Parquet laying technology

Recommendation points

• Floor screed laying
• Laying parquet on logs
• Laying parquet on a sub-floor

Before deciding to lay parquet, it is important to remember that wood is a “living” natural material that is influenced by such parameters as room humidity and temperature, therefore we recommend laying parquet only in those rooms where you can maintain normal humidity and temperature for it. mode! If the room is too dry, then in this case the parquet will lose moisture and shrink, losing its shape and size, which will ultimately lead to the formation of cracks between the parquet. If the room, on the other hand, is too damp, then the parquet will absorb moisture and increase in size, which can lead to the raising of the parquet planks (boat effect). Necessary parameters at which the parquet will maintain the optimum equilibrium moisture content of 8-12%:

• air temperature in the room +18 – +24 С
• relative humidity in the room 40-60%

During the heating season in winter, when the relative humidity of the air decreases, the air dries up due to central heating, we recommend the use of air humidifiers, which have a beneficial effect not only on the parquet floor, but also on the health of everyone around.

Floor screed laying

The option of laying parquet using a screed is necessary if, when measuring the subfloor, its unevenness is 2 cm or more. If the unevenness of the subfloor is less than 2 cm, then it is possible to use self-leveling mixtures.

Before laying the screed, the concrete floor is waterproofed to prevent the solution from seeping to the lower floor. To do this, use an ordinary thick polyethylene or special foil and reinforced polypropylene film. Along the edges, the film is brought out with some margin to the lower part of the wall for laying under the baseboard.

To dry the cement screed, a sufficiently long period is required, with a screed thickness of 3-5 cm – 4-6 weeks (in the first half of the period, the solution hardens, then dries up). With a screed thickness of more than 5 cm, the drying time increases by 1.5-2 times.

The next step is plywood flooring. A large sheet of plywood 10-18 mm thick is pre-sawn into squares (from 40×40 cm to 75×75 cm). This is necessary in order to relieve internal stress. The plywood thickness must be at least 2/3 of the parquet thickness (with a parquet thickness of 15 mm, the plywood thickness must be at least 12 mm, with a parquet thickness of 22 mm, the plywood thickness must be at least 18 mm). For good adhesion to the glue, the finished screed is first primed, and then a special glue is applied. After that, plywood is laid on the treated screed with a displacement of the joints so that the four corners do not converge at one point (“brickwork”) and leave 3-4 mm gaps between the sheets and about 10 mm leave a gap between the edges of the sheets and the wall, which at the final stage of installation, be sure to fill it with sealant. Plywood sheets are fastened either with screws (self-tapping screws) through pre-drilled holes. The heads of the screws (self-tapping screws) are “recessed” by 3-5 mm. After plywood is laid, a technological break of 2-3 days is required.

Before the next step – laying the parquet, the plywood must be sanded to eliminate the differences. Before laying the parquet, it must lie on the object for 3-5 days in order for it to accept the humidity and temperature parameters of the room. After that, they proceed directly to laying the parquet, for which parquet glue is applied to the plywood with a special spatula, on which the quality of fastening and material consumption depend. Then, in order to squeeze out excess glue and ensure a long and uniform adhesion of the parquet during the polymerization process, a special mechanical or pneumatic tool is used to shoot the parquet into the edge along the edge. Depending on the type of laying and a number of other reasons, sighting can be carried out from several pins (nails) into each bar to sighting through several bars.

The next stage – polishing the parquet and treating the entire surface with putty – is started after a technological break. This break is explained by the fact that in the process of gluing the parquet to the plywood, it receives excess moisture, and the parquet warps. Depending on the room humidity and temperature, the technological break is 5-7 days. Grinding the parquet after laying it is, first of all, necessary for 2 reasons: the inevitable contamination of the parquet and a slight deformation of some of the planks during the technological break. Parquet grinding is carried out by several types of equipment:

• a drum machine removes small defects (drops) and dirt;
• a surface grinder is used to refine the parquet to an absolutely even and perfect condition;
• under the radiators and near the walls, the parquet is sanded with special equipment for hard-to-reach places.

Due to the formation of microcracks in the inter-parquet joints after a technological break, it is necessary to putty the entire surface without exception. To make the color of the putty match the color of the parquet, the putty is prepared by mixing fine parquet dust obtained after polishing the parquet and a special liquid.

