Free roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Before
After
Before
After
Before
AfterFast, Reliable Roof Installation Across San Dimas
Roof installation in San Dimas runs $14,000 – $38,000 for a typical 1,800 – 2,400 sq ft home, with tile re-roofs on the higher end and asphalt shingle work falling lower in that range. The number moves based on what we find when the old roof comes off, and in San Dimas specifically, a CAL FIRE Very High Fire Hazard Severity Zone designation can add WUI-mandated upgrades to any permit. We know this because we work these foothill neighborhoods every week, from the Via Verde custom homes to the 1970s tracts off San Dimas Avenue. Call (743) 200-8347 and we’ll walk you through what your specific roof actually needs, in writing, before anything gets nailed down.
Why Mercer Roofing Is San Dimas’s Preferred Roof Installation Company
San Dimas homeowners keep our number because we do something most roofers won’t: we give you a written price before work starts, and we honor it. On a 1970s tile ranch house off Via Verde, our crew pulled the concrete tile for an installation and found the original skip-sheathing decking was too uneven to receive new underlayment, so we re-decked, laid a rated fire-resistant underlayment, and set new ember-resistant vents to satisfy the county’s WUI requirements. The county inspector also flagged the open-soffit eaves, which we boxed and screened in the same permit cycle so the final sign-off wasn’t held up. That’s the kind of thing that turns a two-week job into a six-week one if your roofer didn’t plan for it. We did.
Every technician who steps onto your San Dimas property is background-checked, identity-verified, uniformed, and wearing a photo ID badge. Before they arrive, we send their name and photo to you. No stranger at the door, ever. Grant Whitlock leads our team, and he holds every crew member to the Threshold Verified standard, which each independently owned Mercer location is contractually bound to. A live person answers our phone 24/7, not a voicemail tree. When you call about roof installation in San Dimas, you reach a human who can actually help.
TPO Roofing Installation in San Dimas
TPO roofing installation in San Dimas typically runs $9 – $14 per square foot installed on low-slope sections, flat roof areas, and the occasional mid-century addition that has almost no pitch. TPO (thermoplastic polyolefin) is a white, heat-reflective single-ply membrane we heat-weld at the seams, which gives you a watertight surface that shrugs off the San Dimas summer sun better than dark asphalt materials. Homeowners on the flatter lots south of Bonita Avenue and around San Dimas High often have low-slope carport or patio roofs that need this treatment, and it holds up well against the kind of pooling water we see after Pacific storms squeeze extra rain out of the San Gabriels.
When A San Dimas Home Needs It
If your low-slope roof carries standing water after rain, or the old torch-down or built-up material is cracking and pulling at the edges, TPO is worth pricing. We see this on ranch homes with flat porch overhangs and on detached garage roofs across the older tracts near Foothill Boulevard.
What The Work Involves
We remove the old membrane, inspect the decking beneath, replace any rotted sections, and install the TPO with heat-welded seams rather than adhesives that fail in heat. San Dimas wind events off the canyons will test edges and flashings hard, so we mechanically fasten per manufacturer spec and never cut corners on perimeter detail.
Shingle Roof in San Dimas
A shingle roof in San Dimas costs $7 – $13 per square foot installed, which puts a full tear-off and replacement on a 2,000 sq ft home between $14,000 and $26,000 depending on shingle grade and whether we’re replacing decking. San Dimas has thousands of 1960s and 1970s ranch homes originally built with wood shake or early composition shingles, and many have been patched over the years rather than properly replaced. We install GAF, Atlas, and Tamko shingles, all of which carry strong wind warranties that matter here, where Santa Ana gusts off the San Gabriel canyons regularly push past 60 mph.
Shingle Selection That Works In Foothill Wind
Not every shingle handles sustained high wind the same way, and on north-facing San Dimas slopes where moss and algae collect, a heavier architectural shingle with a solid seal strip is the difference between a roof that holds and one that starts shedding caps after the first hard fall. We’ll talk through your exposure and pick a product rated for it.
What We Find Under The Old Roof
Most San Dimas homes built before 1980 have original 1×6 skip sheathing, not plywood. That’s fine under tile, but it often fails modern nailing requirements for shingles. We inspect spacing and condition, and if it’s too uneven or rotted, we re-deck before laying underlayment. It’s the kind of extra a cheap bid never includes, and it’s the kind that shows up on your invoice anyway if you picked the wrong roofer.
Trusted Brands We Service in San Dimas
We install and repair roofs using manufacturer-recognized shingle and tile brands including GAF, Atlas, Tamko, and Boral, which means we can usually match existing materials on San Dimas homes without a full tear-off. If you’re in a homeowner’s association near the San Dimas Golf Course or along Valley Center Drive and your HOA requires a specific shingle color or tile profile, we’ll source it and document compliance. For San Dimas customers, we order direct from local supply yards in the San Gabriel Valley, which keeps material lead times short, often under a week, even during the fall re-roof rush.
