Very often during the repair process in a house or apartment it is not practical to dismantle the old wooden floor , however, the surface must be leveled 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. Plywood base is perfect for any further finishing, whether it is a laminate, parquet or solid wood. This foundation has many other advantages. Let's see how plywood is laid as a rough foundation.
Material benefits
Pressed sheet is an excellent material for rough and primary work on flooring. Sheets are inexpensive, they are convenient to transport, install. Plywood easily eliminates small differences in height on the floor. Often, plywood is laid before installing a parquet board, laminate and other finishing flooring.
Sheets reduce the time required for preparatory work before installing finish flooring. Plywood protects the underside of the finish against rotting - the material has the ability to “breathe”. This can be used when only a concrete screed is available as a rough floor.
Floors that are leveled with plywood can prevent wear or deformation of linoleum, carpet and other soft coatings, thereby extending the life of the unit. Using plywood, you can get a perfectly flat surface. The cost of laying plywood on the floor is very low, and the whole process is done by yourself.
Sheets are characterized by low weight, high hardness, resistance to various loads (including abrasion). The material has no odors; it has excellent sound and heat insulation characteristics. Plywood does not let heat through, but keeps it inside. Sheets are cut into large sizes - this allows you to reduce the number of joints in the process of laying plywood. Sheets are polished at the factory - this helps to prevent the sliding of plywood itself and other materials that are laid on them. Also, plywood does not allow moisture to pass at all, which makes it ideal for arranging floors in wet rooms, such as toilets, bathrooms and kitchens.
The material is eco-friendly, it is completely safe for humans, pets and children. An important advantage is its affordable 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 easily be explained by the fact that the material can be mounted on any basis.
disadvantages
The material has some drawbacks, but there are not many of them. Plywood is unstable to fire: it is a tree. Fire safety is very low. Also, the disadvantage can be considered the cost, when compared with similar chipboard and fiberboard. The floor, aligned with plywood, will at least slightly increase the height of the final structure. If the ceilings in the room are low, then this option is best not to use.
Which sheet to choose for the floor?
Do-it-yourself plywood laying requires the right selection of materials. Suitable plywood is the key to a quality result. The industry makes it in sheets, and it is classified according to the following set of characteristics. These are the methods and the presence of impregnation, the grade of plywood, the number of layers in the sheet, the presence of surface treatment, resistance to moisture.
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 should 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 the laminate. Thin materials will not be able to withstand the load. Thicker sheets are inconvenient in the process of working with them.
How many layers should be in a sheet? It does not matter for the arrangement of the floor. Experts recommend purchasing plywood sanded on both sides.
About varieties and types
Plywood is produced in four grades. Let's look at them. Knowing the varieties will help you when choosing:
- The material of the fourth grade has various defects on the coating. The surface is rough, there are holes from knots, since the most low-quality raw materials are used for production.
- Plywood of the third grade is higher in quality. On its surface there is less marriage, but it is.
- The second grade is distinguished by the presence of minor cracks, but the surface of such plywood is smooth.
- The highest quality material is considered to be 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 polished or unpolished. For the construction of rough floors or the leveling of existing ones, polished material is acquired on only one side.
About raw materials for production
Plywood sheets are made from hardwood as well as coniferous species of wood - most often manufacturers use birch and pine. The veneer is bonded with natural or synthetic resins. The top layer is treated with water repellents.
In addition to dividing by grades, plywood is classified by its level of resistance to moisture. So, the following brands are distinguished - FBA, FSF, FC.
For the arrangement of floors in bedrooms and other residential premises, where the humidity is not high, materials of the FC and FBA brands can be used. They are made on the basis of urea and albumin-casein glue. The plywood is environmentally 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 elevated. Then, after leveling the floor, laying of tiles on plywood on the floor can be carried out.
How to prepare plywood?
Before starting work, dry the material for about 2-3 weeks. Sheets need to be dried vertically. In this case, the room temperature should be slightly higher than the room temperature. When the drying is finished, the sheets are treated with antiseptic materials and the room is well ventilated. If it is necessary 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 installation work will be carried out.
Installation of plywood on an old wooden floor
In the process of installation on a wooden floor, the sheets can be fixed in a variety of ways - using screws, on liquid nails, on glue.
When laying plywood on glue, water-based adhesives, two-component glue, mounting adhesives, and also bustilate are used. But it is much preferable to fasten the sheets to the screws.
Tools and materials
In order to successfully install plywood sheets, the following tools and materials are required. So, you need plywood itself, a jigsaw, a building level, a tape measure, a pencil or a marker. There may also be a need for a grinding machine, roller, primer. Glue and sealing materials are being prepared.
Preliminary work
The floor is leveled with plywood only if the height differences are not more than ten millimeters. In this case, you need a substrate that compensates for bumps, as well as adhesive tape for gluing the joints of the material.
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 try to restore the floorboard if it has been attacked by mold or mildew.
