Free roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
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AfterFast, Reliable Roof Installation Across Ontario
A new roof in Ontario, CA typically runs $9,800 – $18,500 for a standard asphalt shingle re-roof on a 1,500 – 2,200 sq ft home, with most projects completed in 2 – 5 days once materials land. The bigger variable here isn’t labor. It’s what we find when we tear off the old roof: rotted decking, failed flashing, and dry-rotted underlayment from decades of triple-digit heat. Mercer Roofing has worked on hundreds of Ontario homes, from Model Colony bungalows to the ranch tracts off Vineyard and Archibald. Our Roof Installation crews know this city’s housing stock, its wind patterns, and its permit process. Call (743) 200-8347 for a free estimate, always in writing, before any work starts.
Why Mercer Roofing Is Ontario’s Preferred Roof Installation Company
Ontario homeowners call us for one reason more than any other: they know who’s coming to the door before the truck pulls up. Every Mercer technician is background-checked, identity-verified, and arrives in a clean uniform with a photo ID badge. We send the technician’s name and photo ahead of the visit. That’s the Threshold Standard, and it’s non-negotiable on every job we run in Ontario.
We’re part of the Threshold Group family, founded in 2000. Each location is independently owned and operated, but every one is contractually held to the same verification and quality framework. When you choose a Roofing Company - Ontario from our family, that means your roof installer is vetted before they ever set foot on your property.
Grant Whitlock leads our team here. He’s built the Ontario operation around a simple rule: put every price, every guarantee, and every name in writing first. No exceptions. That’s why homeowners from the Creekside neighborhoods to the historic Euclid Avenue corridor keep our number saved. The 365-Day Done Right Promise backs every install: if it’s not right within a year, we make it right.
TPO Roofing Installation in Ontario
TPO Roofing Installation in Ontario is a common request for low-slope residential additions, patio covers, and a growing number of flat-roof sections on older ranch homes where traditional shingles simply won’t shed water properly. TPO, or thermoplastic polyolefin, is a heat-welded single-ply membrane that handles standing water far better than shingles on shallow pitches. In Ontario’s climate, it also reflects UV radiation instead of absorbing it, which matters enormously when summer days routinely cross 105°F.
A TPO installation on a typical Ontario residential flat section or addition runs $7,500 – $14,000 depending on square footage, insulation board, and decking condition. Homes near the airport corridor and the older ranch tracts south of the 10 freeway often have flat patio cover sections that are prime candidates.
Low-Slope Membrane Decisions
When a roof pitch drops below 2:12, shingles stop being a roof and start being a slow leak. TPO solves that with heat-welded seams that form a single, continuous surface. We see this constantly on 1950s – 1970s Ontario ranches where original built-up roofing has aged out and the geometry won’t support a shingle re-roof.
What TPO Installation Involves Here
We strip the old membrane or built-up layers, expose the decking, and inspect for rot before installing rigid insulation and mechanically fastening or fully adhering the TPO membrane. The heat-welded seams are tested for watertightness before we call the job done. Every TPO install includes our written 365-Day Done Right Promise.
Shingle Roof in Ontario
A Shingle Roof in Ontario is the most common residential installation we perform, and the math here is different than coastal LA. Asphalt shingles rated for 25 – 30 years are routinely failing at 15 – 20 in Ontario’s sustained heat. Granule loss, thermal cracking, and baked-out underlayment shorten the lifecycle significantly. Homeowners in neighborhoods like the Vintage Park and Amber Court subdivisions call us when their second or third shingle roof starts showing age well before the warranty expires.
A full shingle re-roof in Ontario typically runs $9,800 – $18,500. That range accounts for decking repairs, underlayment replacement, flashing, and the wind-rated fastening pattern this city needs. We work with GAF, CertainTeed, and Owens Corning in Ontario, among others, always installed to manufacturer spec with a written price before demo begins.
Wind-Rated Fastening for Santa Ana Season
Santa Ana winds funnel through the Cajon Pass and hit Ontario with gusts that lift improperly fastened shingles. The nailing pattern, not the shingle itself, earns the wind rating. We spec a six-nail pattern on most Ontario installs because the local exposure demands it, not because it’s an upsell.
Decking and Flashing Reality Checks
Older Ontario homes, especially the early-1960s ranch stock, often hide decking damage under a surface that looks acceptable. We write allowances for decking replacement and flashing repair into every Ontario contract, and any surprise is priced and approved in writing before we touch that square foot of roof.
