About us
California’s Authority in Home Diagnostics
Grandmark Roofing combines old-school craftsmanship with cutting-edge technology. While other contractors guess, our fleet uses X-Ray Diagnostics to pinpoint hidden leaks and AC failures that the naked eye misses. From Fresno to Sacramento, we deliver precision, not just repairs.
1,119+ Google Reviews
4.8
100%
100% Diagnostic Accuracy
Our X-Ray thermal technology finds the root cause of your leak or AC failure the first time, saving you money.
5,000+
Projects Completed
Protecting families across the Central Valley with honest, data-backed roofing repairs.
our Services
Your Roof Protected by Science
Grandmark is the only contractor in California using X-Ray Diagnostics to protect your home. Whether you need a simple repair or a full roof replacement, we don't guess—we verify every inch of your roof with thermal imaging to ensure the job is done right the first time.
Precision Roof Replacement
We install high-performance roofing systems designed to withstand California heat, backed by industry-leading warranties.
X-Ray Leak Detection
Stop chasing the same leak. Our thermal cameras find the exact source of hidden water intrusion so we can fix it permanently.
Annual Roof Health Exams
Don't wait for water to drip on your floor. Our diagnostic scans catch moisture under the shingles before it becomes a costly disaster.
Our Process
A Perfect Roof Starts With Facts
The X-Ray Inspection
We don't just guess. Before we quote, our technicians scan your entire roof with thermal imaging to pinpoint hidden moisture and structural rot that the naked eye misses.
The Transparent Quote
You get a detailed report with thermal photos showing exactly what needs fixing—no hidden fees, no surprise change orders.
Precision Installation
Our certified crews install your new roof using premium materials, backed by our Golden Pledge Warranty.
Reviews
See Why Neighbors Trust Grandmark
With 1,119+ 5-Star Reviews, we are the Central Valley's most trusted roofing team. We don't pressure you—we show you the X-Ray facts so you can make the right decision for your home.
Sarah J., Fresno
Homeowner
Paul Adler., Sacramento
Homeowner
Nick Pistoresi., Visalia
Homeowner
OUR PORTFOLIO
Real Results. Real Protection.
Browse our gallery of recent roof replacements and leak repairs across the Central Valley. Every project starts with an X-Ray diagnostic and ends with a roof built to last 30+ years.
Trusted By Top Companies:
Complete tear-off using High-Def Cool Shingles. Crucially, our X-Ray scan revealed hidden deck rot and a poor HVAC installation causing water ponding. We repaired the structure and corrected the AC unit before installing the new roof.
The concrete tiles looked perfect from the street, but our X-Ray diagnostics detected failing underlayment causing subtle leaks. We carefully lifted the existing tiles, installed a premium synthetic moisture barrier to waterproof the home, and reset the original tiles—saving the client thousands over a full replacement.
Latest blog
Roofing Insights & Expert Advice
The Grandmark Roofing System
We don't just nail down shingles. We install a complete, integrated protection system designed to withstand California’s heat and wind. Every roof is verified by X-Ray diagnostics to ensure no moisture is trapped underneath.
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130 MPH Wind Rating
High-performance shingles engineered to withstand severe storms and high winds.
Cool Roof Technology
Reflective granules reduce attic temperature, lowering your AC bills in the summer.
50-Year Warranty
Backed by the Golden Pledge — covering both materials and labor for decades.