Rough plank floor. Subfloor in a wooden house

Before installing the subfloor in wooden house You need to familiarize yourself with all the design nuances with your own hands. In what ways can they be laid depending on the architectural characteristics of the buildings? What installation requirements must be observed? Read more below.

When choosing a specific option, you need to take into account the purpose of the building, number of storeys, materials and technologies used.

General requirements for subfloors

Regardless of the type of structure, building codes require the following activities.

Fire protection. All fire-retardant materials are divided into two groups according to their resistance to fire. The first group is used for wooden houses With stove heating. There is a wide range of solutions available; impregnation is done with a pneumatic spray gun or paint brushes. A prerequisite is that the lumber must be dry. The number of layers is determined taking into account the purpose of the wood.

Protection from putrefactive processes and biological damage to wood. It is recommended to carry out the work using effective antiseptics; all of them reliably protect lumber from premature destruction due to high humidity. The disadvantage of such materials is the release of chemical compounds into the air. True, the concentration is considered safe for residents. For those who do not want to risk their health, there is a completely safe way to protect lumber - impregnation with natural technical oils.

Important. All impregnations and treatments must be carried out before laying the lumber, and not after. One more nuance - great attention should be paid to the ends, they are most susceptible to moisture. Fresh dust and ends are subject to additional impregnation.

It is mandatory to have vents to ensure natural ventilation of wooden structures. No impregnation will save the wood if it is not constantly ventilated. The parameters of the vents are specified in SNiP 01/31/2003; the diameter and location of the holes depends on the area and height of the underground. Protection of the underground from penetration of rodents into the openings is done with metal gratings; the geometry of the vents is not regulated.

Practical advice. Be sure to check the effectiveness of natural ventilation; if it is not there, the subfloors will not last the expected amount of time. To check, you can use smoke or open fire. In the absence of visible air flow measures should be taken immediately to improve the efficiency of natural ventilation.

Fulfillment of requirements building codes guarantees long and safe operation floor coverings. As an example, we will look at two methods for arranging subfloors.

Subfloors on load-bearing wooden beams

The beams are laid on the foundation strip or strapping beam. There is no fundamental difference between the two methods; it all depends on the chosen method of building a house. A prerequisite is that there must be reliable waterproofing between wooden structures and concrete elements; most often, two layers of roofing material are used. This is the most cheap material, providing reliable water protection. In addition, the timber must be treated with any antiseptics.

The beam must lie strictly in one plane; installation is done using a level. Round logs need to be cut off on both sides with an axe.

If you have no experience working with an ax, it is better to purchase ready-made material. But keep in mind that in terms of strength it will be inferior to hewn round timber, but in cost it is significantly higher. The subfloor is attached to the lower base of the beams; the flooring will be made of OSB. But if you wish, you can use any available materials, and not just wooden ones.

Step 1. Unscrew the beam fastenings. The bars are screwed to the frame using metal corners and long screws. The subfloor is installed only on pre-exposed beams; therefore, their dismantling is required.

Step 2. Carefully remove the beam from the mounting slot and turn it face down.

Step 3. Attach the OSB strip to the bottom of the beam with self-tapping screws or ordinary nails. The width of the strip should be 10–15 cm greater than the width of the flat area of ​​the beam.

Important. The length of the screws should be ≈ 70% greater than the thickness of the plate, otherwise the fixation will not be reliable. This rule applies to all cases of fixing structures to each other.

When tightening the screws, press the drill with great force; the plate should not lift. When screwing in, inexperienced builders do not press the screws with sufficient force; the screw rotates slightly in the slab, causing a gap to appear between it and the beam. This greatly worsens the parameters of the subfloor.

Using the same technology, attach the sheets to all beams.

Step 4. Place all dismantled beams in place, secure them with metal squares and self-tapping screws. Check the position again and, if necessary, adjust them with shims of different thicknesses. Never use lumber for underlays; they will certainly sag over time, which will disrupt the horizontality of the final floor covering. For linings, use durable, moisture-resistant ones. Construction Materials. Another important condition– the dimensions must be equal to or larger than the beam areas, which will allow the loads to be evenly distributed.

Step 5. Place the pieces of OSB in the prepared areas. When preparing sheets there is no need to remove exact dimensions, small gaps not only simplify the installation process, but also improve natural ventilation subfloor. In this way, by the way, you can save lumber.

Practical advice. Never walk on subfloor, it is not designed to carry that much weight. When laying the last row, you should walk on the beams. If you wish, you can foam the joints of sheets and beams, but this operation is not considered mandatory. We have already mentioned that wood must be ventilated. As for the increase in heat losses, it is insignificant.

Step 6. Lay a vapor barrier, never use ordinary polyethylene film for this purpose high pressure. The fact is that it does not allow steam to pass through, and as a result, water will always accumulate in the heat insulator; it is in the insulation layer that the condensation point is located. High humidity significantly reduces the heat-saving properties of mineral wool and has a very negative effect on wooden structures. Moisture must be constantly removed from the insulating layer, and only modern membranes can provide this.

Fix the vapor barrier to the beams with a stapler, the overlap of the layers is at least 10 cm, the joints should be carefully sealed with tape.

Step 7 Lay a layer of thermal insulation. For these purposes, you can use rolled and pressed mineral wool or. It is advisable to use mineral wool. Why?

1. Mineral wool does not burn. Due to these fire resistance characteristics, it is also used as a fire barrier.
2. The material is completely safe. Mineral wool is made from basalt, which is a natural glass of volcanic origin.
3. Basalt wool is not afraid of rodents, which is very important for wooden houses.

