Make your own screed - correct proportions and price

by Staenis | 09/02/2021

Making your own screed: what are the right proportions?

If you want to install a new floor, you first need a solid surface. That is why a screed is placed between the filling layer and the floor finish. If you want to make screed yourself, you need to find out the correct composition of screed and have the exact proportions at hand. Find out everything you need to know to make your own screed.

Why install a screed?

To be able to place a finishing layer (tiles, parquet, etc.) on your floor, it must be evenly smooth. This is possible with a screed. A screed provides a strong foundation for your floor, protects utility pipes and contributes to a long life for your floor. Screed is mandatory, but also just a good idea. You can have your screed delivered ready-made, make it yourself, or have a screed silo delivered for larger quantities. You can even lay your screed yourself, even if you have no experience. Discover a handy DIY system.

Types of screed and their composition

Screed usually consists of sand, cement and water. Before you enthusiastically drive to the hardware store, you should know that there are different types of screed. So other combinations are possible. For example, in addition to cement-based screed (also known as traditional screed), there is also screed based on gypsum (anhydrite flow screed) and filling screed with an insulating effect (insulation screed). The best type of screed to use depends on how your floor is constructed and what the screed is expected to do. Discover quickly the most suitable floor structure for your new floor.

The composition of traditional screed (sand cement screed)

This time we are talking about the public's favourite among screeds: sand-cement screed. This cement-based screed can be used as a flat surface for all types of floor coverings such as tiles, laminate, parquet, etc. What type of cement do you need for sand-cement screed, and which type of sand is best to choose? What are the correct proportions? You can read it all later in this article. Budget tip: discover this handy DIY system before you employ a screeder.

Making screed: which cement to choose?

If you want to make sand cement screed, you can choose from different types of cement. Your chosen cement also determines the ultimate strength of the screed. Commonly used types of cement are Portland cement (CEM I) and Portland composite cement (CEM II). But blast furnace cement (CEM III) and composite cement (CEM V) are also contenders. Usually the cement type CEM II with a strength class of 32.5 is chosen. This type of cement can be easily worked with at temperatures between 10 and 20 degrees Celsius. At very low temperatures, cement types CEM I, CEM III A and CEM II are preferred. And at very high temperatures you go for CEM III B and CEM II, depending on the composition.

What strength class should your cement have?

The most common cement strength classes are 32.5, 42.5 and 52.5. If the temperature of the substrate or of the ambient air is between 10° Celsius and 25° Celsius, you choose the strength class based on the drying time you want to achieve. For normal hardening, choose strength class 32.5, for faster hardening, strength class 42.5 is more suitable. At a temperature above 25° Celsius, you will be fine with strength class 32.5. If the temperature is lower than 10° Celsius, you should look out for a strength class of 42.5.

Which sand to use for screed?

A common mistake when making screed is using sand that is too fine. For the production of traditional screed (sand cement), you should preferably use coarse river sand with a grain size of 04/07. Due to the coarse, round grain thickness, this sand is very easy to work with and you obtain a stronger screed with less shrinkage stress.

Making screed yourself: what is the right ratio between sand and cement?

It's not just the type of cement that determines the strength of your screed. The sand/cement ratio also plays an important role. What is the correct ratio between sand and cement? It depends. If there is a finishing layer on the screed, it is best to use one part cement to four to five parts sand. If no finishing layer is applied to the screed layer, which is the case, for example, when applying a filling layer, the ratio is one part cement to eight parts sand (stabilised). The ideal mixing ratio of sand and cement depends on the finishing layer. If in doubt, you can contact your supplier. Good to know: if you are going to make screed to use with the handy Staenis DIY system, you will use one part cement to five parts coarse river sand for the optimum result.

How much screed do I need?

With a classic sand-cement screed without underfloor heating, a minimum screed thickness of six cm is recommended. With a classic sand-cement screed with underfloor heating, or in a garage, it is best to use a minimum thickness of seven to eight cm. If you go for a screed thickness of six cm, you need 120 kg of screed per m². If you go for a screed thickness of seven cm, you should provide 140 kg per m². With a screed silo, the cement and sand are completely dry, so that the weight will be slightly lower per m³. Easily calculate online how much screed you need for your screed. It's the easy way to find out everything you need to place your screed yourself.

How to make your own screed

You can make small amounts of screed on a waterproof membrane. You can easily mix the sand and cement on it. For larger amounts of screed, it is better to use a concrete mixer. First, mix the sand and cement, according to the ratio discussed earlier. As soon as you have a homogeneous mass, add water with a sprayer until you get an earth-moist mixture. Adding water slowly with a sprayer ensures that you avoid lumps of cement when mixing in a concrete mixer. A good test: squeeze some mixture into a ball. If the ball falls apart, the mixture is still too dry and you need to add water.

Easily place your screed floor construction yourself

Do you already know who will lay your screed? Even if you have no experience, you can easily lay your screed floor construction yourself. With the Staenis DIY system, you can install your floor structure quickly and flat, without the risk of cracks. This saves you plenty of money in various situations, and you can also choose when you start the work. Also handy: if the screed work is not completely finished on one day, you can continue screeding at a later time without time pressure. Discover all the advantages of the Staenis DIY system.

Save with the Staenis DIY system

How does the Staenis DIY system work? The plastic Staenis grid consists of battens and height-adjustable legs, which you simply click together and adjust in height with a screwdriver. Your screed will then be placed in these grids. When damming and levelling, you can easily follow the height reference points of the Staenis grid. Interested? Use the Staenis floor construction tool to find out what the best floor construction is for your site. You can easily order your Staenis grid, the necessary fillers and the placement tool online.

Traditional screed is made with sand, cement and water. With the handy Staenis grid you can easily place your screed floor construction yourself. Screed for use with this DIY system is made according to a mixing ratio of five parts coarse river sand to one part cement. After mixing, add water until you get a good paste. Get acquainted with the Staenis self-build system and learn here how to start creating your floor structure.