Very often, during the repair process in a house or apartment, it is not advisable to dismantle the old wooden floor, but the surface must be leveled in order to perform further work. In such cases, you can make a rough plywood floor, thereby creating a perfectly flat area. Plywood floors are durable and resistant to various deformations. The plywood base is perfect for any further finish, be it laminate, parquet or solid wood. This foundation has many other advantages. Let's see how plywood is laid as a rough base.
Extruded sheet is an excellent material for rough and primary flooring work. Sheets are inexpensive, they are easy to transport, install. Plywood easily eliminates small height differences on the floor. Plywood is often laidbefore installing parquet, laminate and other floor finishes.
Sheets reduce the time required for preparatory work before installing floor finishes. Plywood well protects the underside of the finish coating from decay - the material has the ability to "breathe". This can be used when only a concrete screed is available as a subfloor.
Floors that are leveled with plywood help prevent wear or deformation of linoleum, carpet and other soft surfaces, thereby extending the life of the floor. Using plywood, you can get a perfectly flat surface. The price of laying plywood on the floor is very low, and the whole process is done by hand.
Sheets are characterized by low weight, high hardness, resistance to various loads (including abrasion). The material has no odors, has excellent sound and heat insulation characteristics. Plywood does not let heat through, but keeps it inside. Sheets are cut in large sizes - this allows you to reduce the number of joints in the process of laying plywood. The sheets are polished at the factory - this prevents slipping of the plywood itself and other materials that are laid on them. Plywood is also completely waterproof, making it ideal for floors in wet areas such as toilets, bathrooms and kitchens.
Eco-friendly material, completely safe for humans, pets and children. An important advantage isaffordable price. Leveling floors with plywood is most beneficial.
The process of laying plywood is simple, and this affects the timing of the work - they are minimal. This can be easily explained by the fact that the material can be mounted on any base.
The material has flaws, but not very many. Plywood is unstable to fire: it is wood. The level of fire safety is very low. Also, the disadvantage can be considered the cost when compared with similar chipboard and fiberboard. A floor leveled with plywood, at least a little, will increase the height of the final structure. If the ceilings in the room are low, then this option is better not to use.
Which sheet to choose for the floor?
Laying plywood with your own hands requires the right selection of materials. Suitable plywood is the key to a quality result. The industry produces it in sheets, and it is classified according to the following set of characteristics. These are the methods and the presence of impregnations, the type of plywood, the number of layers in the sheet, the presence of surface treatment, moisture resistance.
If a part of the structure made of plywood is hidden from view, then experts recommend choosing moisture-resistant options of the second or third grade. Sheets must have a thickness of not less than ten millimeters. But it is best to use sheets from 14 to 22 millimeters when laying plywood under a laminate. Thin materials will not be able to withstand the load. Thicker sheets are inconvenient to work with.
How many layers should a sheet have?It does not matter for the arrangement of the floor. Experts recommend purchasing plywood sanded on both sides.
About varieties and species
Plywood is produced in four grades. Let's take a look at them. Knowing the varieties will help in choosing:
- The material of the fourth grade has various defects on the coating. The surface is rough, there are holes from knots, since the lowest quality raw materials are used for production.
- Plywood of the third grade is higher in quality. There is less marriage on its surface, but it is there.
- The second grade is characterized by the presence of minor cracks, but the surface of such plywood is smooth.
- The highest quality material is the first grade. This is the most expensive plywood. The sheets are carefully sanded on each side, and there are no defects on each surface.
According to the processing method, plywood can be either sanded or unsanded. For the construction of rough floors or leveling existing ones, they acquire material polished on one side only.
About raw materials for production
Plywood sheets are made from hardwood as well as coniferous wood - most often manufacturers use birch and pine. The veneer is held together with natural or synthetic resins. The top layer is treated with water-repellent compounds.
In addition to dividing by grade, plywood is classified according to the level of resistance to moisture. So, the following brands are distinguished - FBA, FSF, FC.
