Flooring Preparation
Epoxy flooring preparation is simple but time consuming. The key to a great finish is to get the preparation right and this is done by ensuring you are doing the correct preparation for the stresses the floor will endure. This is what causes about 95% of the problems that ever occur after a floor has been installed.
Points to consider are:
- Calculation of the GTL (Gross Traffic Load) IE How much traffic will the floor incur and is it a light or heavy load. IE are you going to constantly park two large 4WD’s on it or will it be used as a playroom and have small kids crawling on it each day?
- Is the substrate suitable to coat with epoxy. Most are, but before you get ready to coat it you need to know if the concrete is soft or hard? Sounds dumb hey because if you bang your head against the floor it’s going to feel pretty hard, but believe it or not concrete does vary a lot and you need to be aware of these variations because it greatly effects how you prepare the floor.
- Is the floor level? This one makes a massive difference to your finished product and how long it lasts. If it’s flat like a mirror then giddy up your job will be easy. (most aren’t by the way). If it’s more like the surface of the ocean then you need to level it either by grinding or by using a self leveling compound or both. Your contractor can check this for you. Remember single colour and metallic coatings highlight imperfections so you need a near perfect slab to get the best results from this floor. You can quite easily have a floor preparation tradesperson get a slab just about perfect for you to coat but this does add another layer of cost to the project.
- Has there been chemicals on it before, such as paint or oils? If so these will need to be removed and they must be totally removed or you will have problems in the future.
Acid Washing VS Grinding The Floor
The big question everyone always asks is: “Do I have to grind the floor or can I just wash it with acid?” The answer is it depends on the above points and some other factors we don’t have time to go into. If you only have a very light GTL you can get away with acid but make sure you do it extremely well. But if you want a guaranteed result that will last for years, grind that sucker! There is nothing that comes as close as removing a layer of concrete if you want to eliminate about 99% of the problems with a bad slab such as old paint, oil stains etc. Just remember this, acid washing cleans the top layer while grinding gives you a brand new uncontaminated surface to coat.
The picture below shows two sections of concrete. We did an acid wash on the LHS and put our grinder on the RHS. If you were epoxy what would you rather stick to?
BEFORE AFTER
Ok but what happens if you don’t have a grinder or it’s just too expensive to hire one, or your weird religion prohibits the use of one?! You then acid wash the slab and you need to do this at least twice to be thorough. Then once you have acid washed it you MUST hose off the slab at least twice to ensure you remove all residue of the hydrochloric acid. If you get lazy with this step you will pay for it later on when your coating peels off. Remember that epoxy doesn’t like sitting on top of hydrochloric acid residue.
If you’re still aren’t convinced about the dangers of not properly preparing your slab, take a quick look at these pics below. Probably 80% of our work involved repairing jobs that are not prepared properly and here are the consequences. These pics have all been taken in the last few weeks. It’s a real issue people so BEWARE of cutting corners!
BTW peeps we probably shouldn’t even post this info because we are kept really busy fixing these mistakes but in the interests of creating a world full of beautiful epoxy floors we wanna share!
