In the construction world, the use of concrete sealers, concrete admixes, and curing compounds con-tinues to increase. In the course of a week, it is not uncommon for me to be asked to look at the spec sheets of these products and to see if they are acceptable to have flooring installed over them. My answer is always the same, the flooring industry (flooring, adhesive, & patching manufacturers) does not accept the use of these products.
Why is this? These products can be possible bond breakers, not allowing the patch, adhesive, or mortars to bond directly to the concrete subfloor. The sealers, concrete admixes, and curing com-pounds can be made up of materials that do not allow the setting materials to properly bond. They act as interference between the setting materials and the subfloor.
The success of any installation where flooring is directly bonded begins with identifying potential bond breaking contaminants and successfully removing them. Curing compounds, sealers, coatings, paint, existing adhesives, remaining residue from previous floor coverings, grease, oil, dead cement, surface laitance, dust, dirt, etc. should all be viewed as potential problems.
What exactly are sealers and curing compounds used for?
Sealers are designed for a walking surface of concrete to control dusting and not as an underlay-ment.
Curing Compounds are designed to hold the mix water in concrete for hydration purposes. This is why you may have a low Calcium Chloride Test reading a very high RH Probe reading. Curing compounds are supposed to degrade from the surface of the slab, over a period of time, either through oxidization or ultraviolet degradation, allowing foot traffic to walk the residual off.
The problem with curing compounds is that they are supposed to be applied in a very thin layer (1–1 1/2 mils thick). In many instances the coating is applied too thick and does not degrade in the allot-ted times, which prolongs the start of the concrete drying process, thus delaying the start of any flooring installations. Some curing compounds are self-dissipating, but generally require sunlight or UV light for this to occur. Ultra Violet (UV) light and traffic over the surface of the slab will cause these materials to break down and disappear. However, since each one of these materials dissipates at different rates under a variety of jobsite conditions that can occur, you can never be absolutely sure that 100% of the chemical has dissipated. The amount of time for degradation is dependent on

time, exposure and thickness. Even when degraded, the pours of the concrete are generally filled by the curing agent that has not degraded. Even worse is a combination cure and seal product which is difficult to remove. These are normally solvent-based products and when applied too heavily will retain the residual solvent for a long time. These types of products have also been known to attack flooring adhesives; even one year after a flooring product was installed.
Parting Compounds are used in concrete tilt-up construction (see photos below). These com-pounds can be oil, silicone, wax or soap-based. Also known as a “bond breaker” they prevent the tilt-up wall, which is poured on the surface of the concrete slab, from sticking to the slab. Bond failures are caused by this residual not being removed from the concrete slab surface.

One simple test to determine if there is a coating of sorts on the concrete slab is to apply several drops of water to the slab surface. If the water beads up on the slab surface, this is an indication that there may be a bond breaker or sealer of some kind.
Concrete slabs where these products have been used, need to be mechanically abraded (sanded, grinding, & in some cases shot blasting) to be sure the residual compound is removed, especially along walls and where foot traffic is minimal. The concrete industry is gradually discovering that wet curing works better than a curing compound or sealer.
Flooring, patching, adhesive and setting material manufacturers do not and cannot keep up with the curing, parting and sealing compounds that are used on the surface of the concrete. These products impact how an adhesive bonds to the concrete and, in some cases, are incompatible with adhesives.

The resilient flooring industry has an ASTM Specification, ASTM F710 Preparing Concrete Floors to Receive Resilient Flooring. In this specification, it states “Such agents, in many cases, form a surface film of oil, wax, resins, or a combination thereof, that tend to obstruct the bond between the concrete and the adhesive or may trap moisture in the concrete which will be re-leased at a future date, or both, causing adhesive failure or other problems related to excess water vapor between the flooring and the slab.” The concrete must be free of dust, solvent, paint, wax, oil, grease, residual adhesive, adhesive removers; curing, sealing, hardening, or parting com-pounds; alkaline salts, excessive carbonation or laitance, mold, mildew, and other foreign materi-als that might prevent adhesive bond.
Below, are the statements from flooring manufacturers addressing the use of curing compounds and sealers;
 Armstrong: When curing, sealing, hardening or parting compounds have been used, the fol-lowing general statements can be made:
If they contain soap, wax, oil or silicone, they must be removed before a resilient floor can be installed. They can be removed by using a terrazzo or concrete grinder, by sanding with a drum sander or by using a polishing machine equipped with a heavy duty wire brush.
 Flexco: The substrate must be free of moisture, dust, sealers, curing compounds, parting agents, residual adhesives, adhesive removers, hardeners, resinous compounds, solvents, paint, wax, oil, and grease
 Metroflor: The concrete must be free of any curing compounds and sealers. Remove any curing agents and sealers from concrete surfaces.
 Tarkett/Johnsonite: The surface must be free of all solvents, paint, grease, oil, wax, alkali, sealing/curing compounds, old adhesive, and any other foreign material, which could affect the installation.
 Mannington: Surface contaminants should be considered as any substance that will interfere with the bond of the floor covering to the subfloor, such as curing or parting compounds, sealers, paints, oils, solvents or existing adhesives
 Forbo: The substrate must be free of all foreign materials including, but not limited to, dust, paint, grease, oils, solvents, curing and hardening compounds, sealers, asphalt and old ad-hesive residue.