Selected Answers

From Michael Quaranta of OPERATIONS 40 on May 18, 2018:
Up to now, there are those good words on what to e ...read more Up to now, there are those good words on what to expect. That dried mastic needs some explaining, but it is wise to simply remove it so you can see what's underneath. I've been involved with a white label, water-based epoxy for more than 15 years that works wonders with a second identification known as a "liquid alloy." I'm in Southern California and would be pleased to provide additional information  to help you make the decisions.

From travis gold of Mid Atlantic Coatings on May 18, 2018:
You are correct in considering both options. The b ...read more You are correct in considering both options. The best decision will come from applying a test area of both. The coatings can provide protection from chemical attack, slip resistance and uniform appearance. The downside is periodic touch-up and eventual recoating. Polished floors will last much longer with only regular cleaning and periodic "buffing." Concerns with a polished floor are present. You will not significantly increase the chemical resistance. The slip resistance will not be improved (although it will be allowable under ADA standards). That being said, the major drawback to polished floors in a benign office or retail environment is the appearance. It is unpredictable. There is a high chance that you will see ghosting from the mastic unless you grind it very deep. This is more costly than a coated floor. The incorporation of stains will also help, but adds a layer of maintenance because they need to be reapplied periodically depending upon exposure. Long story made short, do a patch of each and see what you like! If there are chemical exposures of any kind, epoxy/urethane may be your best bet.

From Michael Krause of Veritox on May 16, 2018:
Check the mastic for asbestos; solvent removal or ...read more Check the mastic for asbestos; solvent removal or bead blasting might change your plan...

From Zenith Czora of Durotech Industries, Inc. on May 15, 2018:
The choice of concrete floor treatment should be b ...read more The choice of concrete floor treatment should be based on the desired performance, aesthetic and cost. The concrete floor treatment/coating, depending on the floor requirements and use, should provide provide abrasion-resistance, ease of cleaning, wear-resistance, resistance to thermal exposure, slip- resistance, chemical- and stain-resistance, ability to handle foot/vehicle traffic, ability to resurface, service life, low maintenance and low cost of replacement. Each floor coating system or treatments has its owns benefits and limitations.Select a concrete floor treatment or coating that will meet the demands and the desired aesthetic and mostly consider the requirement of use.Otherwise, for simple treatment, provided the substrates has been cleaned properly, you may polish the floor with a lithium-based concrete densifier and apply penetrating water- and stain-repellent.

From Michael Quaranta of OPERATIONS 40 on May 14, 2018:
When Costco polished the concrete floor in their l ...read more When Costco polished the concrete floor in their local store, it showed all of the dirt in the cracks. Best to prepare the existing concrete surface and remove the "fines." Also, it would be wise to avoid all solvent-based coatings.