Pressed and rolled cotton wool is produced standard sizes, it is recommended to take them into account during the installation of beams. The width of the wool is 60 cm, the distance between the beams is recommended ≈ 55–58 cm. Due to these dimensions, a tight fit of the insulation to the structures is ensured, reducing heat losses, the indoor microclimate improves. In addition, there is no need to cut the sheets, which speeds up work and reduces waste.

The thickness of the insulation is at least 10 cm. Make the second layer offset to cover the joints. If a wooden house is built in a cold climate zone, then the insulation layer must be at least 15 cm thick.

Step 8 Cover the thermal insulation with a waterproof membrane. The technology for installing it is no different from the algorithm for installing a vapor barrier membrane.

Step 9 Nail slats approximately 2 cm thick to the beams; they will serve as joists.

Practical advice. Professional builders strongly do not recommend laying the floor directly over the beams. Ventilation is provided by the bars finishing coating, and it is needed regardless of the type of floor.

Further work depend on the technology and finishing materials you choose.

Installation of subfloors along joists

These options are used in wooden buildings, being built according to the most modern technologies. The floor will be made of glued moisture-resistant plywood 2 cm thick, the flooring method will be on joists.

Step 1. Measure 120 cm on one side of the floor, this is the length of standard sheets. If the plywood is tenoned, then the measurements must be taken very carefully, otherwise the tenons will not fit into the groove in one line. The use of tenon plywood eliminates the appearance of drafts, which is very important for high-quality installation of the finishing surface. For correct installation sheets, use coated thread.

Using a nail with thread (left) and coated thread (right) to mark

If the house is very large and the length of the thread is not enough, then you should first use a rope. Drive nails into the outer joists, taking into account the dimensions of the plywood, and stretch the rope between them. Taking into account the length of the coated rope, drive an additional one or more nails along the line into the joists taut rope. Now the marks can be applied without fear, they will all be exactly on the same line.

Step 2. Lay out the first row of plywood on the joists, while first marking the excess width.

Important. The thickness of the plywood is selected taking into account the distance between the joists and the maximum load on the floor. This means that the sheets can be not only two centimeters thick.

Step 3. Apply liquid nails to the joists. They have several advantages: they significantly speed up the construction process, the subfloor will never creak, and they guarantee sufficient fixation strength. In addition, liquid nails allow you to easily correct small errors. The glue should be applied in the middle of the joist. If the edge of the sheet lies in the middle of the joist, then the glue, accordingly, is applied only to a narrow section of the element.

Step 4. Turn over the sheet of plywood and attach it with ordinary nails. According to existing rules the distance between them should be within ten centimeters around the perimeter of the building, and the length should be 6–7 cm. The distance between hardware along the joists is 15 cm, inside the building ≈30 cm.

Important. Plywood can expand due to increased humidity; leave a gap of a few millimeters between the sheets. It is convenient to use nails as a template; insert them between the sheets, and remove them after fixing. There are situations when the edges of the sheet do not fall in the middle of the joist. In these cases, the material must be carefully trimmed taking into account the requirements described above.

If the sheets fall on ventilation holes or other engineering Communication, then measure their dimensions and exact location, then, using a manual electric circular saw, cut off the excess.

It is much easier and faster to hammer nails with a pneumatic hammer. How to quickly do this manually?

1. Put in left hand several nails, they are all mixed, the heads and points are located on different sides.
2. With your right hand, grab the nails by the heads, carefully pull them out, turn them over into the desired position and place them with the rest. Now all the caps are located on top.
3. Use your thumb to pry up the nails one at a time, grab them with your index and middle fingers and place them with the tip on a sheet of plywood. Do not forget that you need to drive the nails in at a slight angle to the plywood veneer, otherwise it may crack.
4. Hit the nail with the first light blow of the hammer, and with the second strong blow, drive it in until it stops.

You can be sure that after a few minutes of training, the speed of driving nails will not differ from that of a machine, and the quality will not suffer.

Step 5. Cut the last sheet to size and secure it to the joists.

The rows of joints should be staggered; for this, the next one must be started with half a sheet or the remaining segment. Joining tongue and groove plywood requires considerable effort. To do this, use a piece of wood, apply it to the edge and with strong blows use a hammer to connect the tenon and groove. Apply blows alternately on each side, do not allow the sheets to distort, remember the damper gaps.

Step 6. Mark the edges of the sheets protruding beyond the contour of the joists. It is better to use coated thread; carefully cut off the excess along the line.

Important. Be very careful when working with electric woodworking tools. Injuries from them are complex and can cause disability. Tools must be in good working order and adjusted, and cutting devices must be sharp. Never remove factory guards.

Step 7 Proceed to seal the opposite edge of the floor. Work will go It’s faster if you don’t take the dimensions of each sheet, but attach whole ones. Then you should measure the width of the protruding pieces and transfer the lines to the front surface. Using an electric saw, cut off the excess according to the marks.

For the final covering of the subfloor, you can use most of the previously obtained sections, due to this the estimated cost will be reduced wooden house.

How to avoid mistakes during subfloor construction

The main advice is don’t try to simplify it yourself. existing technologies. Only an amateur thinks that he is smarter than everyone else and can do the work faster and cheaper. All rules were developed taking into account many years of construction experience; each technological operation has its own specific purpose. An incorrectly laid subfloor causes sagging and creaking.

1. Before starting work, check the position of the joists. The distance between the lags should not exceed 58 cm, this will allow the insulation to be tightly laid.

