Reroofing Food Plants Without Disturbing the Line
Ready Pac Foods employs 1,900 people in the city, and the Huy Fong Foods sriracha factory cost about $40 million to build. A building that represents that much investment needs its roof replaced in a way that keeps the interior clean and the production running. We agree on a schedule with the plant manager, seal off openings at the end of each shift, and place equipment where dust and fumes will not reach intakes or open product lines.
The scope often includes the details that matter to a food plant specifically: sloped insulation so that water does not pool where cleaning crews walk, walkway pads along service routes and sealed penetrations that keep condensation, insects and debris out of the roof assembly. Where equipment sits close together, we lift or swing units with the building's technicians and rebuild curbs while the unit is clear of them.
Wide-Span Metal Roofs Over Large Interiors
Irwindale hosts motorsports at its Event Center and manufacturing in its plants, and wide-span metal roofs, where a building has them, bring demands of their own. A wide metal roof expands and contracts over a long run, and its fasteners, laps and sealant joints are the points where that movement is taken up. A panel that has worked loose will let rain in through the fastener hole, and a lap that has opened lets wind-driven water travel up the seam. We check each panel, replace fasteners with the correct type and reseal laps with compatible materials.
A standing seam metal roof deserves a particular kind of attention, since clips, seams and penetrations are all designed to allow thermal movement. We scan for restricted movement, sealant that has hardened at a penetration and corrosion at the edges. Where a retrofit makes sense, a metal retrofit over an existing roof can add life without a full tear-off, provided the structure is checked first.
Rain Loads and Heat Cycles on Flat Industrial Roofs
Pasadena, the market city, gets about 20.4 inches of rain a year. That is a Pasadena figure, not an Irwindale reading, but a very large roof sends a great deal of water to a few drains in any short storm. The heat has its turn too, with a recorded high of 113 F in June at Pasadena and a heat advisory near 100 F in October 2023, and that heat pulls on every seam and flashing.
The 2025 California Energy Code asks a roof that is new, or altered over more than half its area or 2,000 square feet, to meet the cool roof standard for low-slope buildings. We look at how that requirement fits with the drainage and insulation plan, so that a single design addresses both. When a reroof is urgent, our crews can respond to a failure at any hour through emergency roof repair and then plan the permanent work.
Records for Plants That Close, Sell or Change Operators
The Miller brewing plant was slated for closure by Molson Coors by September 2020, a reminder that large industrial buildings can close or change operators. When that happens, the incoming owner inherits the roof as it stands. A written commercial roof inspection establishes its condition, the extent of any wet insulation, the state of the drains and scuppers and the repairs worth making before the new operation starts.
For a larger owner, the same data feeds a roof asset management record that tracks each building over time. Where a business holds properties in Irwindale and in City of Industry or Azusa, each building is recorded in the same format, which makes it easier to decide which roof to repair this year and which to replace next.
Commercial Roofing Questions
What happens to a flat roof with tall parapets if the main drains clog?
It fills until the water reaches the overflow opening, if there is one. If there is not, or the opening is blocked, the water keeps rising and can load the structure and flow into the building through any weak flashing. Overflow scuppers are the last defense, so we test and clear them on every visit.
How can a food plant roof be replaced without contaminating the production floor?
By isolating the work from the interior and keeping debris out of the building's air. We seal penetrations temporarily, protect intakes, remove debris in covered chutes and keep the tear-off zone small. The plant manager sets the sanitation rules and we write them into the daily plan.
Is a retrofit over an old metal roof worth considering for a large shed?
It can be, if the existing panels and the structure will carry the new system and the fasteners still hold. A retrofit avoids the cost and disruption of tear-off, but it must be matched to the structure. We check purlin condition, panel profile and fastener pull-out before recommending it.
Who pays attention to the roof when a large plant sells?
Often nobody, until the first leak, which is why a buyer should order an inspection during due diligence. The report lists wet insulation, drain condition and likely repairs, with photographs, so the price negotiation reflects what the roof really needs.
Why do roof repairs on large industrial buildings so often recur in the same spot?
Because the repair addressed the leak and not the cause. A patch over a stain leaves a failed scupper, a pinhole in a seam or a loose fastener untouched. We trace each leak back to its source and fix that detail, then photograph the result so the next inspection has something to compare.
