Currently, the main criteria for flooring subfloors are strength and reliability, since the quality of floor installation depends on them. finishing material. To ensure that the floor is level, experts advise giving preference to adjustable structures that are built along joists.
An adjustable floor on joists is a floor device located on special boards, under which there is an underground space. Thanks to this, the floor surface does not require additional leveling using a concrete screed.
A threaded anchor for an adjustable floor is attached to a base, which can be wood, concrete or dirt. The height of the floor is adjusted due to the ability of the clamp to rotate around its axis.
Anchors are attached to the base depending on the type of subfloor:
The anchor structure performs the following functions:
Adjustable floors have big amount advantages, among which are:
To begin with, you need to secure the logs to the base in increments of 30-50 centimeters using screw-in bolts. Then the logs are leveled, for which the stand bolts are rotated along the axis using a special key. Finally, a double layer of plywood is laid on the joists, with the thickness of each sheet being at least 12 millimeters. In the event that in the future it will be laid ceramic tile, to lay the top layer you need to use moisture-resistant plywood with a thickness of about 10-12 millimeters.
When installing adjustable plywood, 16 through holes are made in the plywood using a spade bit. Then they insert plastic bushings, into which the post bolts are screwed. After this, you can begin to level the sheets by rotating the bolt stands secured to the base with dowels.
Attention ! To install the floor, it is necessary to use logs made of durable wood with a humidity of 12 to 14%. They should not have cracks or knots, traces of mold or rodent damage. The length of the logs is usually 2 meters, and the cross-section is 4.5 by 4.5 centimeters. Before starting work, the material should be treated with special protective compounds. There must be enough air in the underground for ventilation.
The main advantage of such a floor is that it becomes possible to create a perfectly smooth and even subfloor on an unprepared base. Thanks to this, almost any floor covering can be used in the future.
By erecting a structure of this type, it is possible to mask any systems (ventilation, heating, electrical, etc.). If a “warm floor” system is installed in the room, then its installation, carried out according to this design, will significantly reduce heat loss through the floor and, thereby, significantly save electricity.
Despite the fact that such an adjustable design is characterized by a fairly low weight, it is capable of withstanding heavy loads, which can reach up to 2500 kilograms per 1 square meter. Thanks to this, adjustable floors have found their use not only in furnishing living rooms, but also warehouses, gyms and other premises.
Houses with such a floor structure can be built even on soils in which heavy loads on the foundation are strictly prohibited. If the floor cannot be raised too high, then you can use a special design on adjustable plywood, in which the rise will reach only three centimeters.
The technology for installing it is almost no different from installing logs. The main difference is that instead of joists, naturally, sheets of plywood are used.
Plywood is a material used not only in households, but also in aircraft construction, shipbuilding, furniture production and many other industries. With the help of plywood, you can easily replace a damaged section of the floor, because it goes well with floor coverings from linoleum, laminate, carpet and parquet. But to avoid any misunderstandings, you need to know how to lay plywood correctly.
Advantages of plywood over other materials:
Adjustable plywood is excellent in cases where the floor has distortions exceeding 15 centimeters, or communications pass through it.
Attention ! When adjusting the floor along the joists, the height of the room usually becomes lower by about 7-8 centimeters, so it is recommended to use it in rooms with high ceilings. In turn, when laying floors on adjustable plywood, the floor rises no more than 3 centimeters, so the second method is considered more effective.
When using this method, the logs are replaced with bushings, inside of which there is a thread (for this, special holes are drilled in the plywood). 6 plastic bolts are screwed into the bushings, which must then be attached to the base using a dowel. A wrench should be used to level the adjustable plywood.
First you need to carefully level the first layer of plywood, then install the next layer and screw it with self-tapping screws. Before laying the second layer, you need to carefully overlap the joints of the previous one, which will avoid the formation of seams. Thanks to these actions, the floor surface will become even and smooth.
