What sand is best for floor screed: choosing sand for floors

This article discusses sand for floor screed. The topic is especially relevant because many people starting repairs wonder what sand should be chosen for making a floor screed. Let us try to understand and answer which sand is best for screed.

What Is Floor Screed For?

Repair work always includes many interconnected and sequential operations. Each operation is performed for a specific purpose. For example, floor screed is needed to:

• level floor irregularities;

• make the surface more rigid and durable;

• give the floor the required slope;

• improve heat and sound insulation properties;

• hide protruding engineering communications.

Moreover, floor screed is performed as a base for the final covering: tile, laminate or another material. Regardless of the purpose of this operation, the final covering must be strong, reliable and high quality to reduce the risk of cracks, bends or other defects. The reliability and durability of the floor depend on the quality of screed execution and the characteristics of the materials used to prepare the mortar.

The Role of Sand in Floor Screed

Sand makes up three quarters of the total mass of the final mortar. If cement is the binder, sand acts as the filler that determines the final functional qualities of the finished screed. These qualities are determined by a number of indicators, one of which is grade strength.

Grade strength is the indicator of a structure’s resistance to external mechanical effects. In other words, it is its stability. That is why choosing sand for screed must be approached responsibly and with understanding.

Choosing Sand for Screed

Sand used in construction work is divided into types, and each type is used in different areas with consideration of quality characteristics. In the same way, not every sand can be suitable for screed.

To obtain a high-quality screed, it is necessary to find a balance between a smooth coating surface and its strength. Screed strength depends on filler grain size, sand cleanliness and absence of unnecessary impurities. Unwashed sand with clay, silt or organic inclusions can worsen mortar quality and reduce finished screed strength.

Using artificial coarse-grained sand can lead to roughness on the screed surface, while fine-grained sand, because of dust-like particles, noticeably reduces construction quality.

As a rule, clean washed sand of a suitable fraction is chosen for screed. Washed quarry sand is often used: it has a fairly stable grain composition and, after washing, contains fewer clay and dust impurities. When choosing, it is important to consider not only the origin of the sand, but also its cleanliness, moisture content, fraction and the requirements of the specific mixture.