration, because a vent that passes a Class A test in a lab still lets wind-driven embers through when the Santa Anas push a fire front through the Angeles National Forest toward your roofline. North of Foothill Boulevard, we spec Class A materials plus ember-resistant vents and flashing details as a standard, not an upgrade. Call (866) 942-4187 for a quote that accounts for your home’s elevation and exposure.
Put them side by side at the line-item level: what decking allowance was assumed, whether the underlayment is synthetic or felt, whether ice and water shield runs through the valleys, and whether the venting and ember detailing are actually specified. A lower bid that assumes no decking replacement on an older Monrovia home will climb once the roof comes off, while ours stays where we put it. We give you the line items up front because we want you to compare.
We install architectural and asphalt shingles from GAF, CertainTeed, Owens Corning, IKO, Atlas, Tamko, and Boral, plus modified bitumen systems for flat roofs. For Monrovia specifically, we steer foothills homes toward Class A fire-rated shingles with high wind ratings and ember-resistant underlayment, while flatland homes get more flexibility on aesthetics and budget. The material gets matched to your elevation and exposure, not to our supplier relationships.
Written by Kurt Hensley, Owner at Orange County Roofing Co, serving Monrovia and the San Gabriel Valley.