Flat Roofing for the Mission's Flats, TICs, and Mixed-Use Buildings
A large share of the Mission District's housing — Victorian rear sections, small apartment buildings, live-work lofts — carries flat or low-slope roofing. We design and install TPO and modified bitumen systems that shed water and hold up under this neighborhood's direct sun exposure.
Where Flat Roofing Shows Up in the Mission
Flat and low-slope roofing is more common here than most owners realize, because of how the neighborhood's housing stock was actually built:
- Victorian & Edwardian rear sections — the flat roof behind the street-facing pitch on flats across the Mission, often owned as TICs with shared roof responsibility.
- Small apartment and walk-up buildings — nearly all flat or low-slope roofing.
- Live-work loft conversions — converted warehouse and industrial buildings, largely flat roofing.
- Mixed-use buildings — retail or restaurant space under flat-roofed residential units along Mission and Valencia St.
What a Flat Roof Install Includes
- Deck inspection and slope assessment to identify drainage paths.
- Membrane selection — TPO or modified bitumen — based on the structure, budget, and Title 24 compliance.
- Heat-welded or properly sealed seams built to handle direct sun and thermal cycling, not just occasional rain.
- Parapet cap flashing and drain detailing checked to eliminate the low spots that trap water.
Related Services
Flat roofing projects often connect to these services.
Commercial Roofing
Larger-scale low-slope systems for mixed-use and commercial buildings.
Learn more about Commercial RoofingGutter Installation
Drainage that works together with a properly sloped roof.
Learn more about Gutter InstallationRoof Replacement
Full replacement when a flat roof system has failed.
Learn more about Roof ReplacementWhat Is TPO Roofing, Exactly?
TPO — thermoplastic polyolefin — is a single-ply membrane installed in large sheets and heat-welded together at the seams into one continuous, waterproof surface. It's almost always white or light gray, which isn't just cosmetic: that reflectivity satisfies Title 24's cool-roof reflectance requirement for flat re-roofing, and it's a genuinely useful property in the Mission's above-average sun, bouncing summer heat back instead of absorbing it into the building below.
Installed cost typically runs $4–$10 per square foot on the lower end (up to $17 for thicker, higher-spec membranes), with a 20–30 year expected lifespan depending on membrane thickness and installation quality.
Read the Full Multi-Family Roofing Guide
We wrote a complete guide to flat roofing on the Mission's flats, TICs, and apartment buildings, covering signs of failure, TPO vs. modified bitumen, and what repair and replacement actually cost.
Read the GuideFlat Roofing Questions
Why is flat roofing so common in the Mission District?
The Mission's housing stock includes a large share of Victorian and Edwardian flats with a flat rear section, plus small walk-up apartment buildings, live-work loft conversions, and mixed-use buildings along Mission and Valencia St — nearly all of which are flat or low-slope roofing rather than a pitched residential roof.
What is the difference between TPO and modified bitumen?
TPO is a single-ply reflective membrane, heat-welded at the seams, generally lighter in color and more reflective. Modified bitumen is a multi-layer asphalt-based system, often torch- or heat-applied, and tends to hold up well on smaller or more detailed roof sections. We'll recommend one based on your structure and budget.
Does my flat roof need to meet Title 24 cool-roof requirements?
Yes. California's Title 24 requires cool-roof-rated materials for flat and low-slope re-roofing statewide, San Francisco included. Given the Mission's above-average sun exposure, a reflective cool-roof membrane here isn't just a code requirement — it can make a real difference in top-floor comfort and cooling costs.
I co-own a building as a TIC — how does a flat roof repair get decided?
Roof repair and replacement on a shared building is typically a joint expense among TIC co-owners. We provide one written estimate and documentation set that all owners can review together, which usually simplifies that decision.
Need a Flat Roof Installed or Repaired?
Free estimate, drainage designed correctly the first time. We serve the Mission District and all of San Francisco.