Lic #1007864 · Santa Clara County · Envelope
Roofing Systems & Waterproofing
Composition, tile, and flat roofing systems with forensic leak diagnostics and full waterproofing.
Our home base — Silicon Valley's capital, where JMG delivers high-end residential remodels, custom ADUs, and commercial build-outs across every district.
JMG installs and repairs roofing systems built for California microclimates — from wind-rated composition shingles in the East Bay to clay tile estates in Saratoga and cool-roof flat systems on commercial corridors.
In San Jose and across Santa Clara County, JMG delivers roofing under California Contractor's License #1007864 — permitted, inspected, and personally overseen by owner Jerry Guinn. Our leak-detection protocols trace water intrusion to its source before we ever lift a shingle, saving owners from repeat repairs and interior damage.
San Jose projects run through the City's Permit Center and the SJplans online portal — and San Jose's pre-approved ADU plan program can shave weeks off a backyard-unit timeline. From Willow Glen and Cambrian ranch remodels to Almaden Valley estates and downtown tenant improvements, JMG manages submittals, plan-check corrections, and inspections end to end.
What's included in San Jose
Recent roofing work
The process in San Jose
Private Consultation
Walk the property with owner Jerry Guinn. Honest scope, realistic timeline, and a written line-item estimate — free.
Design & 3D Rendering
See the finished project in photorealistic 3D before a single wall comes down. Finishes get locked before demo day.
Permits, Handled
Plans, submittals, corrections, and city or county coordination under CA License #1007864. You sign — we run the process.
Build & Final Inspection
Sixteen in-house trades on one schedule, one accountable owner. Inspection passed, walkthrough done, keys in hand.
Roofing in San Jose — FAQ
Most composition-shingle re-roofs run three to five working days; tile and flat systems run longer. We tear off only what we can dry-in the same day — your home is never left open overnight.
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Roofing · San Jose