It wasn’t the solution the maintenance department at South El Monte High School found very effective at first. When random tiles in its cafeteria-um – an 11,344-square-foot multi-purpose room that houses a host of events, including varying lunch shifts – started popping up; the flooring started creating trip hazards. So department workers simply replaced the tiles. Unfortunately, it became a continual cycle of tile pop up, repeat, tile pop up, repeat.
It is the kind of issue Chris Kelly knows all too well. As the operations manager for Sunbelt Flooring in Chino, Calif., Kelly has seen the moisture-beneath-the-surface tiling issue cross his desk before.
Simply replacing the tiles – whether by the school’s maintenance crew or an outside contractor – was a solution that the administrators of the suburban LA high school knew had reached band-aid proportions.
Hitting that “enough-is-enough” moment, administrators knew the cafeteria-um floor had to be fixed once and for all, so they put the project up for public bid last fall.
That’s where the Sunbelt team entered the picture. Working with CJ Knowland, a project engineer for Construct 1 in Tustin, Calif., and Sunbelt’s field PM/install supervisor Fernando Madrid, Kelly assessed the damage. What they found was not surprising, at least not to them. After 15 to 20 years of cleaning the floor, the host of detergents and degreasers used by the various cleaning crews seeped into the joints of the VCT and soaked them, eventually creating a layer of contamination.
After testing the moisture vapor emissions rate (MVER) of the slab, they found that the existing concrete slab was reaching moisture levels upwards of 12 pounds per square foot (the ideal rate with impermeable flooring is 3 pounds per square foot). The next move was simple – Sunbelt Flooring, a company with more than 30 years of experience in the Southern California, had to remediate the moisture in order to install its proprietary Sunbelt 1100 Resinous Flooring System over the existing concrete substrate.
“Just looking at the flooring, you could tell there were numerous moisture issues,” Kelly says. “There was a lot of contamination that the moisture was pushing out of the slab. That was really a huge issue. It wasn’t dangerous or anything, but anytime you’re trying to get any kind of material to bond to concrete and moisture it is an issue. It is an absolute must that the moisture be treated to not affect the integrity of the material. In our case, we had to apply the Sunbelt 1100 system to it. Moisture is bonding’s worst enemy. Our industry (resinous flooring) is saturated with installers that do not test for moisture. Failure to do so gives our industry a bad name.”
The cafeteria-um featured vinyl composition tile (VCT) – an inexpensive flooring material used in retail and commercial buildings. The moisture kept pushing the VCT up, which caused the tiles to pop. The moisture created costly repairs and trip hazards, especially in one area, which Kelly mentioned looked like it had been repaired multiple times.
“I don’t think anybody knew that crack – as big as it was – was there,” Kelly says. “When you have a wide open structural crack this size, the moisture tends to take the path of least resistance and migrate to the closest opening. They were having a lot of issues over the top of that crack. There was so much glue packed down in there from all the times it had been repaired that it was hard to see. We were able to see it after we shot-blasted the floor.”
Sunbelt began preparing the floor by mechanical means – shot blasting, grinding, etc. For typical jobs, CSP 3 or 4 is needed. In this case, they used a CSP 5- to 6-blast that would all but guarantee the contaminants was cleaned off.
Next, they performed a water penetration test, which consisted of pouring a small amount of water onto the floor and timing how long it takes took to penetrate. “This helps assure that we are going to get the proper penetration rate for our materials,” Kelly says. “No concrete is the same, so this is actually a very important step that we take.”
Adding that final touch
To insure the slab would be free of moisture concerns, Sunbelt turned to AC Tech’s 2170 and 2170 FC, which features the company’s Go Early Technology. The products are 100-percent reactive solids, vapor reduction epoxy that have been tested to contain ZERO VOC emissions and almost no detectable odor, making it ideal for sensitive and soon-to-be-occupied areas.
Sunbelt saw cut and chipped the crack, removing all unsound concrete in the big structural crack, and then poured Fumed silica thickened AC Tech 2170 into the joints in the slab. They reinforced it with 2170 FC resin that was saturated into heavy mesh fiberglass. The 2170 and 2170 FC saturated in the woven fiberglass is used to displace the movement of the joints. Kelly says it is very important to use the 2170 to fill the joints and not a standard epoxy. “If you don’t fill the joints with the AC itself, the moisture will find the joint and push out the filler, thus causing a failure, since standard epoxy is not designed to withstand what this slab had in moisture.”
The product was just what the team needed to get the job done. “We were required to find a product that would provide protection with an existing concrete slab reaching the moisture levels that it had,” Knowland says. “The AC Tech product was able to provide that along with a 15-year warranty. It provided the solution to our moisture issues and the owner was very pleased with the end results.”
The job is the kind the whole team can put in the win column. “Sunbelt is as reputable and quality flooring contractor as you are going to find,” says Dawn R. Parnoff, executive VP, AC Tech. “They don’t cut corners. We trust them; which means we never have to worry about the application when they are on the job. It is the best-case scenario – the right company and right product equals success.”
In the end, South El Monte High School was able to get its cafeteria-um back without the constant need to keep replacing tiles. “There is a bit of sticker shock when you need to make an investment like this, so it was a hard pill to swallow for the school district,” Kelly says. “That’s why it is so important to use right product. It was a team effort.”