Modified Bitumen Roof Systems in Orlando, FL

APP modified bitumen uses an atactic polypropylene modifier that gives the bitumen a plastic-like quality — it is harder at ambient temperature than SBS and handles Florida's sustained UV and thermal exposure without the surface softening that can occur with SBS in extreme heat. Torch application creates a monolithic bond between plies. In Orlando's 90°F-plus summer conditions, APP's thermal stability is a meaningful advantage over SBS for top-layer application.

SBS modified bitumen uses a rubber-like styrene-butadiene-styrene modifier that makes the membrane more elastic at low temperatures. In Florida's thermal environment, SBS is typically specified as a base sheet under an APP cap, or in applications where the membrane will be covered by gravel or a reflective coating that limits surface temperature. Standalone SBS cap sheets are not the standard specification for exposed-surface Orlando commercial work.

Granule-surfaced cap sheets are standard for exposed modified bitumen in Orlando. Smooth cap sheets require coating for UV resistance and are not recommended as final exposed surfaces in Central Florida's UV environment. White or light-colored granule surfacing improves solar reflectance and can help

Many Downtown Orlando office and mixed-use buildings from the 1970s through the 1990s have original built-up roofing systems at or past end-of-life. When the BUR deck is sound and the insulation cores show acceptable moisture levels, modified bitumen recover is a viable path: the existing BUR system provides a stable base, and the new modified bitumen layers add a fresh waterproofing layer without the full demolition cost of a tear-off.

The honest scope for a BUR recover starts with moisture cores in representative locations — at least one per 2,000 square feet and more near drains and perimeter edges. If saturated insulation is found, the scope shifts to selective tear-off of wet areas and replacement before the new membrane is applied. In Orlando's high-rainfall environment, we find saturated insulation on more than half of the aging BUR buildings we inspect — the 54-inch annual rainfall, concentrated drain paths, and decades of minor leak events add up.

Drain conditions are critical on BUR recover projects. The existing drain configuration was designed for the original roof's drainage area. We verify drain capacity, check strainer condition, and assess whether the recover will change the effective drainage path before specifying the insulation taper. A recover that changes the drainage slope by even a quarter-inch per foot can move ponding from one area to another in ways that are not visible until the first heavy rainy-season storm.

Torch application requires hot-work permits in most commercial jurisdictions. The City of Orlando and Orange County Building Department both require hot-work permits for torch-applied roofing. In occupied buildings — particularly healthcare, hotel, and theme-park-adjacent properties — the facility's risk management team may impose additional hot-work protocols. We manage all permit and coordination requirements before production begins.

Multi-layer modified bitumen construction, properly attached to FBC wind-uplift requirements, performs well in hurricane-wind events. The base-sheet attachment pattern is the critical variable — FBC fastener density requirements for Orange County perimeter and corner zones are specific and must be confirmed at permit inspection. The granule-surfaced cap sheet provides ballistic resistance to wind-driven debris that a smooth-surface single-ply membrane does not.

Yes. A TPO recover over modified bitumen is a common path for Orlando buildings that want to transition to a reflective single-ply membrane at the end of their modified bitumen's service life. The modified bitumen surface needs to be sound, clean, and properly prepared — loose granules or open seams need repair before the TPO is installed. We document existing conditions and specify any pre-recover repairs as part of the scope.

Most manufacturer warranties for modified bitumen systems run 10-15 years for system warranties. NDL warranties are available from some manufacturers at 15-year terms with specific installation requirements. Modified bitumen is not a 20-year NDL system on par with commercial single-ply — if 20-year warranty is the priority, TPO or PVC is the better specification.

Our project managers will pull moisture cores, document drain and deck conditions, and produce a written scope — recover or replace — with FBC wind-uplift documentation and manufacturer warranty path.