Trusted Brands We Service in Ontario
We install and repair shingle systems from GAF, CertainTeed, Owens Corning, and IKO, and we stock common flashing components and underlayment locally for fast turnaround on Ontario jobs. When you call about a specific shingle line, you’ll speak with someone who knows its fastener requirements, wind rating, and how it performs under Inland Empire UV exposure. We don’t push one brand onto every roof. We match the product to the pitch, the exposure, and the homeowner’s budget, and we stand behind the installation with a written guarantee.
Common Roof Installation Problems We See in Ontario Homes
- Low-slope ranch ponding: The 1950s – 1970s tract homes across Ontario were built with shallow pitches and built-up roofing that has aged out. During atmospheric river events, standing water finds failed flashing and rotted decking long before anyone notices a ceiling stain.
- Heat-driven granule loss: Triple-digit summers bake the protective granules off asphalt shingles years ahead of schedule. Once granules go, the asphalt matrix underneath cracks and the roof’s service life collapses.
- Santa Ana wind lift: Hot, dry gusts through the mountain passes lift tiles and shingles that were nailed to a minimum pattern. Wind-rated fastening is a local necessity here, not an upgrade.
- Rotted decking surprises: On older Ontario ranches, especially around the Euclid Avenue corridor, the surface often looks fine while the 1×6 decking underneath has been quietly absorbing moisture for years. Opening the roof is the only way to find it, and finding it early saves thousands.
Pricing for Roof Installation in Ontario, CA
For a standard shingle re-roof on an Ontario home, expect $9,800 – $18,500. TPO flat sections run $7,500 – $14,000. What moves the number is decking condition, roof pitch, number of penetrations, and whether Santa Ana wind-rated fastening is required. Every Mercer Roofing quote includes a written allowance for decking and flashing repairs, and any additional work is priced and approved in writing before we proceed. You will never see a surprise on the invoice. Call (743) 200-8347 for a free, itemized estimate. The price we hand you is the price you pay.
We Also Serve Cities Near Ontario
Mercer Roofing serves homeowners throughout the western Inland Empire, including Montclair, Claremont, Upland, and Rancho Cucamonga. If you’re in a neighboring city and need Roof Installation work done right, we send the same background-checked, photo-badged technicians and the same written pricing to every job.
Serving Ontario, CA - Our Local Coverage Area
We’re based in the Ontario 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 Ontario
No. Shingles require a minimum slope, typically 2:12 or steeper, and Ontario’s 1950s – 1970s ranch homes often fall below that threshold. On a low-pitch roof you need a flat-membrane or modified bitumen system engineered for ponding water. Installing shingles on a pitch that’s too shallow will fail, often within a year or two, and manufacturers will deny the warranty. Call (743) 200-8347 and we’ll measure the pitch and tell you exactly what your roof can carry.
We write a decking and flashing allowance into every Ontario roof contract before we start. That means the contract assumes a certain square footage of rotted decking or failed flashing will need replacement at a set per-square-foot price, and we only charge you for what we actually find and replace, after you approve it in writing. No work proceeds on a surprise until you’ve signed off on the number.
Ontario’s inland valley position traps radiant heat and regularly produces sustained stretches above 105°F, consistently 10 – 15°F hotter than coastal LA. That heat bleaches granules, thermal-cracks asphalt, and dry-rots underlayment far faster. A shingle rated for 30 years on a coastal home is a 15 – 20 year roof in Ontario, which is why our replacement cycles and inspections run tighter here.
Yes. Santa Ana events funnel hot, dry gusts through the mountain passes directly into the western Inland Empire. Improperly fastened shingles and tiles lift, tear, or crack under those loads. The wind rating comes from the nailing pattern, not the shingle itself, and in Ontario we fasten to the higher standard by default because the wind exposure here is a known, recurring condition.
In Ontario, a roof replacement permit triggers inspection of the decking, underlayment, and fastening pattern. If the inspector finds rotted decking or non-compliant nailing, those items must be corrected before the roof is signed off. We handle the permit, schedule the inspection, and make sure every correction is priced and approved by you in writing before we do the additional work. You’ll pay what the contract says, not what the inspector’s list adds later.
Call Mercer Roofing for Your Ontario Roof Installation
You deserve to know who’s on your roof. You deserve a written price before any work starts, and a written guarantee that lasts a full year. Mercer Roofing delivers all of it to every Ontario homeowner we serve. Call (743) 200-8347 to schedule your free estimate. A live person answers, 24/7, and your written quote is the exact number on your final invoice.
Written by Grant Whitlock, Owner at Mercer Roofing, serving Ontario and the surrounding Inland Empire.