   

2. There is no need to skimp on the size of the beams. During the operation of the house, it becomes necessary to install heavy furniture; the likelihood of increased loads should be foreseen in advance.

   

3. In the place of masonry brick oven always reduce the distance between joists or beams. During construction, use only healthy lumber without natural diseases and defects.
4. Boards for making subfloors must have low performance relative humidity. If the subfloor is laid before the roof of the house is erected, then work should only be done in good weather. Overmoistened boards not only quickly lose their original load-bearing characteristics, but also decrease in size during drying. As a result, the fastening is weakened, and the floor bends and creaks when walking. It is very difficult to fix the problems; often you have to completely dismantle the coating.

   

5. If the subfloor is located between the floors of a wooden house, then the cranial bars should be placed along the beams. Packed across, they reduce the height of the room.

   

6. When installing membrane vapor or waterproofing, carefully read the instructions. The material indicates which side it should face towards the insulation. The fact is that steam can only escape in one direction; if the fabric is laid incorrectly, then there will be no positive effect. As a result, the subfloor will be constantly wet, and the effectiveness of thermal insulation will noticeably deteriorate.

   

7. Do not skimp on the vapor barrier, cover the joists as well; attempts to cut the roll into small pieces always give a negative result. In terms of footage, the savings are negligible, and Negative consequences noticeable.

   

8. Always leave a ventilation gap between the rough and finished flooring. At the same time, consider the location of the air outlets.

   

9. Practitioners recommend covering the ground under the floor of the first floor plastic film or roofing felt. Due to this, the amount of evaporated moisture is reduced, and the operating conditions of the building are significantly improved.
10. It is recommended to install a warm subfloor only under the living quarters of the first floor. There is nothing to save in unheated ones; an expensive complex cake is not needed.

Unconditional compliance with building standards guarantees that no unpleasant situations will arise during the operation of wooden houses. In all cases, eliminating the consequences of technology violations is much more expensive than complying with the rules for constructing subfloors.

Before you start laying the final coating, you need to take care of the rough coating. This rule should never be neglected, because otherwise you risk your entire repair. Remaking the flooring and the floors themselves will require even more effort, expense and time. In addition, such a complex event can cause damage to the entire interior of an apartment or house. So experts recommend taking a close look at the subfloor issue once and forgetting about it for many years.

There are two main ways to create a subfloor, which are divided according to the method and materials used: wet and dry. For wet, concrete or concrete expanded clay is used, and for dry, installation on joists is used.

DIY concrete subfloor

This option is especially popular in standard city apartments, but if desired, it can also be used to furnish a private home. The only question is the foundation.

First you need to create high-quality waterproofing. This can be done using a special film of increased strength. If we're talking about about renovations in an apartment on the second and higher floors, we recommend that you pay special attention to insulation. Your manipulations with the floor can cause leaks and affect the repairs of the neighbors below. So be very careful when installing the film. Along the perimeter of the apartment it needs to be supplemented with penoflex with a thickness of 0.5 - 1 centimeter.

The next layer of the subfloor is responsible for the thermal insulation of the room. Previously, polystyrene foam was predominantly used as a material, but in Lately penofol, consisting of two layers at once, with very good characteristics. The foil layer reflects heat and prevents it from leaving the room, and the polyethylene foam itself is responsible for thermal insulation. Whatever material you choose, it must also be covered with a layer of waterproofing film.

Next important stage- this is the pouring of the floor with concrete or concrete expanded clay. But you can’t just pour the solution onto the future subfloor. The thing is that this layer will not be able to level itself. That is why, before pouring, special beacons are installed, which will become the basis for leveling the floor. All beacons must be level. Only in this case will you be able to get a beautiful and smooth subfloor as a result.

If you want to increase sound insulation, as well as thermal insulation, then pay attention to concrete expanded clay. This material has excellent properties and outperforms conventional concrete in many respects.

Having mixed the solution and distributed it over the floor, carefully level it using the rule, placing the tool on the beacons. Remove excess solution, then leave the coating until completely dry. Your subfloor is ready.

DIY wooden subfloor

To make a subfloor out of wood, you will need some kind of base. If the house already has concrete, then logs can also be laid on it. Just make sure that the concrete screed is level and has no differences in height. Otherwise, your floor will turn out crooked and will creak. Experts do not recommend using wooden blocks as a support for joists in excavation areas. The problem is that over time the wood will shrink and the joists will lose their stability. And your floors will sag and creak.

To avoid this, you need to be careful preparatory stage. So, to begin with, the concrete base is leveled using a small layer of screed. The amount of solution is determined by the height difference in the room. After this, leave the resulting base until the solution dries completely.

The next point is laying the waterproofing film, all joints of which must be taped. On top of it, in the place where the logs will be laid, we lay a special soundproofing layer. Foamed polyethylene or cork material is usually used. Without this layer, the floors in your home will make noise with every step.

Now it's time to deal with the lags. But for this you will need timber. Professionals recommend not skimping on joists and using edged boards High Quality. Installation will take you much less time and effort, and your own subfloor will turn out much more impressive and faster. To install the subfloor you will also need edged board 25 mm x 100 mm. It can be used not only for installing joists, but also for installing roof sheathing and other general construction work.

The logs themselves are installed on a pre-prepared base so that the layer of soundproofing lining is strictly under them. The height and slope of the joists must be checked with a level.

Now they need to be attached to the base of the floor using corners so that the logs do not move anywhere and serve as the basis for the next layer.