Common Roof Installation Problems We See in San Dimas Homes
- Permit-scope creep from WUI review. Once a San Dimas permit is issued for any roof work north of the 210 or along the Via Verde foothills, county inspectors can require ember-resistant ridge and soffit vents with 1/16-inch mesh, boxed and enclosed eaves, and a rated fire-resistant underlayment that was never in the original bid. We build for this from the first inspection so you’re not blindsided.
- Wind-driven cap and tile failure. Santa Ana wind sessions accelerate through the San Gabriel canyons and hit north San Dimas harder than flatland cities to the south. We regularly see popped hip-and-ridge caps and tile that has shifted because the original mortar bed cracked and let go.
- Failed underlayment under older tile. The slightly higher rainfall San Dimas gets compared to Covina or Pomona means old felt underlayment under tile roofs rots sooner, especially on north-facing planes that never fully dry. By the time we pull the tile, the felt underneath is often disintegrating.
- Framing issues at valleys and penetrations. Once old tile and felt come off, exposed framing around chimneys, skylights, and valley cuts often shows water damage or bad original construction. We repair and reinforce this before laying new materials, which is why our written quotes include a contingency allowance for framing repairs we can’t see until the roof is open.
Pricing for Roof Installation in San Dimas, CA
A full roof installation in San Dimas on an average 2,000 sq ft home lands between $14,000 and $38,000. Asphalt shingle roofs sit at the lower end, concrete or clay tile re-roofs run higher, and anything in the CAL FIRE VHFHSZ that requires WUI upgrades, boxed eaves, and ember-resistant vents will add $3,000 – $8,000 to the final scope. TPO on low-slope sections runs $9 – $14 per square foot. The honest truth: the price on your roof depends on what’s under the old material, and that’s why we inspect first and write any necessary change into a contract you approve before we proceed. Call (743) 200-8347 for a free estimate, and we’ll give you real numbers for your specific roof.
We Also Serve Cities Near San Dimas
Mercer Roofing handles Roof Installation across the eastern San Gabriel Valley, and our crews are in San Dimas every week. If you’re in La Verne, Glendora, Covina, or Azusa, you’re still in our service area, and you’ll get the same written pricing and badged technicians. You can also read more about Roof Installation in San Dimas right here on this page, or just call us at (743) 200-8347 and ask for Grant’s team.
Serving San Dimas, CA - Our Local Coverage Area
We’re based in the San Dimas 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 San Dimas
San Dimas sits in a CAL FIRE Very High Fire Hazard Severity Zone for much of its northern half, which means roofing permits here routinely trigger LA County Wildland-Urban Interface review, which adds required ember-resistant vents, boxed and screened eaves, and rated fire-resistant underlayment that flatland cities don’t demand. Steeper foothill pitches and tile-heavy housing stock also add labor. Call (743) 200-8347 and we’ll explain exactly what applies to your street.
Typically we find original skip-sheathing decking, rotted felt underlayment, and damaged flashing at valleys and penetrations, plus framing that needs reinforcement around chimneys and skylights. On WUI-permitted jobs, we also find that open-soffit eaves and standard box vents have to be upgraded before final inspection. We budget for this on the front end so the work doesn’t stall.
We walk the roof on pads and remove tile by hand in sections, stacking it in labeled piles so it can go back in place if only underlayment needs replacing. Concrete and clay tile from the 1960s through 1980s is brittle, and heavy foot traffic cracks it fast, so our crews use catwalks and distribution boards along the ridge and valleys. Call (743) 200-8347 and we’ll talk through your specific roof’s condition first.
Ask for a Class H or better asphalt shingle rated for at least 130 mph, and a tile roof installed to meet the county’s current wind-load requirements for Wildland-Urban Interface areas. Santa Ana events off the San Gabriel canyons regularly exceed 60 mph in north San Dimas, and we see cap and tile failures on roofs that were installed to older, lower standards. We’ll spec the right product and show you the manufacturer’s data before you approve.
Put both bids side by side and check three things: whether each includes WUI compliance if your home is in the VHFHSZ, whether decking replacement and framing repair are priced as allowances or will be billed as open-ended change orders, and whether each lists the exact underlayment product and vent type being installed. A lower bid that omits ember-resistant vents and boxed eaves isn’t lower; it’s incomplete. Call (743) 200-8347 and we’ll review any bid you’ve received, free.
Written by Grant Whitlock, Owner at Mercer Roofing, serving San Dimas since the company’s founding in 2000.