Reading time ≈ 3 minutes
Leveling the floor for subsequent coating requires precision and ensuring the entire surface is at the same level. Pouring a new screed in a room is not always convenient and quite expensive. An alternative option is a plywood floor, which will be installed on beams attached to the old screed. The thickness and width of the logs should be about 5 cm, and the length should be at least 2 m.
Attaching the log
In order for a do-it-yourself plywood floor on joists to be truly level, it is necessary to install the first level beam. The work should be carried out after finishing the finishing work of the walls and ceiling.
The installation of the logs is carried out not on the screed, but on the supporting scraps of boards or timber. This system allows you to level even very uneven surfaces with sudden changes or the presence of recesses or protrusions.
Subsequent lags are aligned relative to the previous element. This will allow you to maintain the set level throughout the room. Roofing felt should be used together with the underlying boards. Wood support elements can change shape with increased humidity or temperature changes, so additional layers will help maintain the resulting surface level and protect it from distortion.
To correctly level the floor with plywood, it is necessary to place the logs at a distance of approximately 50 cm. The distance from the walls should be small and be about 3 cm. The placement height is selected individually, but when fastening, you need to take into account both the thickness of the beams and the thickness of the supporting elements.
Therefore, it is necessary to use dowels that are at least 3-4 cm larger than the sum of these indicators. And to install plywood sheets, it is worth purchasing self-tapping screws 2-3 cm larger than the thickness of the purchased top covering.
Laying plywood
Plywood is laid on the floor only after it has been prepared. Use a jigsaw to cut out areas for pipes and corner projections of walls. The thickness of the purchased sheets must be at least 3 cm, since the resulting coating should not bend under the weight of a person and furniture installed in the room.
The plywood should be positioned in such a way that the joints of the sheets fall approximately in the middle of the joists. This will allow the work to be carried out correctly and ensure the reliability of the entire structure.
Roofing felt is placed between the joists and plywood sheets. This will avoid the “movement” of the coating and its deformation during subsequent use.
The location of the plywood relative to the joists should be transverse. Each sheet is attached not only along the edges, but also along the entire length of the support. It is advisable to avoid fixing in areas where people will walk.
Precaution will help avoid damage to the floor and guarantee its long-term safety. Detailed photos of the installation of the structure will allow you to see the process of assembling the plywood floor and the correct fixation of the sheets.
To understand how to make a plywood floor not only smooth, but also durable, it will be possible to clarify the layout of the sheets. The most correct thing is to shift the pieces: you should not carry out installation with a single connection line for all adjacent pairs of plywood. This can lead to distortion of the structure. A video describing the entire process of creating a high-quality and durable plywood floor will help you get acquainted with the intricacies of the work. And after proper installation, you can begin finishing the leveled surface with any floor covering.
DIY plywood floor installation video
by Challenger Living/ Photo by Lori Andrews
Do you dream of a beautiful, fashionable, but most importantly affordable and achievable floor covering? The Design Museum suggests considering the option of plywood, which, when compared with similar materials, is significantly superior in strength, and in addition, it looks very beautiful.
If we assume that plywood will act as the main floor covering, then you need to choose it by assessing the quality, and, no less important, the structure and pattern. We choose sheets with knots and streaks, they are the ones that will decorate your floor. The thickness of the slab must be at least 1.5 cm.
Photo: hindsvik.com
So, we offer just four steps that you need to take to get the floors of your dreams, such as you see in the photos presented.
Birch floors in the house of architect Michael Huber's
by Norris Architecture
Step One: Measurement
Carefully measure the room you are installing flooring in to determine exactly how many sheets of plywood you will need.
Make sure that the base surface is sufficiently level and prepare the sheathing for laying the sheets. There should be five to eight rows of timber per sheet of plywood.
Glossy plywood floor
Step two: cutting plywood
Choose a sheet size that is not too large so that it will fit well in your room. Carefully measure all parts and cut the pieces to the width you need.
