Adhesive manufacturers don't set out to purposely engineer glue that does not work, contrary to what you may have heard. Exstensive testing is done to insure that the window of application performs in a variety of job site conditions. But as we all know, every job site is different, and you encounter different obstacles that you must overcome to ensure that an installation will perform well. There are times when the same floor covering is installed in the same building (in different areas) where one area has no problems but another has several.
What you see in the following photographs is a case in point where two different areas had two very different problems. Photos 1 and 2 are of one area, where reportedly the adhesive was oozing up between the VCT tile and the tiles were moving (tile slippage). Now this is not just a little oozing but rather a lot, as seen in Photo 2.
. But in another area (Photos 3 and 4) there is no oozing and the tiles are not adhering to the subfloor, as they should. Do the photos give enough information?
You Make the Call!
I should tell you that both of these conditions were apparent within days of the installation. Photo 5 is the area of oozing where a tile is in the process of being removed. As seen in Photo 6 of this area, the adhesive has no trowel ridges and does not appear to be dried. Quite the opposite, the adhesive is very wet! Photo 7 is a close-up of the oozing glue. Now what could have caused this condition? A flood? Improper open time? Or just bad adhesive?
If you allow this type (VCT) adhesive to cure properly, only a flood (maybe) would reactivate the dried adhesive film to the wet state such as you see in this photo. But for this to happen to this degree you would need a boat to access the job site and this entire job site was on a suspended wood (joist) second story building. But what else do you see? Tile over tile in this area of the installation, unlike the tile in Photos 3 and 4 which are over an OSB subfloor. Tile over tile requires almost twice the cure time as a wood substrate due to the lack of porosity in the subfloor. Also understand that the first (existing) tile must be stripped of all wax, grease and all contaminates prior to the installation of the new tile as this too would negatively effect the cure time and performance of the adhesive.
The wood subfloor also has a cement-based patch; under close inspection you can see very defined trowel ridges that appear to be the proper size notch. I would have liked to see the trowel ridges lying flat, indicating a proper weight roller was used to ensure transfer of adhesive to the back of the tile. The difference in subfloor porosity is very apparent in Photo 3 when you view the backside of the removed tile. So let's pay more attention to our job site conditions because you the installer are truly the lasting impression left with the end users! Thanks again for reading "You Make the Call." Have a great day!
Bill Baxley has been a floor covering inspector, specializing in resilient, wood, and carpet products, for the past decade. He is certified by the Floor Covering Institute of Technical Services, and is CFI certified for residential and commercial installations.
In the October 2019 issue of FCI, INSTALL’s executive director John T. McGrath, Jr. and instructor David Gross share key lessons to ensure concrete polishing jobs are done right the first time, every time.