How to Float Concrete

Concrete making is of different process, it serves different purposes, even though it is a visible project such as sidewalks, driveways but requires finishing. However let’s have a better understanding of what concrete is all about before going further to explain how to float a concrete. Concrete is a composite rocklike building or construction material made from the mixture of different building materials like cement, water, aggregate sand or gravel in required proportions. A Cement is an essential binding tool that helps solidify other concrete elements in a construction job.

Once the concrete is mixed, it will start to set or position itself for a solid body within a couple of hours. Here is one of the best ways that experienced engineers’ floats concretes to achieve a standard solid concrete.

Prepare form

The first step thing to do while trying to build a mold that will contain the concrete; this process can come in any way. Most concrete floaters use pieces of softwood to do that; the required size of wood should be about 25mm thick and extend a little beyond the size of the concrete base.  Look for an edge for reinforcement which should be a drive of around 30 to 60cm intervals; it is essential that you watch out for the spirit level so that the base will not end upsloping. Make the following tools available as you prepare to cover the bottom of the form to get 10cm of hardcore, stone, gravel, or preferably crushed brick to support the form.  The reason for hardcore is to form a stable base at the same time allows water to drain from the wet concrete. 

Pour concrete

The next step after you have successfully created a form is to pour concrete; there is no much to explain with this as the only process required is to pour the concrete you have mixed with a spade and make sure it reaches all corners of the form.

Screed Concrete

Screed board is the tool used at this stage; the work it does is to level the concrete by pulling and pushing it across the concrete with a back and forth sawing motion. If there is a trough the screeding board could not do, then you will need the help of a trowel to balance the job.

Concrete smoothing

Here is where you will need a Darby; you will need to use a darby immediately after screeding. As you are looking to smoothen the concrete with the Darby, sweep the darb over the overlapping areas of the concrete to fill any small holes left by screeding and level surface. Dabbing helps to smoothen the concrete and by forcing more substantial concrete position themselves. 

Allow the surface to dry

During the screeding process, the water in the concrete will bleed out and sit right on the surface of the concrete for a while before it finally dries off.  Do not perform any task while the water is still floating because if you do anything, you will end up scrapping away the water when it still has the chance to sink; this may not allow the concrete to get stronger make it strong and let the concrete lose the original composition of the mix.

Float concrete

This process requires that you sweep a magnesium float across the concrete in wide arcs while you hold it at a slight angle facing away from you. Try as much as possible to press down on the back of the edge as you go to carry on from where the Darby left off so that the job can end up being smooth.

Add texture

In a situation where you are feeling like you want a more textured concrete and have a non-slip surface, change the magnesium float for a wooden one so that you can arrive at a slightly rough finish.  In case you are not comfortable with that, there is an alternative; you can get a broom to use across the slab in one particular direction to create straight lines. Do not forget to wash the broom immediately after use so that it can be relevant for use some other time.

Round off edges

The edging tools allow you to walk your way across all sides of the slab while you press down with long so neatly separate the concrete’s borders from the wooden form.

Trowel concrete

Hard work requires an excellent finish to get a good finish on the job done. Use a steel trowel after you have noticed that the water has drained on the concrete and the material is getting hard. Swing the trowel across large circles, pressing it down on the concrete as you hold it almost flat. Do not do these more than three times, so that you will not mistakenly destroy the whole job. 

Guide the concrete

Keep the concrete moist for between five to seven days to slow down the setting process and allow the concrete to come out strong. The best ways to do this is to make use of a sprinkler and cover the concrete with polythene or apply a curing compound. After applying the curing mixture if that is what you prefer to use, leave the concrete for at least four weeks. With this, your mind will be at rest that you have arrived at something great.

Floating a concrete is as easy as explained, you may have come across some other means of doing it. There is no problem with that, but this guide is the best if you are looking to learn how to float a concrete as the professionals do.  

