Soprema Modified Bitumen Roofing in Pasadena, CA

A modified bitumen roof from Soprema starts to leak at the side lap, the long seam where one cap sheet overlaps the next. Granules at the edge keep the bitumen from bonding, a lap that was walked on while soft stays slightly open, and the long line of an unfinished edge catches wind-driven rain on its way across the roof. Soprema, a French maker, produces Sopralene SBS and APP sheets for modified bitumen roofing, liquid-applied Alsan flashings and Sopra-ISO insulation. We install, repair and maintain these materials on Pasadena buildings, and we begin by studying the laps, the corners and the places where the sheet has to turn a hard edge.

Torch, Self-Adhered and Cold-Applied Methods

Soprema sheets can be installed by several methods, and the building decides which. Torch-applied sheets, such as the Sopralene Flam line, fuse to the base with an open flame, and they create a strong, even bond when a crew follows fire-watch rules. Self-adhered Stick sheets bond with a factory-applied adhesive, much like the self-adhering Liberty sheets from GAF, which makes them the usual answer next to a hospital air intake or any space where open flame is a concern. Cold-applied adhesive systems, using Soprema's Colphene products, sit between the two. Pasadena's fire hazard zones in the Arroyo Seco and upper Hastings Ranch call for special care with open flame in dry weather, and we choose the method that suits both the building and the season. Methods are spelled out in the scope before anyone lights a torch.

Brick Facades in Old Pasadena

Old Pasadena spans 22 blocks and more than 300 businesses, with historic brick-facade storefronts and offices on the upper floors. Where a roof behind one of those facades ends at a masonry parapet, the wall is where trouble starts. Brick moves with the seasons, mortar joints open, and water finds the open joint behind the flashing. We repair the masonry first, point the joints, then build the flashing with a cap sheet turned up the wall and finished in a reglet with a sheet metal counterflashing. The 1932 National Guard armory on North Raymond Avenue, now an arts center, is a reminder that old civic buildings in Old Pasadena deserve the same patient detail work.

Alsan Liquid Flashing at Awkward Details

Some roof details cannot be solved with a cut sheet: a cluster of pipes, a gutter outlet, a skylight curb with an odd corner. For these, Soprema makes Alsan liquid-applied flashing, a resin that is mixed on site, brushed or rolled around the detail and reinforced with fleece. It cures into a continuous membrane that bonds to metal, masonry and the roofing sheet around it. Preparation matters more than the resin. Surfaces are cleaned, primed and checked for moisture, and each coat is laid to a measured thickness. The result is a flashing that follows an irregular shape without joints. Skylight and penetration flashing on older buildings benefits from this method, as does any place where roofing meets old brick.

Mineral Cap Sheets and Class A Rules

A mineral-surfaced cap sheet gives a modified bitumen roof a hard, fire-resistant face. California Chapter 7A, which governs the Very High Fire Hazard Severity Zones, treats Class A as a rating of the whole assembly, and its detailing calls for a minimum 72-pound mineral-surfaced cap sheet in the underlayment and 36-inch metal valley flashing. In those zones, new buildings must have a Class A covering, and so must any roof that is more than half renewed within a single year. We check the listed assembly, the vents and the edges before ordering, and we plan the work for the dry season. In a city with a recorded June high of 113 F, the mineral surface also protects the bitumen from heat and UV damage.

Lap Walks, Granule Loss and Metal Edges

A modified bitumen roof ages in plain view if someone looks. Granules collect in the drains first, then bare patches of bitumen show along the lines where people walk. We make seasonal visits, clear the drains, press on every lap and inspect the metal edges for loose cleats. Built-up and modified roofs from Johns Manville age the same way, and the same walk applies to them. A short written report with photos follows each visit, and the report tells an owner whether a coating, a repair or a reroof is the next step. Watching for early granule loss lets us recommend a small fix while the sheet underneath is still sound.

Before selecting a liquid or sheet-applied system, we verify that the existing substrate is compatible and dry enough for the specified preparation. The crew records ambient and surface conditions, repairs pinholes and transitions, then checks the cured film or welded lap before accepting the work. At corners and drains, a reinforcement layer should carry beyond the change of plane so a thin spot does not become the first failure.

Commercial Roofing Questions

Can a modified bitumen roof be installed without an open flame on a restaurant in Old Pasadena?

Yes, self-adhered and cold-applied systems avoid torches entirely. Restaurants often have hood exhaust and fuel lines near the roof, so on a restaurant roof we favor those methods. We also coordinate with the kitchen and the landlord so that roof access and any shutdowns suit the dining schedule.

How do I tell whether a lap has failed on an older cap sheet?

Look for a lifted edge, a gap that shows the black bitumen underneath or granules gathered at the foot of a seam. A thin, bright line along a lap means the bond is gone. We probe suspect laps by hand, mark them and re-bond them with compatible adhesive.

Why would you use liquid flashing instead of a cut sheet around pipes?

Liquid flashing wraps irregular shapes without joints, which is the point where cut sheets fail first. A cluster of pipes or an odd corner leaves too many seams for a sheet to close well. Alsan resin flows around the shape and cures to a continuous skin.

Is a mineral-surfaced cap sheet enough to satisfy a fire-zone review?

A cap sheet is one part of the tested assembly. Chapter 7A looks at the deck, underlayment, insulation and covering together, and requires ember-resistant vents and gutter debris protection in the Very High zones. We confirm the full listing for the building before ordering any material.

What can an owner do to extend the life of a mod bit roof between visits?

Keep drains clear, keep traffic on walk pads and report any ponding after rain. Debris holds moisture against the surface and speeds wear. We pair those habits with a seasonal walk that checks laps, flashing and metal edges, then record what we find.

Have Us Look at the Laps and Parapets on Your Roof

Bring us the building and we will study the side laps, the masonry and the flashings before anyone quotes a cap sheet, because those details decide how long the roof stays dry. Call to arrange a visit, or call at any hour if water is already coming in.