Underground Parking Garages – Regular Maintenance Needed to Protect Against Damage

January 2016

Maintaining an underground parking garage requires more than an annual or semi-annual cleaning.

Underground parking garages have moisture protection systems which break down over time. Reinforced concrete parking structures can incur damage when their moisture protection systems break down. This allows water and salt into the structure. Corrosion, including rust, can result. Weakened structures may be unable to support the weight of a parking deck. The eventual result is structural integrity problems and the potential for collapse.

It can cost between $100 and $500 per parking stall per year to maintain an underground parking structure.

All parking structures require eventual replacement. Brian DeCarli is Operations Manager of Metro Jet Wash, a company specializing in the maintenance and cleaning of parking structures. He advises that proper parking garage maintenance can save money by extending the life of a parking structure and delaying the time until a complete replacement is necessary. This is done by minimizing deterioration of the parking structure which includes limiting exposure to moisture and salt. Consider the following measures to extend the life of parking structure waterproof systems and minimize deterioration of the parking structure:

Power Wash Parking Decks

Removes salt from the parking deck and minimizes absorption into the concrete.

Limit Use of Corrosive Salt Products

Sodium chloride, magnesium chloride and calcium chloride should be avoided when possible. Alternate products include sand, potassium acetate, urea or calcium magnesium acetate.

Flush and Clean Floor Drains and Drain Pipes

Salt and moisture are brought into a parking garage by vehicles. Cleaning out drains and pipes helps to remove salt. Repair or replace damaged/clogged drains.

Inspect Moisture Protection Systems Annually

Identify areas of standing water, where water is leaking through or where joint sealants may be failing. Repair damaged areas.


For more information on maintaining parking areas, see the Condo Archives – Condo Building Management, subheading Infrastructure.

For assistance identifying companies that specialize in maintaining parking structures, Condo Resource Guide can help. Look under