As soon as all the logs are firmly fixed, insulation is laid between them. In no case should it go onto the logs themselves, only occupy all the free space between them.

A floorboard or plywood is laid on top of the joists. This is what the subfloor itself will look like. Working with plywood is much easier, but it has a certain drawback - a relatively high price. A floorboard of the same quality will cost less, but installation will require more effort and more time.

The thickness of the plywood sheet should be at least 22 millimeters, otherwise your subfloor will sag under the weight of a person. In addition, the distribution of furniture throughout an apartment or house can cause a change in the topography of the subfloor. Experts recommend using thicker plywood if you plan to install heavy objects: wardrobe, refrigerator, sideboard with plenty of dishes, etc.

Sheets of plywood should be laid in a checkerboard pattern to prevent joints from being aligned. Screw the plywood to the joists using self-tapping screws, not forgetting to leave a distance of 2-3 centimeters from the wall for shrinkage and ventilation.

The subfloor is necessary as a reliable base for laying various coverings - parquet, laminate and other materials. A lot depends on the quality of the subfloor: squeaks when walking, service life, humidity and temperature in the house. Creating a subfloor at the stage of building a house differs from the same operation, which is performed during renovation by the method of attaching the joists. In this article we will talk about all the stages of creating a subfloor in a wooden house, so you can do this work yourself.

Mounting methods

All subfloors can be divided according to the method of fastening load-bearing structure:

• attached to walls;
• installed on a concrete base;
• ground mounted;
• combined.

Fastening the load-bearing structures of the subfloor to the walls is most in demand in houses installed on screw, column and strip foundation. More details about different types foundations, read the article -. This method of fastening allows you to create a rigid load-bearing frame gender, but requires high flow rate wood. The most popular mounting methods are using corners and in a cut-out groove. The first method is simpler, but less reliable, the second method is more reliable, but involves cutting through one of the crowns.

When installing a floor on a concrete base, various supports are used that allow you to raise the logs above the concrete. Brick pedestals are used as supports and metal fastenings. It is also possible to lay the logs directly on concrete, but in this case it will be necessary to carry out very high-quality waterproofing. In some wooden houses, the floor supports are installed on the ground. In this case, brick pedestals are built as supports. The combined method of attaching the load-bearing structure of the floor involves the use of the methods described above in any combination.

Subfloor design

The basis of the subfloor is the logs from which the supporting structure is assembled. In most cases, logs are laid in one row, but there are exceptions. If it is not possible to use a board of sufficient width and thickness, then the supporting structure is made double-row, placing the rows perpendicular to each other. I also use this design if the subfloor sheathing boards must be laid across the room, and for this it was necessary to lay the joists lengthwise, which increases the requirements for the width and thickness of the boards. Laying perpendicular supports under the top joists reduces the requirements for the width and thickness of the board. A rough flooring made of sawn, planed or profiled boards is laid on top of the supporting structure. This flooring not only creates a platform for laying the covering (finished floor), but is also an additional element of the supporting structure.

Tools for work

Whether you're installing flooring in a new home or renovating an old one, you'll need a variety of tools, such as:

• gasoline or electric saw;
• jigsaw;
• axe;
• chisels;
• screwdriver;
• drill;
• sander;
• hammer;
• level;
• a simple pencil;
• roulette.

Installation of the subfloor at the stage of wall construction

The easiest way is to make a subfloor during the construction of the house. To do this, it is necessary to cut through or non-through grooves in the timber or logs of the corresponding crowns, into which the logs will then be laid. Optimal distance between the logs - 60–80 cm. If the thickness of the board with which the logs will be sewn up exceeds 30 mm, then the distance between the logs can be increased to 90–100 cm. Lay the logs across the room. If the width of the room exceeds 4 meters, then it is advisable to install at least one support under each log or increase the thickness and width of the log by 1–2 cm. You can also use timber with a cross-section of 150x150 mm. This will reduce the likelihood of the floor sagging and squeaks.

Having chosen a board or timber to create a lag, measure its width and mark the corresponding crown for cutting grooves. If the wall is made of profiled or laminated timber, the width of which is equal to the width of the log, then cut through the entire beam, cutting pieces from it to fit the size of the log. If the wall is made of sawn or planed timber, then cut a groove ¾ of the width and thickness. After all, crowns made from such timber are not connected into a lock, so by cutting the timber, you will break the structure of the wall.

If you don't want lags to spoil appearance houses made of profiled or laminated timber, then cut the same grooves as on sawn timber.

Having prepared the grooves, cut the logs to length. If necessary, cut a lock on the joists to match the groove in the wall. Then cover the joists and wall cutouts with the protective substances you plan to use on your home. Read more about that. After the impregnation has dried, insert the joists into the wall and check their horizontalness using a level and a long, straight strip. If some joist protrudes above the others, trim it; if, on the contrary, it is lower than the others, put something under it. Immediately replace a crooked, twisted or cracked joist with a normal one.. If you cut the joists to create a castle, then to increase the strength of the house, install a support board under the joists that will take the weight of the floor. Attach this board to the wall using nails or self-tapping screws. Instead of boards, you can use steel and aluminum corners, which are sold at any hardware store. Attach these corners to the wall using thick long screws, and to the joists using bolts, washers and nuts.