After polishing the parquet, they proceed to the most important and one of the most important stages – varnishing the parquet. When varnishing, there should be no drafts in the room, no air conditioners or humidifiers. First, a primer layer is applied to the parquet, which impregnates the pores of the wood with a special composition, preserves the natural color of the wood, if possible, and reduces the consumption of varnish during subsequent applications of finishing layers. Before the last finishing layer, intermediate polishing of the varnish with a special machine is required. This is necessary in order to remove the wood pile that rises after contact with the varnish. Manufacturers of varnishes recommend to apply 2-3 layers of finishing varnish after the priming layer of varnish, depending on the use of the room.

The very last stage is the installation of a parquet plinth, which, if necessary, masks the unevenness of the floor and walls near their junction, hides an additional cable or wires under it. Most often, the width of the plinth is selected depending on the height of the doorways and the room itself. The plinth is fastened, depending on its type, in different ways: with screws, special elements, nails, glued.

Laying parquet on logs

This option, in comparison with the option of laying parquet on a screed, excludes wet and dirty processes, and most importantly, this option saves valuable time spent on drying the screed. Also, this option allows you to lay any types of communications under the floor and makes it possible to improve sound and heat insulation by filling the space between the logs with insulation.

Lags are dry planed wooden bars of rectangular cross-section (50-55 mm x 70-100 mm), the moisture content of which should not exceed 12%. As a rule, the bars are impregnated with an antiseptic.

When installing logs on a concrete base, they are positioned so that they are perpendicular to the direction of the future coating, with an axial distance between adjacent logs of 25-30 cm.The logs are fastened using screws (self-tapping screws) and dowels at least 50 cm apart, heads screws (self-tapping screws) are “sunk” 3-4 mm below the level. After the logs are installed, they are leveled (the logs are cut and special wedges are attached to them).

In addition to the main traditional method of device lag, there is a method of device adjustable lag. Adjustable logs are the same dry planed bars of rectangular cross-section that have through threaded holes. Plastic rack bolts are screwed into these holes, rigidly attached to the base, which are subsequently adjusted with a special key, raising and lowering the logs, thereby leveling the floor.

After installing the logs, first one layer of plywood is laid on them, which is attached to the logs with screws (self-tapping screws), and then the second layer of plywood is attached to the glue and also to the screws (self-tapping screws). The heads of the screws (self-tapping screws) are “recessed” by 3-5 mm. The total thickness of plywood should not be less than 20 mm. After the plywood has been laid, it must be sanded to eliminate the drops and then, following the technology already familiar to us, to lay the parquet.

Laying parquet on a sub-floor

This option is perhaps the simplest and most economical. It does not take time to dry the screed, nor does it take time to install the lag. “Parquet cake” consisting of parquet glue on the sub-floor, plywood, parquet glue on plywood, parquet, putty and varnish is placed directly on the old wooden base. But at the same time, with obvious simplicity, this option is the most responsible.

Before laying parquet on a subfloor, it is necessary to carefully check its quality.

The gender must be:

• firmly and horizontally fixed on the logs, which must be well dried and soaked in an antiseptic;
• absolutely even;
• made of grooved boards (usually).

Gender should not:

• creak;
• have drops;
• move when walking.

If all the above requirements are met, the old floor can serve as the basis for laying parquet.

Waterproof plywood is laid on the old floor treated with glue, which is fixed with screws (self-tapping screws) at the rate of at least 5 pcs. per running meter and 9 pcs. per sheet. The heads of the screws (self-tapping screws), as in all previous cases, are “recessed” by 3-5 mm. After laying the plywood, lay the rest of the “parquet pie”.

Any of the above technologies for laying parquet is possible at the final stage of repair work (at the end of plastering, painting and other finishing works that are associated with high humidity and dirt). Before laying the parquet in the room, the following parameters are checked:

• air temperature (+18 – +24 С)
• relative humidity (40-60%)
• absolute humidity of walls and base (not higher than 4-6%)
• evenness and horizontalness of the base surface [screed, logs, old wooden floor] (permissible deviations of the base surface from the plane for a base of 2 m should not exceed 2 mm).

All these and other requirements are listed in building codes and regulations (SNiP 3.04.01-87; SNiP 2.03.13-88), as well as in the normative document VSN 9-94.