Different Types of Float

Before we can go into different kinds of floating, let’s first understand what floating means so we can have a better understanding of what it is all about. Floating is nothing but a small board made of either of plastic, rubber, wood, or metal that has a curved handle. It is a tool specially made for plastering, particularly to a house, to level out irregularities on the surface of the wall. Floating is a universal tool applicable in any part of a working environment; field managers’ use it to plaster both the inside, outside of a building, on ceilings or rendered walls.  However, for reasons not well explained, some people mistake or believe that a float and a trowel are the same or probably perform the same functions. It’s not true as we will be explaining to you in this piece the difference between a float a trowel.

Differences between a float and a trowel

A trowel is a tool whose plaster carrying part is made of a stainless steel or carbon steel usually used to scoop wet plaster before being applied against the wall or ceiling and spread smoothly. A float is a handy tool that has sharp edges; it is a flexible tool such that plasterers can turn its side to cut a clean edge in situations where two faces meet. Depending on the level of experience and choice, most plasterers prefer to make use of a spade instead of a float because there are many ways to go about a plastering job.

However, float is a plastering tool with lightweight pale grey metal; it has a handle made of different categories of features like plastic, sponge, rubber, wood, or magnesium. The professional look of a finish depends on the kind of float used to complete the job, as it helps make a job look firmer and giving out the required texture.

Different types of float

After we have been able to explain what a trowel and a float is, the differences between them and their areas of specialization. It is not time for us to know the different types of float used by plasterers to carry out their professional jobs. Note that the use of a float depends majorly on the professional experience of the user. Let’s look at the different types of floats.

Plastic float

Most plasterers prefer to go for a plastic float; the reason is self-explanatory. Every plasterer goes for it because they are lightweight, durable and flexible to use. It is of two different categories depending on the choice of the user; it has a lightweight and small size used on plaster while the weighted types of it are perfect for use on concretes.  The faces are either textured or smooth; the textured ones are usually used for render and concrete as the smoother ones are best for floating plaster according to users.

Sponge float

Its surface looks really like a sponge, this float can be used directly on the surface of concrete but precisely, and in most cases, it is used to clean the surface of tiles. Usually, they are also useful for exterior purposes.


Rubber float

The sole purpose of a rubber float in a plastering job is to grout a wall and applied on floor tiles. Also called grout floats, rubber float is rectangular. Some are of a pointed nose so they could reach corners and behind pipe, particularly when you are looking to grout some crucial areas of the house like bathrooms and kitchens.

Wooden floats

Wooden floats have a wooden hand, and it is available in the form of a handy texture just for the sole purpose of rendering and plastering. Wooden floats are generally used to prepare the surface of the topcoat. They are available in different sizes, just like the plastic floats; they are usable in some circumstances where there is rough concrete. 

Angle Float

This float has the smallest size among all categories of floats. Angle float is constructed with stainless steel designed flexibly to allow usage in all corners of the room as a user tries to trim off pieces of uneven plaster. The lipped edges are the advantage that angle float has which allows it to penetrate edges, most especially edges that form 90 degrees.

Magnesium float

This float comes with either a square or a round trip popularly known for smoothening out a concrete floor. They are available in different sizes, durable and usually light in weight.

Bull float

A bull float has similarities with magnesium float; it has a long detachable handle used for concrete floating immediately after screeding, the primary essence of a bull float is to level ridges and also fill voids left by screeding operation.   


We will not forget nor avoid mentioning darby even as many professionals have a lot of arguments about it whether they should consider it a float or not. But the fact remains that it has its function as a float. You can find it as wooden, metal or plastic float with a long blade that extends as long as up to 96’’ which is around 240cm. It’s useful at the early stages of plastering for straightening plaster or render.

Spiked float

This tool is also called nail or scratch float, why is because it has extended iron on its surface, which looks like nails. Users use it to make texture on outside walls.



Devil float

A devil float is also called a hand float, usually made from of wood with screws or nails to help hold its handle to the body. It is used to close the surface of the backing plaster. The process of doing that is called rubbing up, which also means prepare a plaster for rubbing coat.

A float is a popular tool used by construction companies for the sole purpose of making an excellent finish to their work as this is the only tool capable of bringing out the beauty of their job. Its relevance is the very reason why it has different types so it can be useful for various purposes.

