Installation of floors using dry technology – how to do it yourself

Recommendation points

• The flooring process can be divided into such stages
• Floor surface preparation
• Installation of a moisture-proof layer
• Providing sound insulation
• Laying bulk material
• Laying gypsum fiber sheets
• Dry screed ready

Traditionally, we begin to equip the floor by starting to make a screed from concrete mortar or cement-sand mortar, this process is called wet. But there is also dry technology, which is not very common, and economically viable..

This method of flooring is used in the construction of high-rise buildings, as well as in the repair of old buildings. Of course, this technology has been known for a long time and became widespread 40 years ago..

The essence of this technology is that a very thick layer of dry backfill is applied to the floor slabs, then a durable sheet material is applied, and then the finishing floor is laid. The number of such layers and materials may vary depending on the characteristics of the floor and the necessary requirements for its quality. These floors can be installed on log floors.

The main feature when installing floors using dry technology is to avoid the processes associated with concrete work. This saves both time and labor intensity, it becomes possible to lay communication lines in the screed, to provide sound insulation and thermal insulation.

It is advisable to use such floors in the following cases: when installing wooden heated floors; in winter, when construction work is difficult to carry out; when the installation of the sub-floor needs to be carried out very quickly; when renovating old buildings.

Before starting work on the installation of the floor, it is necessary that all work begins after the end of finishing, sanitary-technical, electromechanical work, as well as the heating and water supply systems must work.

The flooring process can be divided into such stages

Floor surface preparation

First, the old floor is removed, the gaps between the floor slabs, between the overlap and the walls are closed with a cement-sand mortar, the assembly potholes and grooves are cleaned of construction debris.

Installation of a moisture-proof layer

All dry floors are afraid of moisture, and serious leaks can simply destroy it – we are preparing a moisture-proof layer. You need to know that when installing such a floor, in the event of a serious leak, the slabs swell and the front covering will deteriorate, therefore a moisture-proof layer is always laid under the base of the floor, which protects the backfill from moisture. The question arises, where does the moisture come from? It can come from the room below, and it can also stand out from the concrete floor.

A hydraulic or laser level marks the surface of the backfill on the wall, and a protective coating is made of the film. The film is applied in such a way that near the walls it rises to a dry screed. For a reinforced concrete floor, a regular polyethylene film with a thickness of 200-250 microns is used, and for a wooden floor – glassine or bituminous paper, or a universal or modern vapor barrier.

Providing sound insulation

Along the walls along the entire perimeter of the floor, they try to get or leave a gap of 8-10 mm wide, this is necessary to exclude sound gaps, as well as to avoid curvature of the finished floor. In the form of an edge band of glass or mineral wool, polyethylene foam, sound insulation is laid.

Laying bulk material

The next stage consists in laying bulk material, which creates a flat surface for the floor and enhances the level of thermal insulation. For such a backfill, materials are used that give minimal sediment, high porosity, have a granular composition, low hygroscopicity and mineral composition, to ensure fire safety. Such materials can be fine-grained slag, silica and quartz sand, production screening of expanded clay, expanded perlite sand and other inorganic dry bulk materials..

The standard backfill thickness can be 30-50 mm, but there are cases of greater thickness. If the layer thickness exceeds 60 mm, then the dry screed must be reinforced with an additional layer of plates. Of course, the thickness of the backfill depends directly on the quality of the floor slabs, as well as the availability of communications or other equipment. If the surface does not require leveling, then instead of backfilling, you can use plates of extruded polystyrene foam.

Also, such plates are used in addition to the backfill, which guarantees additional sound insulation and heat protection, since the backfill itself does not do this. When backfilling, an edge tape is placed along the walls, and it is controlled that the slabs fit tightly to each other.

Laying gypsum fiber sheets

So, if there are heat-insulating plates on the surface, work starts from the opposite wall, and if the backfill insulation – from the door. It is recommended to make a dry screed from gypsum fibrous sheets of various sizes, from chipboard, waterproof plywood, asbestos-cement sheets, tongue-and-groove chipboard with an oriented structure. The latest novelty on the construction market was the appearance of two interconnected gypsum-fiber sheets, as well as combined elements with an expanded polystyrene layer additionally.

What type of laying sheets you use will determine what kind of laying technology you will use. Chipboard, plywood, gypsum fiber sheets and other sheet materials, depending on the thickness, are laid in one or more layers, connecting them together with nails or glue, and the resulting seams are putty and polished. The outer side of the screed is covered with bituminous waterproofing.

Dry screed ready

You should be aware that a floor laid using this technology is able to withstand the loads that concrete floors can also withstand. The price for such a floor will be approximately $ 10 m², film and cable electric heaters can be used on it.