Case Study: San Francisco Mission District Flat Roof Restoration
20-Year Silicone Solution Saves Building from Messy, Full Roof Replacement
After: The completed silicone elastomeric coating provides a seamless, waterproof barrier for this Mission District residential building
Project Overview: Solving Years of Persistent Leaks in a San Francisco Residential Building
Sure Roofing was asked last summer to offer its recommendation for a roof solution for a large residential project in the Mission District of San Francisco, close to the General Hospital. The residents of the building, which was 15 years old, had been experiencing roof leaks for years, due to a variety of factors, and were looking for a comprehensive answer that would be economical and protect their homes for the long term.
After thorough inspection and testing, our San Francisco roofing specialists recommended a two-stage elastomeric silicone coating system – a solution that would address the root causes of the leaks while avoiding the disruption and expense of a complete roof replacement.
Challenge: Ending Years of Frustrating Leaks for Mission District Residents
The 15-year-old building had developed chronic leak problems that were affecting multiple units. San Francisco's unique climate conditions had accelerated the aging process of the original roofing materials, creating ongoing frustration for residents and potential structural concerns for the building itself.
Before: The existing roof showed significant weathering, deterioration, and signs of previous patching attempts.
Our Solution: A Comprehensive Silicone Elastomeric Coating System
Rather than subjecting residents to a disruptive, expensive, and environmentally wasteful full roof replacement, our team developed a specialized restoration approach that would:
Eliminate all leak sources through meticulous detail work
Create a seamless waterproof membrane across the entire roof surface
Extend roof life by decades at a fraction of replacement cost
Minimize disruption to building occupants during the process
Qualify for a 20-year NDL warranty for long-term protection
Detail: Roof joints and transitions required careful preparation before coating application.
The Sure Roofing Proven Flat Roof Restoration Process
1. Critical Test Patching to Verify Substrate Integrity
The process began with strategic test patches to ensure the existing roof had retained sufficient integrity to provide an adequate substrate for the new waterproof membrane. This critical assessment determines whether a coating system is viable or if full replacement is necessary.
As our team explains: "It's important when specifying this type of roof to determine this condition, because if the existing old roof membrane is too far along in its aging process, then it cannot hold a new layer, and the final job will be unsuccessful."
Only after confirming the substrate's viability through successful testing could we proceed with confidence that the new membrane would perform as promised.
2. Meticulous Inspection and Prep of All Roofing Details
"Like all large buildings, it's always the details that are the source of problems," notes our project manager. This essential step separates professional San Francisco roofing contractors from less experienced crews.
Our team meticulously inspected the entire roof area, identifying and addressing all potential failure points:
Trims and terminations where roofing materials end
Drains and water channeling systems critical to preventing ponding
Joints between roofing sections that can separate over time
Transitions where different roof planes meet
Penetrations for vents, HVAC, and other building systems
Each potential vulnerability was patched, repaired, or reinforced according to best practices for elastomeric coating systems. "This essential step makes the difference between a long-term waterproofing system and just another layer of material on a roof with problems," explains our head technician.
3. Thorough Surface Cleaning and Joint Sealing
The next phase for this Mission District project involved a complete cleaning of the flat roof area to remove dust, dirt, contaminants, and other accumulated materials.
"It's necessary to make certain that the new, fluid-applied roof coatings are being applied to the base roof, and not a loose layer on top. Without proper cleaning, any roof coating applied will not be allowed the opportunity to persevere," states our project documentation.
Following cleaning, our team carefully sealed all separated joints – an often-overlooked step that prevents moisture from building up beneath the coating. These moisture pockets can interfere with adhesion, leading to premature failure of the system.
