Aligning the floor with plywood on an old wooden floor: popular schemes + work tips

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Ludmila2208
Last update: February 2020

The wooden floor remains at the peak of popularity, as it is warm and durable. However, over time, under the influence of many factors, it can begin to sag. Agree, this can cause a lot of trouble, as well as spoil the appearance of the floor.

Based on this, the question arises how to properly level the wooden floor? We did a little research and figured out that leveling the floor with plywood is a great solution.

After reading this article, you will learn the main causes of gender irregularities, learn how to independently determine their size. In addition, you will learn what to look for when choosing plywood for alignment. And be sure to choose the option that suits you for leveling the floor.

Causes of roughness of the wooden floor

In the process of flooring, wooden logs are initially installed, which will serve as an even basis for flooring. Then a strong thread is pulled between them, which will serve as a beacon for installing the remaining lags. Extreme logs must be installed at the same level, otherwise the floor will have a slope.

If the distance between the lags is incorrectly calculated, for example, if the distance between the lags is too large, deflections in the flooring may appear.

Correct lag fixing
When installing the base, you need to pay attention to the correct fixing of the log, if the logs are not fastened enough, they can shrink, which will also lead to the deflection of the wood

When choosing wood, you need to pay attention to the degree of its moisture. The board should not be overdried or too damp.

The influence of air temperature and humidity in the room can also cause uneven floors. With increasing humidity, the wooden floor increases in size, and during drying it narrows. Over time, this can cause cracks between the boards.

If the wood is not treated with antiseptics and coatings, this also leads to deformation or, even, destruction of floor coverings.

When flooring, its hydro and thermal insulation. Properly selected waterproofing materials will ensure the dryness of the floor, and, therefore, will significantly affect the period of its high-quality operation.

Determination of the condition of the flooring

When assessing the condition of a wooden floor, it is very important to identify the extent of its damage, to conduct its inspection for the presence of fungus, rot, dips and creaks. If there is damage, they must be repaired.

If such defects were not found, then we further evaluate the value of the unevenness of the floor. Under the irregularities of the floor are meant tubercles or sagging.

To do this, you need to prepare: a bubble level of at least two meters in length, a rule (aluminum rail) or just a straight long rail.

Level measurement
The level must be applied with the butt to the floor and the unevenness of the floor should be measured, depending on the result, the leveling method

It is worth noting that the wood is not resistant to moisture, so “wet” leveling methods such as cement screed or special mixes for leveling floors will not work.

For leveling wooden floors, ordinary plywood is best suited. It is resistant to stress and is considered quite environmentally friendly material.

Choosing the Right Plywood

Plywood is a material that is produced by gluing veneer sheets in a perpendicular direction. The thickness of this material depends on the number of veneer layers.

Pros of using plywood for leveling wooden floors:

  • environmental friendliness of the material;
  • natural look;
  • reasonable cost;
  • strength;
  • moisture resistance;
  • a wide variety of species.

When choosing plywood, be sure to pay attention to its marking.

Plywood is different and marked depending on the production method:

  • FC - used in residential premises. High moisture resistance. The amount of harmful substances in the permissible norm. Suitable for children's rooms, living rooms, etc.
  • FBA - can be used in bedrooms, children's rooms. Low moisture resistance.
  • FSF - toxic substances are used in the production, therefore, use in residential premises is undesirable.
  • FB - the cost is higher due to the addition of a special varnish. High moisture resistance. Perfect for the bathroom and toilet.

There are four main grades of plywood.

The main grades of plywood
Grades of plywood differ only in cost and in appearance, while the strength is almost the same in all grades

First grade plywood has the highest cost. If the material will serve as a front coating, then it must be dry, calibrated - sanded from both sides, and its thickness will be strictly maintained throughout the plane. In addition, plywood that is used as a finishing floor should have a beautiful front side.

If it is planned to lay a tile, laminate or linoleum, the front side does not matter.

Popular plywood flooring patterns

The thickness of the plywood is selected based on a suitable leveling method. Next, we will talk about the most popular ways to level the floor with plywood and figure out how to carry out the leveling work yourself.

Option 1 - installing plywood on the base

It is used in case when the unevenness of the floor is insignificant (1-5 mm).
The leveling material is the substrate (polyethylene foam, interlining, etc.).

Plywood leveling underlay
First of all, on the floor under the plywood, you need to lay the substrate and, if necessary, glue together with tape

To level the floor in this way, you need to take plywood 8-10 mm thick. Before installing plywood on the floor, you need to stand in the room for at least two days.

If plywood will serve as the final floor covering, then to give an aesthetic appearance, it needs to be sawn into symmetrical squares.The main thing is to minimize material waste during cutting.

