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Waiting is always the hardest part—but when you’re waiting for the adhesive to set on rubber or vinyl flooring in contract projects, those three to seven days aren’t only hard, they can be very costly to a project’s schedule.
It is also unnecessary, thanks to a new adhesive system for vinyl and rubber flooring.
“Three days’ wait minimum was the rule of thumb, and no rolling loads for up to a week,” is how project manager and interior designer Marie Lukaszeski describes one of the standard frustrations with installing vinyl or rubber flooring. “When the project is a major renovation of a working hospital, you just don’t have that kind of time. Everything needs to be on a fast track, no exceptions.”
Lukaszeski’s firm, Interior Design Solutions, recently completed a 180,000-square-foot renovation of Lafayette General Medical Center in Lafayette, La. The project involved gutting Floors 2 through 10 in two towers and working around the operations of the multi-pod intensive care unit, as well as patient rooms.
“We were working on three floors of a wing at a time, from the top down. There were 40 different phases of construction on this project,” says Lukaszeski.
After the project was about 10 percent complete, the flooring vendor and installer approached her with a new adhesive system that would significantly speed up installation. At that time, the product had been tested but wasn’t officially on the market.
“This was a spray-on adhesive, designed to replace the traditional adhesives that had to be trowelled on. They told me that it had no VOCs and no smell, which is great, but the real selling point was the ability to get right on the floor after installation,” she recalls.
“A hospital, of course, is full of rolling beds and carts, all of them heavy, but you can’t completely shut down an area like the ICU for a week, or even three days. And it’s hard to convince the other trades and staff to wait for the old adhesives to fully cure, which means you often just have to live with tracks and dimples in the floor.”
Those tracks and dimples occur where the trowelled-on adhesives have been displaced—squeezed out from under that part of the tile or sheet before they’ve had a chance to fully set—before curing. In too many projects, these issues were just considered to be a fact of life.
The switch to a spray-on adhesive helped keep the Lafayette General job on schedule. And certain other properties of the new adhesive system have resulted in an improved client experience as well.
spray vs. traditional adhesives
The new spray-on adhesive system was developed by a specialty adhesives manufacturer, who then approached a specific supplier of rubber and vinyl flooring for input and testing in commercial projects. The flooring manufacturer applied the adhesive to several substrates and then “heat aged” them in a 180°F oven for several weeks. This method accelerates the aging of the adhesive, allowing the manufacturer to extrapolate the length of time it could warranty a lasting bond.
That supplier then approached the flooring contractor for the Lafayette Hospital project, Cornerstone Commercial Flooring in Baton Rouge, La. Together, they worked with Lukaszeski and Lafayette General to ensure that the installation was a success.
Up until now, the commonly accepted adhesive systems—acrylic, epoxy or urethane—had to be trowelled onto the floor, with the installer working on his hands and knees. In order to have the right viscosity for trowelling, about 80 percent of the adhesive compound is made up of water and fillers; only 20 percent is adhesive.
By contrast, the spray-on system used in Lafayette General is 100 percent active adhesive. It works like a pressure-sensitive material, but has a very high lateral sheer strength. The tile doesn’t move once you put it down, which is why you can essentially walk on it right away. And because there's not nearly as much adhesive under the tile, it doesn’t displace.
It is also VOC-free, FloorScore approved and non-staining. The 22-ounce canisters are completely recyclable and the design allows for the complete use of the contents, so there is no waste. The contents of each can cover up to 170 square feet.
It should be noted that older spray-adhesive systems were delivered in large propane-style canisters equipped with expensive application wands. The delivery propellant was prone to freezing, so the wands also needed to be wrapped with heating elements; if the glue froze in the wand, it required replacement at a cost of several hundred dollars.
field tested at lafayette general
One characteristic of the spray adhesive that became immediately apparent during the Lafayette General project was its longer “open time”—the period within which the adhesive can create an effective bond with the flooring material—compared to traditional adhesives. This allows the installer to spread more adhesive at a time without worrying about it “dying”—losing its bonding ability.
Once sprayed on the substrate, the “open time” is two hours. Before applying the floor, the adhesive must dry until it feels “tacky” (15 to 20
minutes), with no transfer to your fingers when lightly touched. This minimum “tack time” increases in high humidity and low temperatures.
The main difference between the formulations for vinyl and rubber is the tackiness of the adhesive during the open time; rubber has different bonding characteristics, requiring a higher level of tack. The rubber formulation is also designed to dry differently.
The high lateral sheer strength of the spray adhesive keeps the tiles or sheets in place during installation, which means that the installer can work directly from the floor he’s just installed, pulling additional pieces toward him—which some installation experts say results in tighter seams and a faster pace. With a traditional adhesive, the installer is pushing pieces together while kneeling on the raw substrate.
One of the biggest differences in laying a floor with spray-on adhesives is that the flooring tiles or sheets are held firmly in place while the adhesive sets. Because traditional trowelled adhesives remain soft during the curing process, the flooring and the adhesive itself may move until the curing period is complete, from three days to a week.
Using spray adhesives allows the installer to release the floor immediately for the other trades or for initial maintenance. Workers can use the floor fully within hours, instead of days, and without fear of irreversible damage to the floor. This was always a punch-list issue, installers say; an electrician’s ladder, for instance, would leave permanent dimples in the floor by displacing the traditional adhesives.
getting installer buy-in
“We were a little leery at first.”
