Sometimes I scratch my head in complete confusion. I’ll have a number of very satisfied customers who’ve used a particular product and then I get the phone call from the Twilight Zone where the customer tells me how bad a product I sold him and how unhappy he is with the junk he got in the pail from us.

Case in point… we recently had a customer call because he was having a terrible blister problem when he used our Soft Tread Non Skid Coating. The phone call started to ruin my whole day so I had to summon my alter ego… Lieutenant Columbo (you remember Peter Falk with his cigar and overcoat, don’t you?).

I began the investigation by asking a ton of questions like; what was the substrate, how did you clean the surface, how long did you wait for the surface to dry, what was the weather like during this time, when did you apply the product, how did you apply the product, how soon was it before you noticed the blisters, were they air pockets or full of liquid, and on and on and on.

It wasn’t until I got a full load of answers that an answer to the problem began to arise from the depths of the dilemma.

The problem turned out to be quite common, water trapped under coating will cause blistering. The customer cleaned the surface (an exterior concrete deck) with a pressure washer. After blasting away with hundreds of gallons of water, the surface was nice and clean, but there’s a funny thing about concrete. The water soaks deeply into the concrete and the surrounding earth under the concrete gets good and wet also but the top 1/16th of an inch of concrete looks and even feels quite dry. So… you guessed it, they coated within a day or so of the cleaning process – right over the wet concrete under the thin layer of dry concrete.

Once the coating was applied, the moisture from within the concrete couldn’t get out and as the sun heated the coating, the moisture began to expand and POOF… blisters.

Well, it’s all simple in hindsight, but what can you do to prevent something like this happening with a concrete deck coating in the future? Do a MOISTURE TEST.

That’s right do a little test. Place a 3’ X 4’ piece of visqueen plastic onto the surface and weigh it down so the wind doesn’t blow under it or blow it away. Then wait a couple hours and remove the plastic. Can you see where the plastic was? If you can, what you’re noticing is the dampness that is under that thin surface layer that only seemed to be dry.

The customer wasn’t happy with the blisters, and if he had known to test first he would still be happy with our Soft Tread.

Just thought you might to know about this little test so you can head off a problem before it starts.