Once all the joists are laid, leveled and secured, install the next crown, then cover them with the selected board. A tongue-and-groove floorboard is preferable because there is less heat loss through it. If you are insulating the floor, then first carry out all the insulation work, then sew it up with a board. Lay the board in such a way that the distance between the coating and the walls is 1–2 cm, this is necessary to compensate for the expansion of the coating due to moisture absorption. Also, do not push the covering boards all the way towards each other, leaving 1–2 mm between them, which will avoid swelling of the floor due to swelling of the boards. To attach the covering boards to the joists, use self-tapping screws 70–120 mm long. If you cannot screw in a self-tapping screw of this length, then first drill a guide hole with a diameter of 1.5–2 mm.

Replacing an old floor in a wooden house

If the old wooden floor has rotted or you decide to replace it for some reason, remove the finished floor and subfloor covering, this will allow you to assess the condition of the joists and walls. If the old joists are damaged, remove them completely by cutting them flush with the wall. Inspect the crown where the joists were cut into; it may need to be repaired or replaced. If the crown is in order, sand it with a sander and cover it with protective compounds. Also treat joists and flooring boards with protective compounds.

To learn how to do this, read the material about. Mark the installation locations for the joists on the wall and draw a line along their bottom. At the bottom, close to this line, attach a support board on which you will lay the logs. Place the outermost logs at a distance of 10–15 cm from the walls, the remaining logs at a distance of 60–100 cm from each other (depending on the thickness of the covering boards). After installing the joist, fix it with a corner, as described in the previous section, or support it on both sides with bosses made from scraps of the support board or joist. This fixation will securely secure the joists and prevent squeaks. After this, cover the subfloor with boards as described above.

Subfloor with supports on the ground or concrete

The difference between this floor and those described above is that the main load falls not on the walls, but on the ground or concrete. This is true for old houses and for buildings standing on slab foundation. If you are replacing the floor, remove the old boards and clean and repair the walls as described in the previous section. Then determine where the joists will be installed and where the support pedestals will stand. If you place the cabinets on the ground, then dig a foundation for them, a square or rectangular hole with a cross-section of 1x1 meter and a depth of 20 centimeters. Compact the bottom of the hole and pour a 5 cm thick layer of sand on it. Pour a 5 cm thick layer of crushed stone on top, then pour a reinforced concrete pad 10 cm thick. After 5–7 days, lay a brick support on this pad with cement mortar. The height of the support should be such that there is a distance of 1–2 cm between it and the bottom side of the joist. Upper part the supporting pedestal is covered with bitumen and roofing felt to ensure waterproofing of the lag. Then the logs are installed as described in the previous section, after which wedges or spacers of the required thickness are inserted between the supports and the logs, which will raise the log by fractions of a millimeter. Covering the logs with floorboards is carried out in the same way as described above.

Floor insulation in a wooden house

Warming – required element creating a subfloor in any wooden house. Insulation reduces heat loss at home and increases the comfort of living in it. Without insulation, a wooden floor loses half of its positive qualities. Details different methods insulation of the subfloor in a wooden house is described in the article -. Do not neglect this procedure, thanks to which you will be able to walk around the house in winter even barefoot.

The concept of “subfloor” hides not just poorly processed boards, but a real “pie” of various materials, which together form solid foundation for finished floor. By the way, the subfloor does not have to be wooden; it can also be a concrete screed on the ground. The technology for arranging a subfloor includes a set of measures that provide hydro, heat and sound insulation of the base. In this article we will look at how you can make a durable and reliable subfloor on which you can lay any finishing coating.

How to make a wooden subfloor on the ground

IN country house arranging the floor is a responsible and time-consuming task. Wooden flooring on the ground can be done without restrictions. Even if you live in a house temporarily, when the heating is not working, the wooden floor lasts for a long time without changes, since the underground is well ventilated through vents in the foundation.

For wooden elements For floor construction, it is necessary to select high-quality dried wood with a moisture content of no more than 12%. This is important, since wet wood can “lead” during operation. For the subfloor in the house choose conifers wood - spruce, pine, fir, larch. Wood saturated with resins is less susceptible to rotting and mold development.

Also, wood for joists and subfloors must be treated with an antiseptic and fire retardant.

The underground wooden floor on joists should be well ventilated. To do this, vents are made in the foundation, which are covered with a mesh with a mesh size of no more than 8 mm, so that mice do not get inside.

Wooden floor base

The design of a wooden floor on the ground assumes that the floorboards will be laid on logs - longitudinal beams. Depending on the characteristics of the house, logs can be laid on support beams, a crown molding or on support posts.

If the room is large enough, fixing the logs only at the ends to the beams will not be enough; the structure will turn out to be fragile. Therefore, in the spaces between the walls, support columns are installed on which the logs will be laid. The pitch between the columns depends on the cross-section of the lag. For example, if a 150x150 mm beam is used as a log, then the distance between the support posts should be no more than 80 cm.

How to make support pillars for joists:

• First we make markings where the logs will be located. We make marks on the support beams or foundation of the house. Then we stretch the cords across the entire underground. We stretch the cords across the future logs at a distance of 80 cm or any other distance that is equal to the step between the posts. Support posts will be located at the intersections of cords or ropes.

• In the places where we will make support pillars, we dig a hole 40 - 60 cm deep, with sides 40 cm.
• At the bottom of the pit we compact the soil, pour a 10 cm layer of sand, and then 10 cm of crushed stone. We carefully compact each layer one by one. This will be our backfill for the foundation of the column.
• We install wooden formwork in the hole to pour the foundation under the concrete column. If the support columns are made of brick, then the height of the foundation should be such that it rises 5 - 10 cm above the ground level. If the entire support column is cast from concrete, then the height of the formwork should be such that the logs laid on the column are positioned horizontally.
• Inside the formwork we insert a reinforcing frame connected from steel rods with a cross-section of 6 - 8 mm.
• We pour concrete.