Ben Lowery, vice president of operations at Cornerstone Commercial Flooring, says adopting the spray adhesive after a project was already in process wasn’t a complete leap of faith, having been impressed by the testing data. But still:
“We were walking into a job requiring 130,000 square feet of rubber tile. We weren’t going to be troweling at all, and had never used a spray adhesive. There’s a comfort level in trowelling, because a trowel is like an extension of a flooring contractor’s arm. To tell us that we’re going to go in and install that much rubber tile with an adhesive we hadn’t used before, and subject it to heavy traffic and heavy concentrated loads, definitely caused us a little apprehension,” he admits.
“But honestly, the real proving point was seeing for ourselves how well this spray adhesive worked, seeing it in action. The best thing about it is you can use the floor immediately after installation,” Lowery says.
“A large part of this job was floor by floor and everything was on a fast track. We would get done with a room and immediately there would be people installing beds, headboards, equipment and millwork literally within an hour of laying the floor. The hospital was right behind us every step of the way.”
In a project like Lafayette General, neither the interior designer nor the flooring contractor have any control over the schedule. In fact, they are often asked to find ways to make up for unforeseen schedule delays.
“Even when a schedule has been set, it’s being compressed every day,” says Lowery. “All the other trades are compressed, and we’re expected to go in there and save the day. Had we not had this new spray adhesive on this job, if we had to wait the usual 72 hours before allowing anyone on the floor, there’s no way the schedule could be kept. We would have had a very unhappy client.
“The time for actually laying down the floor isn’t that much different than with trowelling, because installers are pros,” he adds. “There also isn’t much difference in the adhesive cost per square foot, although the spray adhesive is a little lower in cost. The biggest consideration is immediate access to the floor. Removing the minimum three-day wait for curing is a huge benefit.”
Another time savings realized with spray adhesive, Lowery says, is the easy cleanup.
“You literally just have to wipe off any overspray with soap and water, which takes care of a lot of the flooring-related punch list items. Acrylic, epoxy and urethane are much harder to clean up. It never fails: the punch list will always say something about the flooring glue being on the walls. We have shields we hold up to catch splashes, but it always gets through. With the old adhesives, we had to use Goof Off or oils that leave a residue and a bad smell, and even paint thinner or mineral spirits. Sometimes it takes some pretty serious stuff to get those old glues off of floor surfaces or millwork.”
no vocs a fit for healthcare
Lowery says the spray adhesive’s lack of VOCs was another big positive in the Lafayette General project.
“We didn’t have one complaint about the smell, which is very unusual in a job this size. We’re very conscious about this with our materials, especially in hospitals. So not getting any negative feedback was yet another boost in our comfort level with this method.”
“The lack of a smell is the other beauty of it,” says Lukaszeski. “In sensitive areas like the ICU, we would have had to build a containment wall to capture any offgassing of that chemical smell. This is an ideal adhesive to use in a functioning healthcare facility, where you’ve got ill people trying heal. The old adhesives would smell for at least a day, but time is relative to someone who’s sick. Even five minutes of a smell like that is too much—zero smell is perfect.”
A containment wall in an ICU corridor also creates a safety risk for patients because it constricts movement of medical personnel, Lukaszeski says.
“We couldn’t shut down the corridor that connects the three ICU pods, but we found that we could use the spray adhesive to install flooring in half the width of the 8-foot-wide corridor without having to close it off. And we could immediately open the newly installed areas to carts and beds and foot traffic without any fear of damage to the floor.
“I honestly don’t know how we would have done this part of the project at all with the old adhesives,” she adds.
“One of the big differences in the spray versus the trowel adhesives is floor preparation,” says Lowery. “Last-pass trowelling catches the last of the debris left over from prepping and sweeping, because the installer is right down at floor level. You’re standing when you apply the spray adhesive and you might not see those last foreign objects on the floor, so the floor prep must be perfect.
“We decided that a last pass with a damp mop was the best approach. Any left-over dust will reduce the bond of the spray adhesive, and of course any debris will telegraph.”
“The one issue we did have in learning to use the spray adhesive was getting the right coverage,” Lowery notes. “We were probably applying half too much adhesive, which didn’t result in any quality issues, just a waste of adhesive.”
fast-track installation, plus easy tile replacement
“Initially I was a little bit concerned about the spray adhesive’s performance over time,” says Lukaszeski, “but we’ve had no issues, no tiles popping up, nothing. When the punch list included some tiles that needed replacing, we learned that you apply the adhesive to the back of the new tile away from the floor to prevent overspray issues; you can’t hit the floor below a single open tile space without getting some overspray.”
Pulling up a tile installed with a spray adhesive is easier than a tile installed with traditional adhesives. It’s a bit tougher than a pressure-sensitive carpet tile, but it certainly doesn’t require a demolition machine, and you don’t have to scrape the old adhesive off the back, retrowel the spot or worry about height variations.
Spray adhesive is also more forgiving than trowelled adhesives when it comes to concrete substrates. Acrylic, for instance, won’t flash properly when applied over a nonporous slab and underneath a nonporous floor like rubber. Spray adhesive reacts the same over porous and nonporous concrete. It also works over metal and cementitious terrazzo, avoiding the need to chip it out.
“We’ve used the spray adhesive on a few jobs since the Lafayette General project wrapped up in October of 2011,” says Lukaszeski. “It’s a great solution any time you’re working in a tricky area. For instance, the sheet vinyl flooring in patient restrooms in another hospital were failing. We had a very small window of access, replacing the floors in the evening to be ready for patients the next morning. I recommended that we use the spray adhesive to install new vinyl floors and it worked perfectly.”
Suppliers of spray adhesives say that they are designed for any project or part of a project that needs to be returned immediately to service. A hospital is the perfect example, of course, but another common challenge is replacing the flooring in elevator cabs. Or retail stores. Or office buildings.
“This is a real solution for fast-track jobs,” says Lowery. “Come to think of it, we have very, very few jobs that are not on a fast track.”