FACTS ABOUT ALKALINITY
An excess amount of alkali on the surface of the concrete can prohibit the bonding of a latex adhesive floor. The degree of acceptable alkalinity will vary with the particular adhesive utilized. Therefore, it is best to determine the level of the alkalinity present on the surface. The following simple and inexpensive test can be used:
1. Dampen several scattered areas of the floor with distilled water. Wait five minutes.
2. Place pH paper with a range of 0-14 on the wet areas. The paper will change color to indicate the level of alkalinity present.
* If the color corresponds up to 8 on the pH scale, the glue down can proceed.
* If the test indicates a level above 8, then the surface is more alkaline. The higher the number, the higher the alkalinity level. In that event, it is advisable to ascertain from the adhesive manufacturer the level of alkalinity suitable for their product. Request their recommendation for a method to reduce the existing alkalinity in the floor to a safe level.
* Alkali salts or high concentrations of surface alkalinity may be removed or reduce by thoroughly rinsing the surface with water. Rinsing should be repeated, changing water frequently. The concrete subfloor should then be allowed to dry and retested. Continue this procedure until the desired results are obtained. Generally, test results for pH less than 10 are considered acceptable for the installation of most flooring materials. If the concrete surface is degraded or softened from the effects of alkalinity, mechanical surface preparation should be accomplished utilizing approved OSHA work practices and following any governmental regulations or ordinances for same.
*Note: Generally, if alkalinity salts are found deposited on the surface it is an indication that an unacceptable moisture condition may exist.