Problem Solving Forum
November 3 - November 7, 2014
On a parking deck with harsh exposures—to road salt, frequent wetting, freeze-thaw cycles, and exterior weathering—what generic coating type works best, and why?
Darell Chamberlain of C. Darell & Assoc. Inc. on
November 14, 2014:
Exposure to the stated conditions and environment ...read more Exposure to the stated conditions and environment will greatly reduce the effective lifespan of the surface and internal structural integrity of the concrete slab. There are many criteria to consider when evaluating preventive measures; the first is effectiveness. The simple answer to effectiveness is not a coating, but an internal membrane provided by the appropriate penetrating silicate. I base this answer on 15 years of experience with engineers and many such structures, old and new, all over the world, which were in need of remedial or preventive solutions to exactly the conditions stated above. All coatings eventually fail, no matter the benefits they impart when new. Penetrating silicates, because they are in, not on, the concrete, are a structural component of the concrete, and therefore permanent. They will not fail unless the concrete to the depth treated is actually abraded away to expose untreated concrete.
The second criteria is cost. If an engineer is going to calculate the cost per square foot, per year of useable life, taking into the equation product cost, prep and application costs and maintenance costs, nothing comes close to penetrating silicates. The third criteria is environmental impact to the job site and the applicator, of coarse, but also the environmental impact of producing the product to be evaluated and disposing of it as well. The fourth criteria would be benefits imparted. A coating is a coating, although some types are better than others, and within the types, some brands are better than others. The same holds true for penetrating silicates--some are better than others, but where the real comparative advantages lie is in the benefits imparted. The damaging conditions stated in the case above eventually on their own will cause a coating to fail, as will any number of problems coming up from underneath the coating. With penetrating silicates there is no need for concerns about gases or moisture vapor coming up under your chosen penetrating silicate. The treated concrete is waterproof, 98% vapor proof, resistant to weak acids and salts, at least twice as hard, and this is permanent! So, when penetrating silicates are evaluated against coatings, criteria for criteria, they are far and away the best alternative for the job, the applicator, the environment, and the wallet of the structures owner. The above recommendation for lack of a better term is the "post-it note" answer to a question which deserves a more lengthy and site specific detailed answer, but in my experience is the best solution.