A micro-topping is a cementitious product that is normally used as a solution to repair old cracked concrete. It works best on inside applications and horizontal surfaces generating a smooth neat surface that otherwise will be almost impossible.
Micro-topping can be used over interior surfaces such as:
- Indoor concrete
- Shopping centers
- Open plaza
- Office Centers
- General interior surfaces
Applying micro-topping over concrete surfaces will generate a smooth surface and durable finish. Some of the advantages are:
- Easy to apply
- No additional additives are needed
- Superior coverage
- Outstanding bonding over concrete
- Excellent mold resistance
- Normally is composed of Portland cement
- Sometimes can be used as a filler too
- Only requires water
- Some products can be applied in a single layer
- It can be colored
How to Apply Micro-topping
Before the micro-topping is applied you will need to verify that your surface is clean and free of debris. It is important to remove residues of chemicals, concrete traces or any other chemical reaction that are showing up on the surface.
Sometimes it is recommended to clean with water, acids or water blasting to remove all small particles that might prevent a proper bonding. Some companies can offer a specialized product to apply before the micro-topping is placed so you might want to learn more about the product you are buying.
Micro-topping: Surface Preparation
It is extremely important to repair any irregularities, holes, major cracks or voids that the surface is presenting before applying the micro topping. Sometimes the extensive repair is needed or some leveling compounds must be applied before the micro-topping layer.
The product shall be applied between 50 and 100 degrees Fahrenheit to ensure proper bonding is obtained and that the characteristics are not being affected by high temperatures. When the temperatures are too high, the surface must be cooled or the treatment needs to be postponed. Be sure to spray some water over the surface before applying it.
Micro-topping: Mix and Apply
Using a variable speed mixing drill begin by adding water and the micro-topping material. Remember so not overmix material or mix more material than the one that can be applied in 20 minutes.
The surface over which the micro-topping will be applied must be dampened and then using a squeegee or steel pool trowel start applying the material. Be careful to reduce trowel tracks although they can be smoothed later using rubbing stone after the material has been set.
Apply sufficient product to cover the concrete surface in one single pass. Once the product starts to dry, you must go back and smooth the surface using a steel trowel. Be careful not to start before the product has started to dry out.
Additional Concerns of Micro-Topping
Depending on the type of product used and the surface over it is being applied, a second might be required to achieve a smoother finish. It is important to be aware that weather conditions will affect the curing time of the micro topping.
High heat and humidity will accelerate the setting time so you might want to mix smaller amounts so it can be properly applied before it starts to set.
The majority of the products will start to set within 8 hours under moderate temperatures and humidity conditions. After sealing, allow approximately 24 hours for foot traffic and another 72 hours for heavy traffic. As a final step, you might want to apply some color to the surface so it can present a homogeneous appearance.