Important! If the entire column is poured from concrete, then it is necessary to ensure that the surface of the column is exactly horizontal and that all columns are at the same level.

• After the concrete has completely dried, cover the surface of the column with roofing material or glass insulation in 2 - 3 layers. Definitely no sprinkles. Coat the surface and joints with mastic.

If you want to make support columns from brick, then the masonry must be fastened with cement mortar. For a column less than 25 cm high, the masonry should be 1.5 bricks; for a higher column, a masonry of 2 bricks will be required.

After the concrete has dried, the formwork can be removed. For greater reliability, it is better to remove fertile soil from the underground. It must be removed to a depth of 20 cm. Instead of soil, it is advisable to add 10 cm of gravel and 10 cm of sand and compact it thoroughly with a vibrating plate.

Before arranging the base, it is necessary to treat the beams, joists and subfloor boards with an antiseptic. The logs can be laid directly on the embedded crown or foundation and on the support columns, or you can first install the support beams on the columns, and then the logs across the top. Any option is correct. Only laying the logs across the beams provides a more stable and durable structure if the distance between the logs is very small, 40 - 60 cm.

The cross-section of the lag must be selected taking into account the thickness thermal insulation material, which will fit between them. For example, if the thickness of the insulation is 150 mm, then it is necessary to take a beam with a height of 180 mm. A ventilation gap of 30 mm must always be left.

The pitch between the lags is selected taking into account the thickness of the boards of the future floor. More precise instructions can be found in the table below.

Table 1. Lag step.

Let's consider laying lags on support posts:

• We lay the logs on the embedded crown (support beams, foundation) and support posts. We control their even position, horizontal. A noise-absorbing material can be placed on the surface of the support posts under the logs. But this is not necessary, since roofing felt or other waterproofing material, which covers the surface of the post, springs well and conceals sounds.
• If, however, sagging of the logs is noticed somewhere, it is necessary to place wooden blocks on the support posts under the logs and secure them firmly. If a beam sticks out somewhere, it can be cut off with a plane.

Important! The maximum permissible deviation in the evenness of the joists is 1 mm per 1 m.

• We fix the logs to support pillars using mounting brackets. On the wood side we secure it with self-tapping screws 50 mm long, and on the concrete column side we tighten the anchor.
• The first to lay the so-called “beacon logs”, which are located at a distance of 2 m from each other. We will follow them further.
• By analogy, we lay all the logs and check their even position.

After all the logs are secured, you can begin arranging heat and waterproofing.

Thermal insulation and waterproofing of wooden floors

Waterproofing and thermal insulation materials are laid between the joists. To secure them, it is necessary to arrange the base. There are several ways to do this.

Method 1. Sheets of moisture-resistant plywood can be nailed to the bottom of the joist. This design will be as reliable as possible. To do this, you will have to work underground, which is not always possible.

Method 2. At the bottom of the lag you can nail 20 mm thick cranial blocks, and roll the boards on top. This work is more painstaking, since you will have to cut a lot of boards with a cross-section of 15 mm and a length equal to the pitch between the logs.

You can choose the method that you like best. The main thing is to get a fairly strong foundation.

• We lay a layer of waterproofing with an overlap of 15 - 20 cm, and seal the joints with construction tape.

Important! Be sure to use a superdiffusion, vapor-permeable membrane. We need the waterproofing material to release moisture from the room, but not let it in from the underground. Therefore, ordinary plastic film cannot be used.

• We lay thermal insulation material on top of the film between the joists. We cut the rolled material with a width equal to the pitch between the lags plus 1 - 2 cm, so that the material fits into the gap between the lags at random.

Important! As insulation for a wooden floor, you can use mineral wool in rolls, slabs, basalt wool, you can blow in ecowool, sawdust. Polystyrene foam and extruded polystyrene foam cannot be used. These materials are completely vapor-tight; a wooden floor simply cannot breathe.

A ventilation gap of 2 - 3 cm must be left on top of the insulation.

Laying the subfloor

Now you can lay the subfloor in the house. There are several options for arranging rough flooring. The material can be used floorboard 15 - 25 mm thick with minimal processing. You can also use tongue and groove flooring if finances allow. For subfloors, the price depends on the cost of the materials used. If you use thick massive board, then there is no point in laying a subfloor from a floorboard. Or you can lay down sheets of plywood and lay a finished floor covering on top.

Subfloor from floorboards:

• We start laying from the wall. We cut off the tenon and apply the board to the wall, leaving a gap of 2 cm.

Important! A distance from the walls is required, since wood is a plastic material; when it absorbs moisture, it expands, and when it dries, it shrinks. The gap will provide unhindered opportunity for the wood to expand and shrink.

• We fix the board to the joists. From the wall side we screw the screws directly into the board, then this place will be hidden by the baseboard.
• From the tenon side, screw the screws into the tenon at an angle of 45 degrees.
• We move the next board close to the first. We insert it into the groove of the first board.
• We screw a self-tapping screw into the groove of the second board, securing it to the joist.
• We lay all subsequent boards by analogy.

Important! If the boards are the same length as the room, then they can be laid exactly parallel to each other. If the boards are shorter than the room, then they must be laid offset - staggered.

The last board is secured so that the screw heads can be hidden under the baseboard. At this point the subfloor is ready. The main thing is to fit the boards tightly to each other. You can lay flooring on top.

