Floor Flatness and Working with Concrete Trowels
Concrete trowels are power tools used to even out concrete pours and eliminate bumps and valleys on a concrete surface before it completely dries up. Many people either lease or hire concrete trowels for their floor flattening needs because these devices can be quite expensive to buy new for one-time jobs. Whether buying or leasing, the quality of your concrete pour will largely be determined by how even and flat the resulting surface appears. Flattening concrete surfaces depends on a couple of factors. Beyond temperature, wetness, and concrete mix, the trowels themselves also have a hand in the nature of the resulting surface quality. The following are the two most common trowels used in small to large concrete pours and the various ways you can get the most out of these devices.
When using a walk-behind trowel
As the name suggests, walk-behind trowels are operated by an operator who walks behind the machine, leading it to various areas across the floor while it evens out the surface. Walk-behind concrete trowels are suitable for relatively smaller surface leveling to medium square footage projects that will not involve too much time leveling. With these types of trowels, the blades and pans used are the most important consideration. There are mainly three types of blades used: clip-on float blades, combination blades, and finish blades. Many people recommend the use of combination blades for residential concrete flattening because of the good transition they offer between floating to troweling. Clip-on float blades enable the operator perform various tasks including embedding aggregate and compacting concrete for the next finish operations. Many people have also now taken up the use of float pans with these devices. Unlike clip-on blades, float pans smear the concrete flat instead of riding over humps and evening them out. The secret to using these concrete trowels is to maintain a pattern instead of wandering all over the surface.
When using a ride-on trowel
These concrete trowels involve an operator driving the machine over the pour while the blades even out the surface. Ride-on trowels bring about higher flatness levels due to the extra weight the machines press on the concrete. They are suitable for medium, to large pours—basically more extensive surfaces with fewer obstructions such as doors and narrow corridors. It is probably recommended to have two of such machines or more so that riders can overlap each other's tracks and even out the windrow effect from each machine. The windrow is the area between the two rotating pans of the machine that remains un-flattened. As the work continues, concrete further hardens, and you should always increase the blade pitch of the machine progressively to increase pressure applied to the hardening surfaces. Remember, there are different types of ride-on concrete trowels and you should choose these based on your floor sizes, desired finish, or even the ability to pan float.