Hybrid Roof Hatch Solves Corrosion Dilemma

The Virginia Department of Transportation (VDOT) hazardous material storage building is used to store salt and de-icing products that are used on snowy and icy roadways. Problem is, the corrosive nature of salt can adversely affect nearly any building material. Some building materials, especially roofing components on the VDOT building, had deteriorated over time due to that corrosive impact.

As the building ages, the overall salt content of the building increases. The building fabric tends to become damper over time. When the salt dries out, it crystallizes and expands, causing crumbling, spalling, flaking and cracking of the building fabric, which happened at the VDOT building.

Architect Gauther Alvarado Assocs. developed a hybrid solution with BILCO roof hatches that is efficient and durable. The architect team specified three aluminum models, each 3 ft., 11-in. wide and 11-ft. long. The custom-made hatches include Type 316L stainless steel hardware, which is the most corrosion-resistant type of stainless steel. Salt is loaded at the facility through the roof hatches. This design saves time and labor, as it eliminates the need for salt to be moved via front-end loaders or some other means of conveyance.

As another layer of protection, the roof hatches include a liner, which is similar to the lining on truck beds. The spray-on material protects against corrosion while also providing abrasion, impact, and chemical resistance. The aluminum hatches with the liner were more cost efficient than stainless steel roof hatches. “With this solution, we combined the durability associated with the BILCO pre-manufactured aluminum roof hatches with the corrosion-resistant properties of the truck bed liner,” said Stephanie Stein, lead architect on the project for Gauther Alvarado.

Another critical design component are steel bumpers that support the roof hatch during loading operations. “The additional force applied to the roof hatch covers during the salt loading is then directly transferred to the steel bumpers to protect the structural integrity of the roof hatches,” Stein said.