How to power float a concrete floor for a professional finish?
A flat and splendid result is what we are looking for when dealing with a DIY concrete pour. You can make this happen by pouring concrete gradually, a hand concrete float and a proper technique. Nevertheless, it would be highly laborious and tiring to finish a large concrete slab by hand such as a poured concrete driveway or a patio slab this way. For this kind of purposes, you can flatten and finish a concrete surface way more accurately with a power trowel, also known as a power float or helicopter. To carry on a project at home, a walk-behind power trowel will come in handy while wider commercial projects will probably need one or two ride-on power trowels. In this post, you will find some advices to obtain the best results when working with a walk-behind power trowel to finish a driveway, slab patio or any project that involves concrete recently poured.
Advantages of a power float finish
What does a power trowel do? Using a power float machine produces a flatten and pleasing surface, but it provides other benefits in addition to the superficial correctness, it prevents the structure from being crooked, fixes those little imperfections and enhances the density of the surface. A concrete power float accelerates the work much more than hand trowels. Besides, with a concrete power float finish, you won’t need to add another layer of finishing screed material.
Power trowel finishing techniques
There are two aspects that you need to take into consideration when power floating concrete: the machine’s condition and your technique will determine the finish result. In this article, we will continue with a brief explanation about how to use a power float and more specifically, how to power float a concrete slab properly.
The power trowel must be used at the precise moment
A power trowel or power float will flatten and finish your floor but remember that it must be used before the poured concrete has completely dried. Timing is a crucial part of the process and will influence the finished product. Power floating concrete while it is too fresh and wet can produce delamination of the material. Essentially, it will be torn up.
There are other aspects to consider such as the air temperature, the wind and humidity. These elements will affect how long it take for the concrete do dry, so we don’t recommend using a prescribed wait time, instead, here is a trick for you to check if it is the right time to finish with your power trowel: Step on the concrete, as long as your footprint is ¼” deep or less, with no bleed water or an insignificant amount, you can proceed with the power float. However, if the footprint has much water or is more than ½” deep, you have to wait a bit longer, but don’t wait until it is completely dried or it won’t work!
Float pans and finishing blades for your power trowel
Nowadays, standard power float includes a float pan and a finishing blade to soften concrete slabs. This is how you work with concrete power float finish with two attachments: first, attach the float pan to the power float. Once the concrete has been poured, pull the machine in front of you gradually from one side of the slab to the other, over to the side slightly and then again in a new row. Normally you will be walking backwards when pulling the machine, so it flattens your footprints while you work. Following a line-by-line pattern will help you to cover the whole surface.
Repeat the same action put from a perpendicular perspective, go widthwise if you first went lengthwise, following again the same pattern. Each consecutive pass makes the material denser and compact, and the surface smooth and nice.
Attach the finishing blade to the power trowel
When the two perpendicular passes with the float pan have been completed, you can get ready for the last step in power floating your concrete, starting with attaching the finishing blade. Repeat those two or even more perpendicular passes in the same way, starting at a 90-degree angle to the last pass that you made with the float pan. In this first pass use a flat finishing blade or a very slight pitch. During the successive passes, gradually increase the blade pitch to add more pressure to the concrete surface. A standard blade angle goes from 5 to 10 degrees, but if you perform more passes, these angles can be increased if needed.