Step Three: Glue and Nails
Leaving gaps between the wall and plywood from 10 to 15 mm, fix it with self-tapping screws, the second layer can be glued. By arranging the sheets in a checkerboard pattern, i.e. By overlapping the seams of the former, you achieve greater strength and your work will look more professional. By following these tips you can easily create the illusion of a real wooden floor.
Step Four: Sanding and Painting
The next stage is thorough sanding of the already assembled floor. And only after this the painstaking work of painting or varnishing begins, depending on what result you want to achieve.
You'll likely need to apply more than one coat of paint or varnish, and may have to sand in between if bubbles or uneven spots develop.
Sometimes you have to repeat the process up to five times, but believe me, these efforts will not be wasted when after some time (usually at least sixty hours), you get a smooth and shiny surface.
by Parallel Lines Studio
by Emily Jagoda
The combination of different sizes of plywood sheets gives a modern feel
by Churreria Photography
When repairing floors, many questions always arise. This is not surprising if you have such nuances, because the floor is a part of the house that is used almost around the clock. There are many options to make this part of the home comfortable, but you need to dwell in detail on how to build a plywood floor along the joists.
The process of laying a plywood floor at the stage of fastening to the joists.
This type of coating is perfect if you need to make insulation, but it is impossible to fill a cement-sand screed, and even if there are large uneven areas.
The bars that form the sheathing when installed are called lags. With their help, the surface in the room is leveled, and they also serve as a basis for attaching sheets. They can be made of metal or concrete, but the use of plywood requires the use of wooden blocks.
The construction of the floor will not be practical enough without lathing, since it gives the necessary rigidity to the sheets. Of course, there is a way to lay plywood without lathing, but this type of fastening can only be used if the room has a flat base. Without this, leveling the floor with plywood without joists will not be done well.
Laying joists on the street. First, they build a frame and connect the sections together. For logs, timber with a cross section of 50×100 mm is usually used. The rectangular shape is necessary so that the sheets can be joined on the wide side. In other words, if you don't have a support pad, attaching the sheet will be difficult.
Also, before the logs are installed, they must be treated with antifungal and fireproofing agents.
Pros and cons of choosing plywood
To the question: why is this particular material chosen to make an even coating indoors? The answer can only be given if you know its characteristics. The first positive quality is durability.
Compared to chipboard and USB boards, plywood will last much longer. The reason for this is the technology of its manufacture. Unlike other types of wood boards, plywood is glued with veneer, which gives it strength. Three types of adhesives are used for gluing veneer, two of them are moisture resistant, so plywood can withstand moisture for a long time without destruction or rotting.
When using this design, additional communications can be installed underneath it without resorting to cutting niches in the walls.
Plywood is stronger than other floor coverings and will last much longer The negative nuance is that this material is the most expensive of the entire group of wood-based panels. But the opinions of experts always agree on one thing: it is better to do it once and for a long time than to redo it due to the use of low-quality materials.
What plywood to use for floor joists
In order to make a plywood floor using joists with your own hands, you need to know what type of plywood to choose. If you consider that water leakage is possible in places where heating radiators are installed, you should purchase a moisture-resistant type. Second and third grade worksheets are perfect. It is also necessary to take into account the size of the sheets. Size 1525x1525 mm or 2500x1250 mm would be the ideal solution. These dimensions are chosen in order to cut the sheet into four parts and use them for installation. If the work is carried out in an apartment located in a multi-storey building, it will be problematic to lift large sheets.
Types of plywood
Today the industry produces 5 types of plywood, which are characterized by class.
- The first class is sheets that are sanded on both sides and have no flaws. They are used in the furniture industry;
- The second and third classes are sheets that are polished on one side, while the second remains untouched. This plywood is multi-purpose;
- The fourth and fifth grades are not sanded plywood. It is used for rough work.
The sheet's class can be identified by its seal, which is installed by the manufacturer.
Dimensions of unsanded birch plywood for flooring Plywood is also divided into three types based on water resistance. This factor depends on the type of glue used.