How to make a wood subfloor on a concrete base

In apartments with concrete floors You can also make a wooden floor. The logs are laid on a concrete base, but for this it must be level. A height difference of several centimeters is unacceptable. Therefore, the option of placing wooden blocks under the sagging logs is not suitable. Over time, the pads will dry out and become deformed, which can easily cause them to fly out and the floor will begin to creak.

Preparation of the base: hydro- and sound insulation

Before laying the joists on the concrete floor, it is necessary to level the base. To do this, pour a cement-sand screed. Further work can be continued only after the concrete has completely dried, i.e. a month later.

We lay a waterproofing film on the surface of the concrete screed with an overlap of 15 - 20 cm, and seal the joints with tape.

We place soundproofing pads under the joists. To do this, you can use cork materials or foamed polyethylene with a thickness of 1 - 4 mm. Lining under the joists is needed to dampen impact noise.

Laying joists on concrete

It is advisable to use a beam equal to the length of the room. If this is not possible, then you can take a shorter beam and connect it to the end. The connection points should be spaced apart.

• We lay the logs on the prepared base.
• We check the horizontal position of the logs.
• We fix the logs to the floor using corners. Do not forget that the corners themselves are attached to concrete floor anchors.
• After laying and securing all the joists, we lay the insulation between the joists in the same way as in the case of a floor on the ground.

Do not forget to leave a ventilation gap of 2 - 3 cm.

Installation of subfloor

We lay a subfloor on top of the joists. As mentioned above, it could be plywood, or it could be a floorboard.

Consider the option of arranging a subfloor made of plywood:

• We take a sheet of moisture-resistant plywood with a thickness of 22 mm.
• We lay a sheet of plywood on the joists and fasten them to them with self-tapping screws in 15 cm increments.
• We arrange the plywood sheets in a checkerboard pattern. To do this, some of them will have to be cut.
• The joints of the plywood sheets must not be on the same line.

Do not forget that there should be a gap of 2 - 3 cm between the wall and the subfloor. The following floor coverings can be laid on top of the plywood base: laminate, linoleum, ceramic tiles, vinyl tiles, parquet, parquet board, massive board.

Installation of rough concrete floors on the ground

It is not always possible to pour a concrete floor in a private house over the ground. There are certain restrictions. Firstly, the groundwater in the area must be quite low - at a level of 4 - 5 m. Secondly, the soil must be stable and not mobile, otherwise the concrete floor may collapse. Thirdly, people must live in the house permanently, or it would be more correct to say that it must be heated during the cold season. If all conditions are met, you can safely pour the concrete slab on the ground.

Excavation and foundation preparation

First of all, it is necessary to outline the “zero” mark - the level of the future floor. You need to orient yourself along the bottom of the doorway. All walls must be marked so that in the future you can see until when to pour concrete.

• The floor on the ground is a multi-layer structure 30 - 35 cm thick. To equip it, we remove upper layer soil until the height from the zero mark to the bottom of the pit is 30 - 35 cm.

Important! If the ground level is below 30 - 35 cm from the floor level, then it is necessary to level the ground surface, compact it, add sand until required level and also tamp down thoroughly.

• We compact the base of the pit.
• Pour a 10 cm layer of crushed stone and compact it thoroughly. If the thickness of the backfill is difficult to control, then we hammer several pegs into the ground at the required mark. After leveling and compacting, the pegs can be removed.

• Pour the 10th layer of sand, water it and tamp it too.
• Pour a small layer of crushed stone on top with a fraction of 40 - 50 mm.
• Sprinkle with sand, forming a thin layer, and compact thoroughly.

Important! If suddenly sharp edges of crushed stone fractions are observed on the surface of the base, it is necessary to unroll the pebble and place it so that there are no sharp corners anywhere.

At all stages of backfilling, it is necessary to ensure horizontality.

Waterproofing, thermal insulation, reinforcement

• We lay a waterproofing material on the surface of the base - polyethylene film with a density of 200 microns, roofing felt or glass insulation. The main thing is that the material is not damaged by the edges of the crushed stone.
• We apply waterproofing material to the walls to a level 2 cm above the floor level. We lay it with an overlap of 10 - 15 cm and glue it with tape.

• At this stage, you can lay durable thermal insulation material. For example, extruded polystyrene foam or basalt wool in slabs, perlite or expanded clay. You can also place the thermal insulation layer higher, on top of the concrete base.

• Concrete floors must be reinforced. For this we use metal mesh with cells 10 cm.
• We install the reinforcing mesh on stands 2 - 3 cm high so that the mesh is completely inside the concrete.

Installation of formwork and guides

To maintain a horizontal floor level, it is necessary to lay so-called “beacons” or guides. For these purposes, you can use round and square steel pipes, wooden blocks. We place them in increments of no more than 1 m. We secure them with thick cement mortar. You can also control their height by pouring more solution under the guides.

We install formwork between the guides to fill the floor. This is not necessary, but it makes the task of pouring a concrete floor by hand much easier.

We treat the guides and formwork with oil or polish so that after pouring they can be easily removed.

Rough floor screed - pouring concrete

It is necessary to pour a concrete floor in a house in one or two passes. If you take long breaks, the foundation will turn out to be fragile.

• We begin pouring concrete from the corner opposite the front door.
• Fill several cards at once, then level them with a shovel.
• We compact the concrete using a deep vibrator.
• Level the surface using the rule. We set the rule on the guides and pull it towards us. Excess solution is distributed among cards that do not have enough solution.
• We take out the cards and fill the voids with concrete.
• When the entire floor is poured with concrete using this technology, it must be covered with plastic film and allowed to dry for a month.

