Torch down roofing remains a trusted choice for flat and low-slope roofs across San Diego. This modified bitumen system uses heat to create a seamless waterproof membrane. For commercial buildings, garages, additions, and ADUs, torch down provides reliable protection when installed correctly.
Understanding Torch Down Systems
The name describes the installation method. Rolls of modified bitumen membrane are heated with a propane torch, melting the underside as the material is rolled onto the roof surface. This creates a bond stronger than adhesive or mechanical fastening alone.
Modified bitumen improves on traditional built-up roofing. The membrane incorporates plastic or rubber modifiers that add flexibility and durability. This flexibility matters in San Diego's climate, where temperature swings cause expansion and contraction throughout the day.
Two modifier types dominate the market. APP (atactic polypropylene) membranes handle heat and UV exposure well, making them popular in sunny climates like ours. SBS (styrene-butadiene-styrene) membranes offer better flexibility in cooler temperatures. Both work in San Diego, with APP being slightly more common.
The layered system provides redundant protection. A base sheet attaches to the roof deck. A cap sheet with granular surface goes over the base. Each layer adds waterproofing. Even if one layer is compromised, the other provides backup protection.
Why Choose Torch Down
Durability stands out among torch down benefits. Properly installed systems last 15 to 20 years with minimal maintenance. The heat-welded seams resist separation better than glued or mechanically fastened systems.
Weather resistance suits San Diego conditions. The reflective granular cap sheet reduces heat absorption during our warm months. The waterproof membrane handles our winter rains without issues. UV stability prevents the rapid deterioration some materials experience under our intense sun.
Foot traffic tolerance matters for roofs with HVAC equipment. Technicians servicing rooftop units need a surface that won't puncture or tear. Torch down membranes handle this traffic better than single-ply alternatives in most cases.
Repair simplicity extends system life. When damage does occur, patching torch down is straightforward. A professional heats the area, applies a compatible patch, and the repair blends seamlessly with the surrounding membrane.
Fire safety during installation requires experienced crews. The torching process involves open flame on your roof. Professional contractors understand safety protocols and carry appropriate insurance.
Installation Considerations
Contractor selection matters more with torch down than some other systems. The technique requires skill developed over many installations. Ask potential contractors specifically about their torch down experience and request references from similar projects.
Substrate condition affects results. The roof deck must be sound, dry, and properly prepared. Any soft spots, water damage, or deteriorated existing material needs addressing before new membrane goes down.
Vapor barriers may be necessary depending on building use. Structures generating high interior humidity need proper venting to prevent moisture accumulation beneath the membrane. Your contractor should evaluate this during the estimate process.
Permit requirements in San Diego include inspection at various stages. Reputable contractors handle permitting as part of their service. The inspection process ensures work meets building codes.
Maintenance extends torch down roof life significantly. Annual inspection catches any issues early. Debris removal prevents accumulation that traps moisture. Drain cleaning ensures proper water flow. These simple steps maximize your investment.
When comparing torch down to alternatives, consider your specific needs. TPO offers similar performance with a cooler surface but different installation requirements. PVC costs more but handles chemical exposure better. Built-up roofing has a longer track record but requires more maintenance. Torch down hits a sweet spot for many San Diego flat roof applications.
