In some instances snow may be stored on the top level of a parking structure. Snow storage requires detailed storage guidelines with regard to storage pile location and maximum size and height. Failure to follow storage guidelines may result in overloading the structure. This could create a structural failure or potential collapse.
Consideration should also be given to obstruction of sight lines, loss of parking spaces, and the deleterious effects of concentrated salts and deicers.
When considering the equipment utilized in the snow removal procedure, whether snow moving equipment or snow melting equipment, the acceptable wheel loads must be approved by an engineer. Typically, parking structures are designed for 3000 lbs wheel loads and a maximum distributed equipment weight of 50 lbs per sq ft.
Do not use deicing chemicals for the first year of the structure to ensure the concrete has had adequate time to cure. Properly designed, air-entrained and cured concrete is required to provide a durable concrete surface.
Deicers must be chosen cautiously as their use can affect the structure’s efficiency, life safety and longevity. Never use Ammonium Nitrate, Ammonium Sulfate, Calcium Chloride or Sodium Chloride (rock salt). Sodium Acetate, Calcium Magnesium Acetate, Potassium Acetate and Prilled Urea can be acceptable deicing chemicals.
Snow Removal Best Practices
Prior to the snow and ice season, have personnel, equipment and deicing materials prepared, eliminate water-ponding areas on the deck, clean drains of debris and drain all water from water lines used for surface cleaning to prevent freezing and breakage.
Snow plow blades should not come in direct contact with expansion joints, deck membranes, or joint sealants. Blades should be kept a minimum of ½” above these materials. Blades should also not impact vertical offsets between adjacent deck surfaces. Plows must be equipped with well-maintained rubber blades to minimize impact damage.
Reduced equipment driving speed should be used at such changes in floor slopes as the ends of ramps, washes at the ends of double tees, and handicap ramps.
Impact forces caused by pushing equipment or snow into walls or spandrels should be avoided. Additionally, impact forces applied to deck surfaces caused by dumping snow into storage piles should be avoided.
Avoid storing snow directly over floor drains.
All hanging icicle formations and frozen chunks of snow or ice that have fallen from vehicles should be removed daily.
Even if deicers were not directly applied to the deck, wash down all levels of the deck immediately following the snow and ice season using a high water volume hose. This is necessary because vehicles also deposit deicing agents in the structure.
Review and revise the snow removal plan based on experience and new technology.