The floors are cleaned of dust and dirt, they are twice passed along the surface with a primer on wood - this is necessary to increase adhesion. Then the base is dried for about 16 hours.
Marking and sawing
Plywood needs to be cut so that the number of joints is minimized, given the damper joints between sheets of 3-4 mm, as well as 8-10 mm between the sheet and the wall. This will avoid possible swelling of sheets in the future. During operation and temperature fluctuations of the workpiece will increase.
Sawing is carried out using a jigsaw. It is recommended that you carefully inspect the end sections of the plywood blanks - there should be no delamination. Over a large area, plywood is cut with a square of 50x50 cm or more. This technique will allow you to precisely level the floor and eliminate installation defects. The sawn blanks are numbered and by numbers create a layout of the blanks on the floor.
Styling process
There are features during the installation process. If necessary, the old coating is covered with a substrate where it is needed. Holes for fasteners are made with screws in advance, and then they are additionally countersunk. The self-tapping head should be sunk in the sheet.
Laying plywood under linoleum or another coating is carried out from niches, podiums, various ledges. Then the sheets are placed from the middle to the edges with a shift in the type of brickwork. Any gaps and gaps are filled with glue.
Lag mounting
If height differences on the basis of 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 there must be confidence that everything under it is in perfect order.
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, plywood sheets are prepared - the material is sawn, marking is done on paper, the elements are numbered.
Logs 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 using 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 a space between the guides - it is filled with any soundproofing material. There you can hide communications.
Next, the plywood squares are mounted according to the drawing. Fasteners are carried out on liquid nails, screws or glue.
Final work
Regardless of the device, laying the 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 polishing, the entire surface is varnished.
Installation of plywood on the screed
We examined 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 garbage will appear already on the finish floor.
Then the entire surface of the screed is covered with penetrating primers. The glue is applied with a curly spatula, and then the cut plywood is laid according to the numbers. So that the plywood sticks well to the floor, it is attracted with a dowel screw. Using a puncher, make a hole in the plywood and in the floor, and then hammer the dowel into the hole with a hammer.
The technology of laying plywood implies that the sheets are stacked at a distance from each other. So, between them it is necessary to retreat about 4 millimeters, and 1 centimeter from the wall. This is necessary to compensate for gaps due to changes in the geometry of plywood due to changes in climate or humidity.
If there are irregularities between the individual elements, then they are eliminated by a grinding machine. The gaps between the sheets are filled with glue. Slots can be repaired with gypsum-based finishing plaster. Next, grout the seams with a special grout mesh. Plaster close up and bumps on plywood.
Next, with a special reinforced adhesive tape, glue each seam on the plaster. Then you can safely proceed to the finishing of the base.
Recommendations for mounting sheets on concrete
On the screed you can put waterproof plywood brand FC. It contains wood veneer, which means that no harmful phenol was used in the production. This plywood is widely used in residential areas. Unpolished sheets must be sanded after laying. On the screed you can put plywood, which is processed only on one side. Thickness should vary from 1.2 to 1.5 centimeters.
The sheets are laid with an offset so that the joining of all four seams in one place does not work. Do not forget about waterproofing - the layer must be laid on the screed before installing the plywood. Sheets are recommended to be processed with linseed oil in two layers before laying.
It is not always necessary to cut the sheets into small pieces - especially for city apartments. This will only add work.
Plywood for linoleum
Some experts recommend using linoleum, not plywood, but the popular OSB. But the slabs are not perfectly even, with constant loads, part of the chip can peel off the sheet - this will certainly affect the evenness of the floor. Particleboard and fiberboard are also not suitable. Plywood is the most ideal option.
It is best to purchase sheets with a thickness of 12 millimeters or more. Thin materials up to 8 millimeters thick are suitable for a perfectly even subfloor. With a particularly uneven screed, they acquire thick plywood from 20 millimeters.
The sequence of operations, how to lay plywood on the floor, installation of plywood flooring - everything is described in detail above.
We install parquet and array on plywood
Many are sure that the rough basis for a 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 high-quality result. The subfloor will keep the finish from rapid wear.
As for the technology of laying parquet boards on plywood, the process is much better than if the base were concrete. Before installation, it is important to determine how the elements of the floorboard will be located.
Next, plywood sheets are prepared - a whole sheet is cut into squares of 50x50 centimeters. It is best to choose waterproof plywood. Installation is carried out on glue or without it. You can fasten the elements in a spread with compensation gaps. Additionally, the sheets are fixed with special fasteners. The thickness of the plywood should be 70 percent of the thickness of the parquet. Then, after the glue dries, you can proceed with the installation of the parquet board.
Laying a massive board on plywood differs only in that the array is a slightly different material. As for the installation of plywood, the process is similar.
Conclusion
So, we examined how to properly lay plywood on the floor. With this operation, you can easily and quickly level the surface and start installing flooring almost immediately. Usually plywood is used in order to then install laminate boards.