A lot of people don't realize that the surface they are coating needs to be prepared before they start. Apparently, preparing the concrete is a must if you are planning on coating them anytime soon. This is crucial if you want to ensure a longer-lasting coating.
However, we understand that it is not easy to do concrete surface prep if you have no idea how a professional does proper surface preparation in the first place. Some might think that surface preparation can be done quickly and easily. However, for proper surface preparation to work, you need to take your time to understand how to execute it properly for the coating bonds to adhere and ensure a successful coating application properly.
So, to help you in the preparation process, here's a step-by-step guide plus some tips that you need to know for better results.
Preparing Your Concrete Surfaces For Coating
You might not be a contractor yourself, but definitely, you'll still be able to do proper concrete surface preparation as long as you follow these steps for a properly prepared surface, whether you're working on a home improvement project for polished concrete floor coatings or any other concrete surface.
1. Safety Equipment Is Your Friend
Learn how to use and wear proper safety equipment like masks and gloves when handling coating materials. Depending on the coating job, some projects may require added protection. Since you must remove all dust, dirt, and residue from the concrete surface, it is important to use proper protective gear, especially because concrete can cause irritation if inhaled or absorbed by the skin, so don't forget this step before beginning any coating job!
On the other hand, if your concrete surfaces are rusty, be sure to sand them down first before washing away any dust or debris that might be on them as rust stains could stay behind on the surface, giving it an unsightly appearance once the paint is applied.
2. Clean The Surface First
Before you start concrete surface preparation, you would want to start by cleaning the concrete or removing any dirt and debris on your concrete floors. You can do this by using a pressure washer and cleaning solution and rinsing it afterward with water. This will ensure that your top surface is free from any contaminants and will help ensure a better bonding of the coating.
Note that you need to know how to properly use pressure washers as they can be very dangerous if used without proper training or knowledge on how to handle them.
Depending on how dirty the concrete surface is, you can pressure wash it using low or high-pressure spray heads to clean your concrete. Another thing you need to remember is never to leave any electrical equipment near wet surfaces or let water pool around them so it doesn't accidentally cause electrical shock, which may lead to fatal accidents.
Moreover, it is also highly advised to rinse your surface with a garden hose before using the pressure washer, as this will help remove loose debris and dirt. But if you don't have a pressure washer, but your surface is still really dirty and has lots of debris stuck on it, you will need to remove that debris before you can proceed with concrete surface preparation. To do so, use a broom and brush away as much of the concrete dust.
3. Let It Dry
Now that you're done with surface cleaning, you need to let it dry before you do further preparations. Concrete needs time to breathe and "cure" itself after being wet from pressure washing or rinsing, so allow it to dry first. You can speed up the drying process by using fans and dehumidifiers.
However, if you pressure washed the surface too early before it had dried completely and there is still moisture on your concrete floor or surface, solidifying the concrete coating will become challenging, if not impossible. Since concrete absorbs water easily, experts recommend that these areas be left for a few hours so water can dry out completely after cleaning it. This will set up your surface for a better curing process and make it more resistant to damage caused by chemicals used in coating products. Concrete surfaces are naturally soft, so keeping them damp can cause small cracks if insufficient drying time is given.
4. Start Preparing The Ground With A Brush
Next, you should start preparing the ground surrounding the area with a broom using a stiff-bristled brush. This will remove any loose particles that may have been stripped during the cleaning process. You can then sweep up these particles and throw them away in a disposal bin before doing further prep work.
5. Check Areas For Cracks And Cockles And Repair Any Unsound Concrete
Now that your surface is free from surface contaminants, it's time to check the exterior surface for cockles or small cracks you need to fill in using a concrete filler or patching material, so they don't leak out when you apply coating products over it.
Unsound concrete should be removed and any surface defects, such as holes, spalls, cracks, and other surface flaws, filled with a commercial cement-based grout, epoxy compound, or other proprietary patching materials. The best way to know what kind of material would work well with your concrete surface is to do some testing first. Apply small amounts on your test area underneath your concrete pavers or blocks before going all-out.
6. Do Some Clean-Up Using A Wire Brush, Then Cure For 24 Hours
Use a wire brush to remove small chips left on your surface after applying the concrete filler. By brushing it, you can ensure that the patching compound is smooth and even with the rest of the surface so you can apply coating products better onto them later on.
