Surface Preparation

Surface Problems Associated with Concrete: Grease and oils can create serious adhesion problems for coatings. Degreasing and washing may appear to remove the grease or oil, but in badly saturated situations residual oilsgreases seem to remain and may cause a coating failure in the future. While not a definitive test, pouring a glass of water on the concrete and watching what happens can provide a valuable clue to coating adhesion. If the water quickly and evenly soaks into the concrete the surface preparation may be adequate at that point. More on degreasing concrete below Moisture either in the concrete, andor migrating through the concrete can cause coating failure as well. Taping a sheet of plastic to the floor and looking for moisture to form under the plastic is a crude but common test for migrating moisture. Some epoxies will handle a wet or damp surface better than others. Note that crystals forming on the surface due to water migrating through the mineral rich cement can create forces of up to 1,500 pounds of pressure as they grow in size. Few coatings can withstand such