For arranging floors inbedrooms and other residential areas where the humidity is low, materials of the FK and FBA brands can be used. They are made on the basis of carbamide and albumin-casein glue. Plywood is eco-friendly and at the same time resistant to moisture.
FSF is preferred for bathrooms, kitchens, corridors and is relevant in any other room where humidity is high. Then, after leveling the floor, the tiles can be laid on the plywood on the floor.
How to prepare plywood?
Before starting work, dry the material for about 2-3 weeks. Sheets should be dried vertically. In this case, the temperature in the room should be slightly higher than room temperature. When drying is completed, the sheets are treated with antiseptic materials and the room is well ventilated. If you need to increase the strength of the sheets, then several layers of acrylic varnish are applied to them.
Two days before the start of work with plywood, the material is brought into the room where the installation work will be carried out.
Mounting plywood on an old wooden floor
In the process of installation on a wooden floor, sheets can be fixed in a variety of ways - with self-tapping screws, on liquid nails, on glue.
When laying plywood on glue, water-based adhesives, two-component glue, assembly adhesives, and bustilat are used. But it is much more preferable to fix the sheets on self-tapping screws.
Tools and materials
In order for the installation of plywood sheets to be successful, the following tools and materials are required. So, you need plywood itself, a jigsaw, constructionlevel, tape measure, pencil or marker. There may also be a need for a grinder, roller, primer. Adhesive and sealing materials are being prepared.
The floor is leveled with plywood only if the height difference is no more than ten millimeters. In this case, you will need a substrate that compensates for irregularities, as well as adhesive tape for gluing material joints.
Next, it is important to inspect the general condition of the old floor. If there are creaking floorboards, then they are strengthened. Rotten elements or damp - change. Do not attempt to repair a floorboard that has been attacked by mold or mildew.
The floors are cleaned of dust and dirt, they are twice passed over the surface with a primer on wood - this is necessary to increase adhesion. Next, the base is dried for about 16 hours.
Marking and sawing
Plywood should be cut in such a way that the number of joints is minimized, taking into account the damper seams between sheets of 3-4 mm, and also 8-10 mm between the sheet and the wall. This will avoid possible swelling of the sheets in the future. In the process of operation and temperature fluctuations, the workpiece will increase.
Sawing is carried out using a jigsaw. It is recommended to carefully inspect the end sections of plywood blanks - there should not be delaminations. On a large area, plywood is cut into a square of 50x50 cm or more. This technique will accurately level the floor and eliminate installation defects. The sawn blanks are numbered and the layout is created by numbersblanks on the floor.
There are peculiarities in the installation process. If necessary, the old coating is covered with a substrate where it is needed. Holes for fasteners are made in advance with self-tapping screws, and then they are additionally countersinked. The head of the self-tapping screw should be recessed into the sheet.
Laying plywood under linoleum or other coating is carried out from niches, podiums, various ledges. Then the sheets are arranged from the middle to the edges with a shift like brickwork. Any cracks and gaps are filled with glue.
Mounting on logs
If the height difference on the base is more than 1 centimeter, then it is recommended to lay plywood on boards or logs. The latter can be installed on the old floor, but you must be sure that everything is in perfect order under it.
The old floor is cleaned of debris and dust. In this case, you need to pay enough attention to the gaps between the floorboards. If the cracks are large, then they are filled with glue or sealant. At the same time, sheets of plywood are being prepared - the material is sawn, markings are made on paper, the elements are numbered.
Lags are guide boards for leveling the floor. These are slats, the length of which is approximately 1.5-2 meters, the cross section of the board is 40x15 millimeters. Logs are attached to the floorboards with dowels or self-tapping screws. They are set so that their upper borders give a single plane, and the slats give a crate. There will be space between the guides - it is filled with any soundproofing material. You can also hide communications there.
Further, the plywood squares are mounted according to the drawing. Fixing is carried outon liquid nails, self-tapping screws or glue.