For better drying of the concrete subfloor, its surface must be moistened with water.

After the concrete has completely dried, you can finish screeding the floor and laying the floor covering.

Making a subfloor with your own hands is a very important task, because a solid foundation is much more important than a finishing coating. For example, in an old house, you should not lay new flooring on top of the old subfloor unless it has been completely renovated.

Even without reading the instructions for laying a particular coating, you can immediately say that the base on which it will be laid must have such qualities as evenness, strength, dryness and cleanliness. But how can you get this if in front of your eyes is a surface that is clearly far from ideal? It is somewhat difficult to answer the question unambiguously, since under different coatings the subfloor can meet different requirements.

Floors are a kind of structure that consists of two types of bases - “finish” and “rough” and lies on a load-bearing base. For example, between floors this function is performed by the ceiling, or more precisely, its load-bearing elements. Depending on what material is used for the finished floor, it can be plank, parquet, tile, concrete, etc. As for the rough material, which lies under the finished floor, it is a multi-layer “pie”, the structure of which is determined by:

• base design;
• finishing type;
• General requirements.

The construction of subfloors, in any case, despite the differences, combines the same components:

• underlying - taking the load from the coating, evenly distributing it over the base and transferring it to the walls; this role can be performed by a floor slab and soil that has undergone preparation that meets the requirements;
• leveling – dense enough to level the surface of the previous layer; at the same stage, perform the planned slope of the surface, using a screed or resorting to other methods;
• intermediate - a layer-ligament between the coating and the underlying layers of the floor;
• insulating – provide noise, heat and moisture insulation; where exactly they will be located depends on the functional load of the structure and the method of installation.

The rough floor is laid from low-quality boards, that is, slabs, waste boards, picket fences - everything on which it is possible to lay heat-, steam- and waterproofing materials. The point here is sensitivity to humidity and temperature fluctuations, therefore, in order to minimize, as far as possible, the deformation of the subsequent finishing material, materials that are capable of deformation are chosen for roughing. Depending on where it is being built, perform:

• along the beams,
• according to the logs,
• on the ground.

The first ones are installed above uninsulated undergrounds, and the finished floors of the first floors should be 80–100 cm above the ground. In this case, a vapor barrier layer is laid between the flooring and the plank floor.

Installation on joists

You can do it yourself. For leveling with this method, a special frame made of wooden blocks is used - a lag. Such structures are laid in buildings where the height of the underground is no more than 25 cm. They are supported on antiseptic wooden pads of the following dimensions: length - 20-25 cm, width - 10 mm, thickness - from 25 mm. When laying on joists, the following recommendations must be followed:

Many people are concerned about the question: is it possible to lay logs without significant damage to quality at a lower cost? Yes, it is possible - the solution is to lay the logs in a sparse manner. In addition, with a low landing, the floor may not be insulated. One of the important points in this technology is the choice of flooring. This should be a thin, untreated board, which is then laid in a diagonal direction. A board thinner than the standard one will also be suitable for finishing coating - anyway, the total thickness of the base will be within the normal range. Moreover, the intersection of fibers gives the effect of plywood, which eliminates deflection under the influence of loads.

The construction of the subfloor can also be carried out on floor slabs, since the flooring is in this case does not require any supports or joists.

On the ground: we provide a basement, insulation

When installing floors on the first floors, it is often rough. The schematically generalized design of his “pie” looks like this, starting from bottom to top:

• well-compacted bedding made of river sand– 50–70 mm;
• or crushed stone – 100–120 mm;
• rough concrete screed – 50–70 mm;
• thermal insulation - depending on the region of location;
• finishing screed – minimum thickness – 50 mm, reinforced with mesh, cell – 10x10 cm.

If there is no basement and there are no special loads expected on the ground floor; rough screed, as such, need not be done. In these cases, the filled expanded clay is poured with a liquid solution of cement and sand, taken in a ratio of 1:2, allowed to harden and the subsequent layers continue to be laid, starting with waterproofing.

If you plan to lay a heated floor, then you need to provide a gap of 10–20 mm between the subfloor and the foundation. It is usually filled with foamed polyethylene or polyurethane. This is done in order to prevent concrete from cracking during thermal expansion.

An important point is also the level of the finishing screed.

• If the base is not insulated, the screed is placed above the level of the top of the base. Otherwise, a “bridge” of cold will form in this place and the wall will freeze.
• With an insulated base there are no restrictions.

Insulation of the subfloor

With any technology, roughing and finishing should be located at different levels:

• draft,
• free space,
• finishing

Thermal protection of the floor is provided by filling this void with insulation. Before installation, the subfloor is additionally treated with an antiseptic, even using used motor oils, and a vapor barrier is installed.

It is not recommended to use this option in a residential building due to the persistent specific “aroma”.

The best insulation option is considered mineral wool, although it can be replaced

• any other synthetic insulation that is not subject to rotting;
• loose expanded clay or;
• hard foam.

Ventilation holes should be provided in the corners.

Waterproofing is an important stage of a warm home

The installation of waterproofing in rooms that are distinguished requires special attention high humidity, say, bathrooms. The choice of technologies is quite wide. For example, coating waterproofing using special penetrating compounds, or waterproofing with synthetic components such as polyurethane, epoxy resin and others. Coating polymer-cement waterproofing with either quick-setting elements or synthetic additives is considered the most effective. The latter are especially relevant for houses with an unstable foundation.