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ROOF CONDENSATION [ A Costly Problem ]

Roof condensation damages are a phenomenon commonly seen in industrial tilt-up buildings where a radiant barrier (foil insulation) is installed beneath the roof's framing members, trapping the framing bays and not allowing for proper air ventilation.

Roof condensation is moisture that develops at the roof ceiling area and is trapped by foil insulation or other types of radiant barriers and, if left untreated, can destroy the entire roof structure! This problem can be a 50-cent or a 10-dollar per square foot problem, depending on how long it goes uncorrected. Certain types of tenant operations can exacerbate the problem as well.

Typically the first stage of condensation issues includes "oxidation" of the aluminum alloy sub-purlin hangers, and is evidenced by "white" markings on the hangers. Usually the smaller, sub-purlin members show signs of corrosion first, and are typically covered by foil.

The second stage or progression of condensation issues includes "rust" on the metal hangers that support the framing members and is evidenced by red/orange rust and streaks on the iron hangers. Black streaks can also be seen running down the side of the lumber below the foil. This is most often evidenced before the rusted or corroded hangers are spotted.

Saunders works with several engineers that specialize in solutions for this type of damage and can help create a plan to repair existing hardware or, if necessary, replace it with new hardware or ledgers, depending on the severity or extent of damages.

Typical repairs for roof condensation damage include:

  • Remove or vent the foil insulation (this will help prevent/slow the corrosion process and protect the roof system's structural integrity)
  • Scrape and paint the hangers showing signs of rust
  • Add/modify existing hangers that supports the purlins
  • Add/modify existing hangers that support the sub-purlins (ledgering)
  • In severe cases, remove and replace roof framing members as needed

Review the following photos of roof condensation damage; if you see these conditions in your building, it's a good idea to obtain a thorough inspection, as it could be the sign of a serious problem...


Seismic Retrofit

Strengthening buildings for improved earthquake resistance

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Roof Condensation

Thorough inspection and repair of moisture damaged hardware

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Structural Repairs

Fixing structural problems without disrupting your business

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