If, after leveling the floor, the plywood is covered with linoleum, tiles or other materials, then it can be laid in whole sheets without wasting time cutting.
Be sure to leave a gap between the plate and the wall of 5-10 mm - this is the thermal gap for expansion.

Scheme of fastening screws
Fasten plywood sheets to the floor with the help of self-tapping screws, pre-drilling holes in the plywood along the diameter of the body of the self-tapping screw and dig it under the hat

To fix plywood, you need 30-50 pieces of screws per 1 sq.m. After mounting the cap screws can be hidden under a thin layer of putty.

Installing plywood on the floor is the easiest and least time consuming way to level the wood floor.

Option 2 - Correction of minor irregularities

If, when assessing the size of the unevenness of the floor, a slope or a difference of up to 15 mm is detected, then two options can be used to level the floor.

A simple way to align

First you need to align the old flooring as much as possible. The protruding parts of the floor must be brought down using an ax or a plane. In places of deflection, we fix the lining with nails or self-tapping screws.

To level the floor in this way, plywood must be chosen with a larger thickness - from 16 mm. The substrate in this embodiment is also needed.

When mounting, do not forget about the indentation from the wall 5-10 mm. Plywood sheets are also fastened with self-tapping screws, having previously drilled holes in the plywood along the diameter of the body of the self-tapping screw and sweat under the hat.

Leveling with a belt support

This option is used if the floor slope needs to be aligned on the entire plane or partially in different planes.

This is the most time-consuming process, as it is necessary to even out the transition from the lowest floor to the highest.

First, you need to use a level to define a plane with a zero level. Next, a lath made of wooden beams is built.

The formation of the lathing of timber
The lath made of timber includes cells from longitudinal logs and cross members, the cell and the log pitch should be 40-45 cm in size

The cell should be built taking into account the fact that a plywood sheet will be attached to it. Therefore, before building the crate, it is necessary to mark the location of the plywood.

To achieve the same height, the lathing structure must be leveled with the help of pads of different thicknesses under the beam.

As the material for the linings, you can use plywood of different thicknesses, slats or bars. In addition, a gap of 30 mm between the slab and the wall must be left.

After alignment, the crate is attached to the floor with dowels. When this work is done, you can begin to fasten plywood to the crate. This is done, as in the previous methods, using self-tapping screws.

Option 3 - arrangement of a mini-lag

This method will be advisable to use if the differences are quite significant - up to 80 mm.

Mini-lags are wooden lining and slats. They are installed both along and across the boards.

Reiki on a wooden floor
For this method, you need to choose different forms of wooden slats for support, so that all plywood boards are set at the same level

Plywood for this method must be selected with a thickness of 16 mm or more. It should be noted right away that the method is not simple, since it requires separate calculations for each support element separately. Therefore, if you have doubts about your own strengths, it is better to turn to specialists for help.

Option 4 - crate of point supports

If the height differences on the floor are insignificant, then you can use a crate of point supports.

Fixing plywood to point supports
For this method, a grid is made of point pads for plywood, with a mesh size of 30-35 cm, after which plywood is attached to the point support

Plywood needs to be taken with a thickness of 12-14 mm. Compared to the crate method from mini-lag, this method is less reliable and stable, but it is faster and less expensive.

It can be used for small rooms.If the area of ​​the room is large, then it is better to use other methods of leveling the floor.

Tools required for work

All of the above work can be done with your own hands. And everyone can do it, the main thing is to prepare materials and tools for work in advance.

Here is a list of tools that will be required to work:

  • jigsaw or hand-held circular saw;
  • electric drill;
  • screwdriver;
  • hacksaw;
  • roulette or ruler;
  • level or rule;
  • plane;
  • ax;
  • hammer;
  • countersink;
  • putty knife;
  • sanding bar with sandpaper (grain 240, 320) for grinding.

When using power tools do not forget about safety precautions. In addition, do not neglect the arrangement of floor ventilation.

Plinth Installation
After carrying out all the finishing work and installing the baseboard, you need to drill holes in it with a diameter of 10 mm through a certain distance. This is done to ventilate the wooden floor.

Underground ventilation will protect the floor from dampness, the appearance of fungus, mold, which means it will extend its life.

Conclusions and useful video on the topic

Alignment of the old wooden floor with plywood with irregularities of 5-7 cm:

As you can see, there is nothing complicated in leveling a wooden floor with plywood. The main thing is to correctly determine the amount of unevenness of the coating and choose the appropriate method. With plywood, almost any base can be leveled. And compliance with the correct technology of work allows you to get a strong and reliable foundation for any flooring.

Have you ever had to level the wooden floor yourself with plywood? Please tell our readers how they used it and were there any difficulties during the work? Leave your comments, upload photos of the workflow, participate in the discussion. The communication unit is located under the article.

Was the article helpful?
Thanks for your feedback!
No (0)
Thanks for your feedback!
Yes (4)