As you try to complete a concrete pour, you must make sure the finish looks flat and professional as possible as you can. You need a power floating machine to arrive at an excellent finish; you will only be able to do this by imploring the service of a hand concrete float and proper technique. In some cases like trying to complete a slab it may be a bit difficult and labor-intensive but in other to make things easy you can alternatively make use of a power trowel popularly called power float or helicopter.

What is a power trowel?

Power trowel is a concrete smoothening machine designed basically for smoothening and leveling the surface of the concrete to an exceptionally high tolerance level. Power float help to cover up all little spaces that may want to surface in a concrete mixture, but the fact is that the operator must have already laid, levelled and compacted the concrete before the need for a power float.

Power Trowel Options

What makes a power float useful and effective is its ability to work perfectly and reliably. This machine provide a simple method of ensuring that its blades are balanced and easy to adjust whenever they mistakenly get out of balance. Unbalanced float are usually unstable and most of the time give the operator a big challenge when he tries to make a high tolerance finish. Power float engine are available in two different categories depending on your preferred taste, some are made of diesel engine while some are petrol engine. The engine size also varies between 5-10 HP for pedestrian float while larger sizes are between 20-25HP.

Float sizes

Floats have different sizes, depending on the choice of the user and purpose of use. Let go through the various size for you to have a good understanding of multiple categories of float machines. Here is the most popular size you can find in the market.  Floats that have a diameter of 0.6 meter is an edging float used mainly for through tight areas.  A little bigger than that which is about 0.9 meter is a standard one used in strategic places like factories while those that measure 1.2 meters is for large floors that need high-quality finishing.

Blade selection

Floats have blades that they use for their finishings; depending on the kind of application that you want here are different categories of Blades that float uses. 

Space float blade: this is the first kind of floating Blade used for finishing

Float pan: this is an alternative to Float Blade

Combination blades: it has two sides, operators use one of the Sides for finishing while they use the other part for floating, that is why it is called the combination blade.

Timing and methods of use

Floating needs to be taking seriously and started on time; the float operator must exercise enough patience to make sure that concrete is hard enough before placing the float on it. However, the operator needs to leave a footprint of about 3mm while standing upon the surface of the concrete to knows if the concrete is hard enough for the float. The reason is that, if the concrete is still wet the machine will tear off the surface of the concrete, and if it is too dry it will prevent the engine from trimming high spots and fill lows effectively.

The timing and methods are of two stages, which is stage one (Floating stage) and stage two (the finishing stage).

Stage 1: the power floating machine is fitted with either float pan or blade. As the pan or Blade starts to work, floating ill start from the top of the concrete to the bottom, as the operator moves back, the Floating machine cleans off the footsteps of the operator as the speed needs to be consistent and slow.

Stage 2: the moment the surface has received enough floating; the floating blades are detached from the float and allow the finishing blade to do the finishing touch to the concrete. The bladed are positioned to suit the Concrete, increasing its angle after each pass, and distinctive aspects are required most of the times to arrive at an excellent finish.

Take precautions

In other to avoid problems, there is a need to be careful at every stage of floating, being careful will let you know that there is need you cover the required floating areas adequately with concrete. It is a good idea when you make use of Speedcrete as you try to float the concrete edges, joints around obstructions. These steps are necessary before proper floating. Doing this will let you be conscious of large spots; in this wise, the power float will not be able to take off excessive significant high points in the bay.



Advantages of a power float finish

Using a trowel on a poured concrete is an excellent step to take. It gives a smooth and attractive finish to a job and also helps to structurally level minor imperfections and improve the density of the surface. Making a standard power trowel these days requires an industrial use of both a hand float pan and a finishing blade in other to arrive at a desired smooth concrete slab. Let’s have a brief discussion of how to use these two powerful floating machines (Float pan and blade) to achieve an excellent power float finish.

The first thing is that the float pan must be attached to the power trowel. Once the concrete is ready, pull the machine before you slowly from one end of the slab to the other. Ensure you are walking backward as you pull the engine to yourself so that it can easily clean off your footprints. Lastly, maintain this line pattern until you finish the whole process. I hope this guide helps you understand one of the best ways you can power float your concrete.