Reduce Damage, Maintenance Costs by Waterproofing Concrete Structures
February, 2021
Scientists have proven that sunscreen protects our bodies from UV radiation, sunburns and skin cancer. We accept that this invisible protection is important for our body, but for some reason, parking garage owners often don’t attach the same level of importance to protecting their investment in parking decks.
I have been protecting and waterproofing concrete structures for over 17 years. Most of my work involves talking to parking owners, property and facility managers, and maintenance teams around the world about the best ways to improve the durability of their parking structures and reduce their maintenance costs. My job is to explain to these clients the advantages of protecting their parking structures - it is the “wear sunscreen” equivalent for parking decks.
More recently, as a waterproofing manufacturer, I was shocked to find out that our number one challenge was NOT another product, system or company … it was that owners weren’t waterproofing or protecting their concrete structures at all. We were in fact, fighting against a lack of information. We were competing against something that requires zero budget, zero installation days, and zero preparation. However, owners making these types of short-term decisions end up having to deal with the long-term consequences of those decisions.
There is a common misunderstanding that waterproofing and maintenance of concrete parking structures is an option, rather than a necessity.
There is a common misunderstanding that waterproofing and maintenance of concrete parking structures is an option, rather than a necessity. In far too many cases, owners are choosing to do little or nothing to protect their sizable investment in these structures, believing that because it’s made out of concrete it will just last a long time.
Unfortunately, taking this path increases the likelihood these owners will experience sizable financial pain in the form of: structural damage repairs, increased maintenance costs, and disruption of business while the issues are fixed. This is in addition to having to ultimately pay to waterproof the parking structure anyway. It is the epitome of the phrase ‘pay me now, or pay me later’.
In my experience, owners can benefit from learning about the wide variety of materials that are available, as well as the varying levels of protection they each provide. In addition to that, understanding these factors will help owners make decisions about the short and long-term benefits of each product.
Parking Deck Deterioration
Water is one of the main contributors to parking deck deterioration. Moisture can start reactions between certain aggregates and alkali hydroxides already present in the concrete, creating a cycle of expansion and cracking, which leads to further moisture intrusion. Alkali-silica reaction is difficult to stop once it has begun.
Carbonation is another form of deterioration that occurs when calcium carbonate forms in the cement paste. If water is also present, carbonic acid will be formed, which lowers the pH of the surrounding concrete. The result will be a weakening and breakdown of the passive layer of concrete surrounding the steel reinforcement. In the presence of oxygen and water, this will then lead to corrosion of the steel, which will ultimately fracture the concrete and cause structural damage.
Moisture, laden with chlorides from de-icing chemicals, can be carried into garages and ultimately penetrate into the concrete, corroding the steel reinforcement and damaging the concrete. This process accelerates in the presence of chlorides that are dissolved in water from sea water or salts used for de-icing traffic surfaces. This is sometimes also referred to as concrete cancer.
A Unique Solution to Consider:
An innovative technology that’s rapidly gaining momentum in the U.S. marketplace involves the use of a Biochemically Modified Silicate Gel. The most unique feature of these long-term waterproofing systems are their ability to not only seal existing cracks in structural concrete, but to also seal ‘future cracks’ that haven’t even occurred yet. The ability of the concrete matrix to continually heal itself provides waterproofing protection for the ‘design life’ of the structure. This modified silicate gel technology is well-proven in the field, having been used on projects in many countries around the world over the past 40+ years.
Most owners don’t have the luxury of shutting down portions of their parking structures for extended periods of time, so that waterproofing can be applied. One of the advantages of the spray-applied systems is the speed at which they are installed. This translates to less down-time.
With all of the different types of waterproofing products on the market today, it can be confusing to know which one will provide the right combination of superior long-term protection, good value for your money, and limited down time for application. Modified silicate gel systems check all of those boxes, especially when you consider life-cycle costing (what the waterproofing will cost over the entire lifespan of the structure). These systems do not affect the appearance or the ‘slip resistance’ of the concrete surface, and are capable of bridging cracks up to 2.0 mm wide.
Final Thoughts
Just like with sunscreen protecting your body, the most effective way to protect your concrete structures is to stop deterioration before it begins.
If you own a parking structure that’s not properly protected, you should consider looking into waterproofing systems right now. There are a number of different treatments available depending on the current condition of your parking structure. The first step should be to have an expert inspect the structure, and provide a professional evaluation. This will help navigate the array of available solutions. The right parking structure maintenance program should not only protect the deck today, but also anticipate the maintenance needs of the future. Every day you wait shortens the potential life span of your investment.
Mario Baggio is the CEO of Alchemco, a global manufacturer of waterproofing and protection products. TechCrete 2500 Waterproofing Agent was voted the Most Innovative Product for Concrete in 2020. Mario can be contacted by email at mario@alchemco.com