Sheet thickness
The thickness of the plywood for the floor along the joists is also taken into account in the calculations. Thin sheets will sag, which will lead to destruction, and thick sheets will not be very comfortable to work with. But there is a way out of this situation, and moreover, it will play into our hands. The minimum thickness of floor sheets should be 20 mm. For a more durable coating and ease of installation, sheets with a thickness of 10 - 12 mm are used, which are laid in two stands. This creates a seamless coating.
With this technology, the plywood floor will be durable and reliable.
Step by step guide
At the initial stage of work, it is necessary to dismantle the old coating, if any. If laying a plywood floor on joists is carried out on a screed, then all cracks and potholes on it must be repaired. Then the entire perimeter of the surface to be sewn needs to be primed. After preparing the base, it is necessary to lay a waterproofing film. To do this, you need to spread it over the entire surface with a slight overlap on the walls.
The next step is to install the logs. Initially, the lags must be fastened around the perimeter of the room. To do this, a joist level is marked on the wall. If you have a laser level, then there is no need for marking. With this device, alignment can be carried out at the installation site. All our logs will be installed on substrates made of pieces of plywood or wooden blocks or boards. The substrates are installed along the line of placement of each log at a distance of 50 - 60 cm from each other. After installation at the level of one log, the substrate is fixed to the floor using dowels. You also need to remember that when installing substrates, under each of them you need to adjust a piece of old linoleum or roofing felt.
Preparing lags for further laying of plywood It is important to note that the logs that are installed around the perimeter should not be in contact with the wall, that is, they are installed at a distance of 20 - 30 mm from each other. This placement is necessary for ventilation. After installing the logs around the perimeter, the remaining parts of the sheathing are installed. The distance between the floor joists under the plywood in our case is 70 cm. This distance was obtained by dividing the sheet in half. If sheets of other sizes are used, the distance between the logs will be different. For different cases it is 40 – 70 cm.
After installing the sheathing, insulation is laid between the joists. This can be polystyrene foam, mineral wool or expanded clay. As practice shows, the best option for the floor is mineral wool. It is not recommended to use polystyrene foam indoors due to harmful fumes, and expanded clay is less effective. Insulation mats should be cut 1 cm larger than the sheathing cells. When laying, such a mat will be tightly inserted between the sheathing bars.
After installing the insulation, the next step is to install a vapor barrier. It needs to be secured to the joists using a stapler.
Tools for work
To perform all the work efficiently, you will need a tool such as:
- Level;
- Roulette;
- Jigsaw;
- Miter saw;
- Hammer;
- Screwdriver.
As can be seen from the list, all work generally requires hand-held power tools.
Sizing adjustment
In most cases, when it comes to installing flooring, the problem that arises is the unevenness of the walls. This nuance does not allow installing parts of the coating exactly along the joists. To do this, you will need to trim each part along a line parallel to the wall.
We fasten the plywood sheet so that there is a small gap at the wall Marking and cutting are not carried out in a complicated manner. The sheet is placed against the wall so that the second edge lies strictly perpendicular to the joist. You will also need a rail that is aligned parallel to the wall. A cutting line is drawn along it. In this way, trimming is done around the entire perimeter. When adjusting the dimensions, it should be taken into account that there must be a gap between the wall and the covering.
Installation of the first layer
If it was initially decided that the structure would be laid in two layers, upon completion of all work with insulation and sheathing, you can begin laying the first layer - this is a subfloor made of plywood on joists. In order to do the installation correctly, you must first lay out the cut parts along the entire row.
They are attached to the joists using self-tapping screws. There should be a gap of 3 - 4 mm between the sheets. This gap must be sealed with sealant. This technological gap is required for expansion. The installation of the first row is carried out in this sequence.
It is worth noting that moisture-resistant plywood for the floor must be used for the first layer. To drill holes you need to use a tool such as a comfirmat. This attachment fits onto the drill and makes a hole for the screw heads. The screw head, when screwed in, will be recessed into the slab.
Second layer
When installing the second layer of flooring, all work is repeated, as when installing the rough one. An important point is that the sheets must be screwed together with mixed joints. For greater strength, the layers need to be glued together. This is done using construction glue. Installation of sheets must be carried out with the clean side. Thanks to this, upon completion of all work, a wooden covering is formed.
Loading...