Now that all preparations are done, you need to let it cure for 24 hours using a curing compound or product to protect your new fresh coating from damage due to moisture.
Make sure to use painter's tape for proper masking when preparing the edges surrounding the area you're coating. Then, you can remove the tape once your concrete is thoroughly dried and hardened before cleaning up any excess compound with a vacuum cleaner.
7. Surface Profile Your Concrete By Roughening The Slick Surfaces As Much As Possible
In addition to removing all dirt, dust, and grime from the surface, you should also roughen up those slick surfaces as much as possible too so that they can bond more effectively with the floor coating. Shot blasting, acid etching, sandblasting, scarifying, and grinding are the most common techniques to profile concrete surfaces properly.
Acid Etching
Acid etching is a more gentle method of roughening up your concrete surface since it uses a diluted acid solution to eat away at the top layer. It works best for sealing and preparing new or old poured surfaces that have been stained or deteriorated by chemical exposure or those with no bond coat on them, to begin with.
Shot Blasting
On the other hand, shot blasting uses a shot blasting machine or hard steel balls to blast away your concrete's top layers. This is effective for removing paint and rust from old surfaces or large surface cracks because it can easily reach them through its aggressive abrasion power. However, this method might cause damage around the edges of your concrete pavers, so you need to handle them with care.
Sand Blasting
If you want to use a more advanced and controlled method, sandblasting is your best option. This is more versatile and can be done on a large scale than other methods because of its air blasting power. It works by using pressurized sand to blast away the concrete's top layers without damaging it or stripping off too much material in one go. Still, you need a constant water supply nearby since this method generates a lot of heat from friction.
Grinding/Scarifying
If you're working with large areas, grinding and scarifying are the best methods to use for surface profiling. Grinding is usually done with a vertical grinder, which can be as wide as your floor, and works best for removing paint from large surfaces. Scarifying also uses abrasive power, but it does so through rotating blades or disks instead of blowing dust particles at the surface like sandblasting does to cut away from its top layers.
Once you are finished, rinse off the entire surface to remove any remaining dust or particles before applying your coating product evenly.
Use Tsp For Better Results
TSP or trisodium phosphate is a powerful cleaner that breaks up grease and grime. Still, it has a strong chemical smell, so you should only use it outdoors with plenty of ventilation going on to keep fumes from being harmful to anyone working around them.
If you don't own a pressure washer, you may want to use a wire brush or steel wool pad to scrub the surface. People have also used sandpaper for this purpose. Still, many prefer using steel wool because it does a better job of scuffing up their surfaces without scratching or harming any part of them under normal circumstances.
8. Check The Surface And Ensure That It's Dry
Make sure that the concrete surface is dry before applying any coating product over it. If you're going to apply multiple layers, make sure that there's enough drying time between each layer. Leave it for at least 24 hours after finishing your final coat before doing anything else with the newly-coated concrete floor.
Make sure to remove all wires and lines from the area, as painting over them can be difficult due to how thick coating products tend to be. To remove such things, you'll need putty or a knife for this purpose so you can cut those objects out of your area before covering them up with paint later on.
9. Always Use A Primer First Before Painting Your Concrete Surface
You may want to use a primer first before applying any paint onto your concrete surfaces if they're particularly porous and rough because primers usually work well for various types of surfaces, including concrete.
Use only one thin coat, though, as applying too much primer will result in drips and runs, which can ruin an otherwise professional-looking painted surface that you could've saved yourself by using less primer in the first place. Most people don't like using primer anyway. Still, surface preparation matters because inadequate surface preparation would show on concrete floors or any concrete slab if surface cleaning is not done beforehand. From air pockets to a poorly profiled surface, the finished product will never look as polished as it should be if not adequate surface cleaning is done.
Final Thoughts
Every square inch of your concrete surface is very important. Whether it is your garage floor, a concrete porch, or a patio, you want to ensure that your surface is properly prepared before applying anything over it. While there are many methods, you can apply to have a flawless concrete floor coating and an aesthetically pleasing finished product. These tips should help you achieve the best results possible.