Regardless of the device, laying plywood on the floor with your own hands also implies a finishing operation. It comes down to processing the joints of the sheets with emery to smooth out irregularities. After sanding, the entire surface is varnished.
Mounting plywood on a coupler
We looked at the features of mounting on a wooden floor. But in most apartments the floors are concrete. Let's look at the features of laying plywood under the screed.
Before starting work, the surface is also thoroughly cleaned. It will be very good if the surface is cleaned not with a broom, but with a vacuum cleaner. Debris, sand, as well as dust - all this will significantly impair the adhesion of the adhesive to the floor. In addition, through the glue, irregularities in the form of debris will already appear on the finish flooring.
Then the entire surface of the screed is covered with penetrating primers. The glue is applied with a figured spatula, and then the cut plywood is laid by numbers. In order for the plywood to stick well to the floor, it is attracted with a dowel-screw. Using a perforator, a hole is made in the plywood and in the floor, and then a dowel is hammered into the hole with a hammer.
Plywood laying technology implies that the sheets are stacked at a distance from each other. So, between them it is necessary to retreat about 4 millimeters, and from the wall - 1 centimeter. This is necessary to compensate for gaps due to changes in the geometry of the plywood due to changes in climate or humidity.
If between separate elementsthere are irregularities, then they are eliminated with a grinding machine. The gaps between the sheets are filled with glue. Cracks can be sealed with gypsum-based finishing plaster. Next, the seams are rubbed with a special grout mesh. Irregularities on plywood are also covered with plaster.
Further, each seam on the plaster is glued with a special reinforced adhesive tape. Then you can safely proceed to the finishing of the base.
Recommendations for mounting sheets on concrete
You can put waterproof plywood brand FK on the screed. It contains wood veneer, which means that no harmful phenol was used in the production. This plywood is widely used in residential areas. Unsanded sheets should be sanded after laying. You can put plywood on the screed, which is processed on only one side. The thickness should vary from 1.2 to 1.5 centimeters.
Sheets are placed with an offset so that all four seams cannot be joined in one place. Do not forget about waterproofing - the layer must be laid on the screed before installing plywood. Sheets are recommended to be treated with drying oil in two layers before laying.
It is not always necessary to cut sheets into small pieces - especially for city apartments. This will only add more work.
Plywood under linoleum
Some experts recommend not using plywood for linoleum, but the popular OSB. But the plates are not perfectly even, under constant loads, part of the chips can peel off from the sheet - this will certainly affect the evenness of the floor. Chipboard and fiberboard are also not suitable. Plywood- the most ideal option.
It is best to purchase sheets with a thickness of 12 millimeters or more. For a perfectly flat subfloor, thin materials up to 8 millimeters thick are suitable. With a particularly uneven screed, get thick plywood from 20 millimeters.
The sequence of operations, how to lay plywood on the floor, install the plywood floor - everything is described in detail above.
Installing parquet and array on plywood
Many people are sure that the rough base for the parquet floor is a waste of money. However, it is not. Experts with experience are sure that with the help of plywood you can get a quality result. The subfloor will keep the finished base from rapid wear.
As for the technology of laying parquet boards on plywood, the process goes much better than if the base was concrete. Before installation, it is important to determine how the parquet board elements will be located.
Next, plywood sheets are prepared - a single sheet is cut into squares of 50x50 centimeters. It is best to choose waterproof plywood. Installation is carried out with or without glue. Elements can be fastened randomly with compensation gaps. Additionally, the sheets are fixed with special fasteners. The plywood thickness should be 70 percent of the parquet thickness. Further, after the glue has dried, you can proceed with the installation of the parquet board.
Laying a solid board on plywood differs only in that the solid wood is a slightly different material. As for the installation of plywood, the process is similar.
So, we have looked at how to properly lay plywood on the floor. With this operation, you can easily and quickly level the surface and almost immediately begin to install the floor covering. Usually plywood is used in order to then install laminate boards.