Flat & Low-Slope Roofing in Lake Tahoe
TPO, torch-down modified bitumen and Castagra coating systems for commercial buildings, additions and modern homes, with drainage designed for a roof that carries snow all winter.
What makes a flat roof hard in Tahoe?
Snow does not slide off a flat roof; it stays there until it melts, and it melts from the bottom. That means a low-slope roof in South Lake Tahoe spends months with standing meltwater under a snowpack, often refreezing every night. Any seam, any pinhole in a coating, any drain that clogs with needles becomes a leak. Structural load matters too: wet spring snow is heavy, and drains and scuppers need to keep up when a warm storm arrives on top of a deep pack. A flat roof here has to be watertight as a system, not just as a membrane, which is why drainage, tapered insulation and detailing get as much attention from us as the membrane itself.
Which flat roof system is right for my building?
For most commercial roofs and large residential decks we recommend a single-ply TPO membrane: heat-welded seams, a white reflective surface that handles summer sun, and good resistance to ponding water. Torch-down (modified bitumen) is a two-layer asphalt system with a granulated cap sheet; it is tough, handles foot traffic well, and is a common choice for smaller roofs, additions and roofs with a lot of penetrations. For a roof that is basically sound but aging, a fluid-applied Castagra coating can seal seams and add years of life without a tear-off. We inspect first, then recommend, because the right answer depends on the existing roof, the insulation under it, how the water leaves, and what the building is used for.
Drainage is the job
Every flat roof we install or restore gets a drainage plan. That may mean tapered insulation to create positive slope, new or enlarged scuppers and overflow scuppers, drain strainers that can be cleaned from the roof, and heat cable where a north-facing scupper freezes solid every year. Parapet caps, curb flashing at HVAC units, pipe boots and pitch pockets are all detailed to the membrane manufacturer's specifications so the warranty holds. We also walk the roof with you afterward and show you where to look after a big storm.
Commercial and residential
We work on retail and office buildings, restaurants, garages and multi-unit properties around the South Shore as well as residential flat roofs on additions, decks and contemporary homes. Commercial work is scheduled around your hours and, where the job allows, sectioned so the building stays open.
Flat roof systems we install
TPO single-ply membrane
Thermoplastic sheets with hot-air welded seams, mechanically fastened or fully adhered. Reflective white surface, strong seam integrity and good resistance to standing water.
Torch-down modified bitumen
Multi-ply asphalt membrane with a granulated cap sheet, heat-applied for a continuous bond. Durable under foot traffic and around many penetrations.
Castagra coatings
Fluid-applied, seamless coatings that restore a sound existing roof, seal seams and reflect heat. A cost-effective alternative to tear-off when the substrate allows.
Tapered insulation
Polyiso boards cut to create positive slope toward drains so meltwater leaves the roof instead of ponding.
Drainage hardware
Scuppers, overflow scuppers, internal drains and strainers sized for spring melt on top of a heavy pack.
Flashing and accessories
Manufacturer-matched curb flashing, pipe boots, pitch pockets, termination bars and parapet caps.
Signs your flat roof needs help
- Ponding water that lasts more than a day or two after melt
- Blisters, bubbles or open seams in the membrane
- Alligatoring or bare spots on an old coating
- Stains on interior ceilings below the roof, often near drains or units
- Scuppers or drains that freeze solid or clog with pine needles
- Sagging areas that suggest wet insulation underneath
- A roof coating that has never been renewed
How it works
Free inspection
We check the membrane, seams, flashings, drains and insulation, and note where water sits.
Written estimate
Restore vs. replace, the recommended system, and the drainage plan, priced in writing.
Install
Scheduled around your business; many roofs are completed in a few days.
Walk-through
We show you the drains, the details and what to watch after storms, and register the warranty.
From our recent work
Questions we hear most
Is TPO or torch down better for a Tahoe flat roof?
Both work when the drainage is right. TPO has welded seams and a reflective surface that suits larger commercial roofs; torch down is tougher underfoot and easier to detail around many penetrations. We recommend after inspecting the existing roof and how water leaves it.
Can you coat my flat roof instead of replacing it?
If the substrate is dry and sound, a Castagra coating can seal seams and add years of service for much less than a tear-off. If insulation is wet or seams have failed, a coating only hides the problem, and we will say so.
How much snow can a flat roof hold?
That is a structural question for your building's design, not the roof covering. What we control is getting meltwater off quickly through proper slope, scuppers and overflows so the load does not turn into ice and ponding.
Do you work on commercial buildings?
Yes. Retail, office, restaurant and multi-unit roofs around the South Shore, scheduled around your hours.
Ready for a roof that's built for Tahoe?
Get a free inspection and written estimate. Call (530) 314-1913 or send us a message.