Do I Need to Screed a Concrete Floor?
Concrete floors can be found in a wide range of commercial and industrial environments including warehouses, factories, airports and residential settings.
These types of floors offer a wide range of benefits including the fact that they’re extremely durable, low maintenance and offer wonderful longevity that sees them last for years to come.
If you’re constructing a concrete floor, you may wonder whether you need to use screed.
The use of screed tends to vary depending on the specifics of the project, but in this article, the experts here at Concrete Supply UK will answer the question ‘do I need to screed a concrete floor?’
Read on to find out more…
What is screed?
Many people confuse screed and concrete, so it’s important to distinguish between the two materials before we go on to explain whether screed is required for concrete floors.
While they do share some properties, screed is much thinner than concrete and is predominantly used as a material to create smooth and consistent finishes. This is why they’re commonly associated with concrete floors as screed will often be used to even out any irregular or bumpy areas.
As a result of this, screed is made from fine aggregates to ensure this smooth finish, and will usually be much thinner when poured when compared with concrete.
Usually, it will be applied before the final flooring application is installed but in some instances, people will opt to use screed independently of other materials due to its versatility.
While the main purpose of screed is to invoke a smooth finish, in contrast, concrete is considered a structural product. This means its composition is much different as concrete needs firmer and harder aggregates in order to create the durability, structural integrity and strength that it requires.
Another difference is that screed is almost exclusively used for indoor applications, such as floors, whereas concrete is much more versatile and regularly used in a whole host of environments.
Ultimately, the main difference between screed and concrete is the thickness. While it is essential that screed is thin to achieve smooth finishes, concrete usually needs to be thicker to meet the construction requirements. With this in mind, it’s important to understand that they are two very different substances that should not be confused.
Do I need to screed a concrete floor?
Now, onto the question of whether it is necessary to screed a concrete floor.
This will depend on several factors, most specifically the condition of the surface you are working with.
If the floor is uneven, cracked, bumpy or damaged in any way, then it is usually necessary to screed the floor. This is because the screeding process will remove these imperfections and leave you with a smooth, consistent area to work with. If you do not screed the floor in these instances, then it’ll be harder to apply the final floor material (concrete in this example) and means that the floor is left uneven. Uneven floors are unsightly and could even be hazardous to those using them.
However, if the floor is already fairly smooth then people may opt to skip the screed. Usually, this will be done to save money as the use of screed will add an extra expense to the project.
If you’re in doubt, we’d always recommend using screed for a concrete floor.
This is because it will give you peace of mind and reassurance that the surface you are working with is as consistent as it should be and you will not experience any issues with it further down the line.
How to screed a concrete floor
Now we’ve explained the benefits of using screed for a concrete floor, let’s outline how the process works.
Below, we’ll provide you with a handy step-by-step guide explaining how to screed a concrete floor, giving you all the information you need to carry out the process effectively.
Prepare the area
Before you begin, it’s important to prepare the area you will be screeding. This involves measuring the area, mixing the screed and cleaning the space.
In particular, you should make sure the floor is free of all dust, dirt and debris. A dirty floor is harder for the screed to adhere to so be sure to rid it of this first. If you are using unbonded screed then you may also need to reinforce the layer the screed will be used on. The screed’s packaging instructions should provide information on this.
Divide up the floor
Before laying any screed you will need to divide the floor into sections. Working in smaller areas at a time will make it easier to level out the floor as you go along.
You can purchase specialist dividers to help you do this, or simply use long pieces of wooden timber that are cut to the height of the layers.
Apply a layer of screed
Once the room has been divided, pour a layer of your screed mix into the section of the room that is furthest from its entrance. Then, use a trowel to spread the mixture out and compact it with a screed board or straightedge.
Make sure the screed is properly compacted as poor compaction is perhaps the most common problem people come across when screeding a floor.
Level the screed
Sometimes, screed will be self-levelling but this is not always the case.
If not, you will need to level it yourself. To do this you can use a straightedge or piece of timber. Place your chosen tool over the dividers you lay earlier and tilt it until a corner can be used as a cutting edge. Then, use a sawing motion and move the tool from side-to-side to level the screed.
Repeat the process
Following this, repeat the process until every section in the room has been screeded. Then, you can remove the dividers and fill in any gaps you may spot.
Allow to cure and dry
Once you’ve completed the entire floor, you need to allow the screed to cure and dry.
The curing process will take around 48 hours. At this point you can walk on it but no heavy traffic should be used on the floor for at least three weeks until it has fully dried.
If you need screed or if you’re look for a specific type of concrete, like readymix or volumetric, then simply contact us today.
