Roof Systems

No membrane fails in the middle of the sheet first. Every roof system has its own weak habit: a seam that lets go at a T-joint, a lap that fishmouths at the end, a coating that peels where the primer was skipped. Choosing a system really means choosing which habit an owner would rather manage. Pasadena puts its own pressure on that choice, with a long dry summer that has reached 113 F in June, heat spells that turn up as late as October, and a rain season so short that slope and drains go untested until a February storm arrives. We install and repair the full range of low-slope and metal systems, and the first question is always what the building underneath can carry.

Single-Ply Sheets and Their Seams

A white TPO roof and a PVC roof are both heat-welded, which turns two sheets into one when the weld is made well. The trouble is at the corners, the pipe boots and the places where a technician had to hand-weld a patch around something awkward. EPDM relies on tape and adhesive at its splices instead, and those are checked at every T-joint. Where grease from a kitchen exhaust reaches the membrane, KEE roofing resists the oils that soften an ordinary sheet, which matters for the restaurants of the Playhouse District.

Asphalt Systems for Foot Traffic and Hard Use

Layered asphalt roofs earn their place where people and equipment are always walking. Modified bitumen is torched or mopped at the laps, and a slipped end lap is the first sign that a roof has begun to age. A built-up roof is more forgiving of rooftop traffic, and its base flashing plies at wall turns are where we put our attention when a repair is needed. Both systems suit roofs with plenty of curbs, hatches and mechanical paths, the sort of traffic an office building along South Lake Avenue can put on its roof.

Metal Panels, Foam and Coatings

A standing seam metal roof sheds water well, but it leaks at cut panels, clips and penetrations, so the sheet metal detailing has to be done by hand. A metal roof retrofit goes over an aging roof when the structure can carry the load. Spray foam adds insulation and seals complicated roofs, though its protective skin has to be kept whole. When the substrate is sound, silicone and acrylic coatings extend the life of a roof, and the choice between them often turns on how long water sits in low spots.

Reflectance, Fire Rating and the Specification

For a new low-slope nonresidential roof, or a qualifying alteration, the state energy code sets aged solar-reflectance and thermal-emittance values. Alteration scope is compared against the 50-percent and 2,000-square-foot thresholds, whichever is smaller. That rules out some dark membranes unless a coating or cap brings the value up. In the Very High fire hazard zones, which on Pasadena's map run through the Arroyo Seco, the area west and north of the 210 and upper Hastings Ranch, the roof must also reach a Class A rating as a whole assembly, deck and underlayment included, which narrows the choice again. Both rules are worked out before a system is named, not after.

Commercial Roofing Questions

How does an owner decide between a heat-welded sheet and a layered asphalt roof?

Foot traffic and the number of penetrations carry the most weight. A roof that is rarely visited and has a clean field suits a welded sheet well, while a roof crossed daily by service technicians usually rewards the extra layers of an asphalt system.

Can two different systems share one roof?

They can, provided the transition between them is detailed so that neither membrane is asked to bond to something it cannot. Additions built years apart on a large campus often end up with exactly this mix, and the joint between them gets the closest look.

How do I know if this roof can take a coating?

The existing membrane must be compatible, sound and dry. Adhesion tests and moisture checks should support the decision before coating is priced.

What belongs in a system comparison besides first cost?

Compare insulation, attachment, edge details, penetrations and future maintenance. A lower bid can move expense into upkeep or early replacement.

Bring us the drawings or the roof

Details decide whether a roof lasts, and the right system is the one whose weak points your building can watch. Have us look at yours before you settle on a membrane.