While building a new house or repairing the old one, you might face a need to install new flooring in the house. You may be required to lay a fresh layer of screed on to which your new type of flooring will be installed. Even if your flooring is wooden or stone, it is necessary for you to lay the screed properly so that the flooring stays tough and damage proof for a long time.
The process of laying the screed is a simple act of pouring a well-blended mixture of ordinary cement and screed along with some water. The entire mixture is made such that its components are added in a particular proportion. Any change in the levels of the components affects the properties of the screed, rendering it ineffective.
The screed used provides a very strong sub-base which gives all the necessary support to the upper flooring which is laid onto it, so it works as a final wearing surface.
Although the process of laying screed sounds very easy, it is a particular skill, which has to be done with precision and caution. It not only includes mixing sand and cement, but also has much more to it.
Laying screed is an essential step which plays a significant role in making sure that the end results of the entire flooring process is well achieved such that the floor remains durable for many years. This is because well-laid screed can extend the life of the floor and can do wonders to its quality, but if it is not laid correctly then it damages the quality of the floor and compels you to spend quite a lot on its repairs.
It is essential to know about screed and the laying procedure before carrying it out yourself. Let’s take a look at that in further detail.
Essential Steps for Laying the Floor Screed Correctly
In general, there are five steps which assist in laying the floor screed. They are as follows:
- A Knowledgeable Contractor:
Before you even start with the entire process of flooring and laying the screed, it is essential to get the right contractor on board with you. The contractor must be such that they are well equipped with good experience and knowledge in laying floor screed. The contractor must be such that they use the best technology for their working purpose and are professional in their approach.
The contractor must have proper management skills since the job of laying screed is very messy and full of nuisance. It includes making a proper plan, choosing the right kind of screed, mixing is correctly, applying it with precision, completing the work in decided time, protecting it until it dries and sticking to the budget.
- Choosing the Right Floor Screed:
There is a huge variety in floor screeds and even more variety in their brands. Choosing the right screed for your floor can become a tedious job for you. Hence it is essential to know about all the different type of screeds, the material they are made of and their other features. The time when you will know everything about the different screeds in the market, that time you will be able to decide which screed suits your requirements the best.
Here are a few screed types that can be selected according to your needs and requirements:
- Traditional Screed:
This is a standard screed which is made of cement and sand mixture at the ratio of 1:3. Usually, it is used to create a defined layer, such that it can lead a way for the installation of final flooring, such as wood, tiling, vinyl, etc. These screeds are generally used in hospitals, homes, schools, retail, etc.
- Flowing Screed:
A flowing screed is also known as a self-compacting or self-levelling screed. The major advantage of this screed is that, it can be placed easily and its end results are quite reliable. However, this type of screed is not recommended in the areas which are prone to get wet on a frequent basis. A flowing screed is neither used as final wearing surface nor is it compatible with the cement products.
- Structural Screed:
Structural screeds can be used to install precast floor surfaces. However, it is essential to seek assistance from a structural engineer, to get accurate calculations and specifications before installing them. This is done because the information provided by them assists in deciding the flexural strength, load requirements, bending moment, etc. Thus laying screed using all this information can give you better results.
- Fast Drying Screed:
This type of screed can be selected when you don’t have much time in hand to complete the entire project. During such time, the industry benchmark of 1mm per day cannot be followed. The biggest advantage of using a fast drying floor screed is that, the final floor finish can be completed approximately within 3 days of laying the screed.
- Mixing the Screed Correctly:
The screed has to be mixed in proper proportions to harness its benefits. For this there are various mixing options available. There also are ready mix screeds available for your use. While choosing between a site mixing and a ready mix screed, you need to take into account the factor of feasibility. This factor entirely depends upon the location of the site and the space available at the site for mixing the screed.
Ready mix screeds can be an excellent option in work sites wherein it is difficult to store all the required materials. But, one major drawback is that, there are several hurdles to get the screed on site in time, which can result in a considerable amount of economic and time loss which cannot be afforded.
Major contractors prefer mixing the screed on the site as it is an economical and an efficient way of working with the screed. Also it cannot be ignored that it is mixed properly and by a skilled workforce present on the site.
Usually, there are three methods that are used for site mixing. They are:
- Hand Mixing
- Free Fall Mixers
- Forced Action Mixers
A good screed is made when you blend it properly such that the cement, sand and additives are mixed evenly. When they are rightly mixed you get an even subfloor on which the flooring materials such as carpet, vinyl, wood, stone, etc. can be installed properly. For this, the method of mixing plays a significant role as it determines the quality of the screed.
You can conveniently use the hand mixing techniques and free fall mixing techniques when you have to yield screed for smaller paces. But these methods fall short and are inadequate for covering large areas. Also there can be problems in the ratio of the mix since the workers won’t be able to gauge it properly while mixing screed for large areas.
To tackle such scenarios, forced action mixers, also known as the screed pumps can be used. There are companies and dealers which give the option of either liquid screed pump hire or purchase. Thus you can make good use of it while laying the screed as it not only mixes the screed in huge quantities but also gives you other benefits, such as,
- Superior Quality:
A screed pump which makes the use of forced action mixing technology produces screed which is generally of higher quality and homogeneity while compared to the screed yielded by hand mixing or free fall mixing. Also the screed is mixed uniformly such that the cement and additives are evenly distributed through the sand.
The screed resulting from the hand mixing or the free fall technique leads to ‘balling’ of cement which makes the screed week and poor in quality. Modified screeds like FlexiDry are found to perform at its peak when force action mixed using screed pumps or the smaller pan mixers.
- Higher Efficiency:
Using the screed pump is easier and quicker compared to hand mixing or free fall mixers. Screed pumps can efficiently mix large volumes of screed in a short time and is ideal for screeding large areas.
The screed pumps can mix the screed in very less time and so are ideal to use while taking huge projects in hand which involves laying screed over a large area. Also it is easier and quite convenient to use the pump rather than the other two methods of screed mixing.
- Ideal when access to work site is difficult:
Screed pumps are suitable for complex constructions and buildings which have difficult access points from where the materials cannot be carried up manually. Thus the screed can be mixed well in the pump and the ready screed can later be carried by the workers.
- Minimal dust pollution at the work site:
Mixing the screed in screed pumps helps in keeping the work premises cleaner as compared to the traditional mixing methods. This also keeps the dust and dirt away from the site which is generally caused while using the other two methods.
- Right Process of Installing Screed:
To achieve the desired results, it is important to conduct the process of installing floor screed in an organized manner. There are various steps which have to be followed while you prepare to install the screed. The steps are as follows:
- Checking whether the specifications are fit for the purpose
- Ensuring that the substrate is able to receive the screed
- To check if the access and outlet suits the screed installation and other materials
- Checking if the building is waterproof
- Recording all the measurements to ensure appropriate depths are achieved.
- Mixing the screed in correct proportion
- Applying screed properly
- Keeping the entire work area clean.
- Right Measure for Protecting Screed:
This is the last step while laying the screed but remember it is also just as important as the prior steps. After the screed is properly installed, it is important to take preventative measures so as to protect the screed until the final floor is installed on it. This is done to prevent screed failures.
There are several ways to protect the floor screed, but primarily it is important to ensure that, once the screed is installed it stays undisturbed for at least 24-48 hours.