Sheet Metal Along Huntington Drive and Foothill Boulevard
A commercial strip along a main thoroughfare has a lot of edge: parapets at the front, coping over party walls, gutters or scuppers at the back. Each joint in that metal is an expansion point, and in the long dry heat of a Southern California summer the metal works hard every afternoon. We form coping in manageable lengths, hem the edges, set cleats behind the lap and keep the sealant joint as a secondary seal and never the main defense. That is the difference between a cap that stays tight and one that opens every summer.
Where the roof meets a stucco or masonry wall, the counterflashing belongs in a reglet cut into the wall, not stuck to its face with a bead of sealant. We cut the reglet clean, set the counterflashing, and finish the corners by hand. This edge metal and coping work is slow and exact, and an owner sees the benefit as a ceiling that stays dry after the first big rain.
Wind, Embers and the Hazard Map
The Eaton Fire of January 2025 started in the foothills by Altadena and Pasadena and took 14,021 acres before containment, after forecasters had warned of Santa Ana gusts reaching 60 to 80 mph. On any roof, the edges, vents and rooftop units are the parts that meet wind and embers first, and any open seam or loose cap is where an ember finds its way in. Fire damage roof repair often starts at an edge for that reason.
Under the state's wildland-urban interface rules, a Very High Fire Hazard Severity Zone parcel needs a Class A roof covering on a new building and again whenever a reroof takes in more than half of an older roof within one year. Whatever the rating, it is earned by the full assembly of covering, underlayment and deck, not by the top sheet alone. Whether a given Monrovia parcel falls inside a mapped zone is a question for the current state map, and we check it at the address before a reroof is priced so that the owner is not surprised in permitting.
Reroofing Occupied Labs and Offices in Sections
Rooms with sensitive equipment or products do not tolerate dust, vibration or a drip. Before a tear-off starts on a building like that, we locate the sensitive areas, protect the interior side where it is needed and sequence the work so the area over those rooms is open for the shortest possible time. A moisture survey with infrared imaging tells us where the insulation is wet, so we remove only what has failed and do not pull up good material along with it.
Tie-ins are sealed at the end of every working day, and staging areas are placed away from entrances and loading points. On blocks near the Metro A Line station at Myrtle Avenue and Duarte Road, open since 2016, we keep walkways clear and set material drop zones where the public does not pass beneath a crane.
Condition Reports for Headquarters and Big-Box Owners
An owner with a headquarters building, a home-improvement store or a row of leased units needs a clear picture of every roof's remaining life. We provide that with a written roof condition report: photographs of each detail, a rating of what is sound and what is moving, and a priority list of repairs, so a capital budget is built from facts and not from guesses.
California’s cool-roof requirements use aged reflectance and emittance values, or an SRI alternative, for new low-slope nonresidential roofs and qualifying alterations. During a Monrovia project, we compare the measured work scope with the code trigger, then confirm that the selected product’s published test data meet the applicable values. Owners with buildings in several towns can extend the same report to Duarte and Azusa.
Commercial Roofing Questions
Why does a roof with new rooftop units still leak around them?
Because the units are installed on curbs and the flashing at the corners is the weakest part of the job. A short lap, a cut that was left open or a screw through the counterflashing lets water in at the first heavy rain. We rebuild the corner with wrapped or welded flashing and check that the curb is sloped so water drains off it.
How do we find out whether a Monrovia building needs a Class A roof?
Start with the address and the current state fire hazard severity map, which shows whether the parcel sits in a Very High zone. If it does, a new roof or a replacement of more than half of the existing one needs a Class A assembly with ember-resistant vents. We pull the map during the survey and confirm before pricing, not after permit review.
What makes reroofing a building with laboratories more expensive than a plain office?
Protection, sequencing and equipment. Sensitive rooms need interior protection, tie-ins are sealed daily, and units may need to be disconnected or lifted by the building's own technicians. Those hours are added to the roof scope, and they are listed separately in the proposal so the owner can see what the roof costs and what the protection costs.
Can a coping joint be repaired without replacing the whole parapet cap?
Often yes, provided the cap itself is still sound and the failure is confined to the joint and its cleats. We lift the cap, rebuild the lap, replace worn cleats and reseal. Where the metal itself has cracked at the folds or the wall behind it is crumbling, a new cap is cheaper than a repair that returns in a year, and we say so after looking at it.
Is a Foothill Boulevard retail roof treated differently from one on Huntington Drive?
Not by street name, but by construction. A long strip with shared walls has more parapet and more tie-ins than a freestanding building, so more of the cost sits in sheet metal and flashing than in membrane. We walk the roof, count the linear feet of edge and price the metal as its own line.
