Coating of cement floors

After inspecting a floor for an applicator to determine its suitability for coating, I feel that putting down a couple of essential pointers would be appropriate. Previously uncoated cement screed floors need to be fully cured, dry, free of oil or dirt, and of a sufficiently rough profile before coating. Often calls come in from applicators or home owners after the coating has been applied asking why problems have occurred - all of which could have been prevented had these guidelines been followed.  Cement slab driveways and verandas (stoeps) are often thrown without a damp proof course below them - here the rule is simple - do not coat them.
Allow at least 28 days for the cement topping to cure, then check the moisture level with an appropriate moisture meter. The moisture level should ideally be below 12% as measured by  a Protimeter. Ensure that the profile of the surface resembles 100 grit sand-paper, if not mechanically abrade the floor using a floor grinder. This step will often remove surface dirt and oil at the same time. All dust should then be removed by sweeping or vacuuming the surface clean.
The first coat can now be applied - preferably thinned 10% by addition of the relevant solvent. Generally, a 24 hour drying time should be allowed before application of the first unthinned top-coat. After another 24 hours, the second top-coat can be applied. Depending on the coating type, there will be a specific time that needs to be allowed before the coating is subjected to heavy traffic.
Coating types vary from Water-based Acrylics to single pack Alkyd and Polyurethane-Alkyd enamels, then on to the Twin Pack Epoxy and Polyurethanes. There are cost and performance advantages related to each of the above options - check with your supplier as to which one best suits your requirements.