The technology of adjustable floors appeared on the market relatively recently, but has already gained popularity among builders, and good feedback from the users. Why? The answer is simple - it has a lot of advantages. Among them are the following:
In fairness, we also note flaws:
However, as you can see, there are many more advantages to an adjustable floor and they are quite easy to obtain. The technology is so accessible that it is possible to build adjustable floor Can with your own hands and without professional training. And this one instructions, we hope this will help you.
Before you start work, you need to decide on the design of the floor, as well as prepare tools and materials. But first things first:
Design
In practice, both are used. But the first ones gained the most popularity. However, despite the different permissible lifting heights, the technology for their construction does not differ significantly.
Tool
The minimum tools you will need to work on the construction of an adjustable floor consists of:
Material
The amount of material depends on the size of the floor. But, for understanding, we will give a calculation of the amount of materials for 5 square meters.
For slab adjustable floors you will need:
To install floors on joists you will need: timber, section 45x45 - 14 m.p.;
Features of choosing timber
Dried timber made from pine wood can be used as lag.
Features of material selection
An important point is to choose the right material. Professionals recommend giving preference to plywood. This option can provide simultaneous floor insulation with plywood. To form one layer, the sheet thickness must be at least 18 mm. If there are two layers, it is permissible to use sheets with a thickness of at least 12 mm.
It is permissible to use 3/4 grade plywood. But moisture resistance requirements must be met. Permissible humidity is no more than 12%. What is achieved by using FSF or FK plywood.
Installation technology
Let's consider two options
Option 1 - Floors adjustable by slabs
Such a floor is installed if the surface is characterized by slight deviations from the level. And the ceiling of the room is low. Those. there is a need to save every centimeter of height.
The installation process in this case is simple and consists of the following steps:
1. Cut the plywood sheets into the required pieces. Place them on the floor and label them. In order to know exactly where each sheet will be located in the future.
2. Holes are drilled in the plywood sheets required diameter. Bushings are inserted into them.
3. Sheets of the first level are laid on the floor surface
4. The sheets are fastened to the floor using dowels.
5. Using a key, the height of the floor is adjusted by tightening the threaded bushings.
6. It is necessary to use a building level.
7. All protruding parts (threaded bushings) must be cut off.
8. If a second layer of plywood is provided, it is laid on the first one and secured with self-tapping screws.
When laying the second layer, it is important to follow the sequence of laying the sheets. And ensure that there is no construction waste between them. To do this, the surface must be vacuumed.
The seams of the previous layer should not coincide with the seams of the next one. Figuratively speaking, they should be arranged like bricks, overlapping each other.
9. Floor covering is laid.
Option 2 - Floors adjustable by joists
1. Drill holes in the joist beam. The distance between them should be within 300-450 mm. The higher the load planned on the floor, the more often the joists should be drilled.
2. The arrangement of the logs begins with the ends that are attached to the floor. Then the middle of the beam is attached. It is important not to fully tighten the bolts right away in order to be able to adjust them.
Please note that the control device can be made independently. For this you will need:
3. Logs are set according to level.
4. The height of the floor is adjusted by tightening the bolts.
5. Protruding bolt heads are removed using a chisel.
6. Sheets of plywood are attached to the joists. The mounting method is similar to that described in the first option for arranging an adjustable floor.
Conclusion
This approach to flooring is becoming increasingly popular. This is due to the ease of installation, the relative cheapness of materials, and the ability to do everything quickly and without the involvement of expensive professionals.
600 rub.
RUB 3,500
170 rub.
RUB 1,350
550 rub.
1,000 rub.
450 rub.
750 rub.
RUB 2,300 RUB 3,000
225 RUR
RUB 1,900
A new technology for many of our compatriots, it makes it possible to significantly reduce the time for arranging floor coverings. Like any technology, in addition to its advantages, it also has rather “problematic” characteristics. But this is the professionalism of builders: to be able to choose from among the numerous options for flooring the one that will be optimal in this particular case.
Finish floor coverings are installed on wooden joists (in the case of using floorboards) or on a solid base made of sheets of plywood or OSB (in the case of using laminate or soft coverings).
Very important point During the construction of any floors, the load-bearing surface must be located in a strictly horizontal position.
It is very difficult to achieve such a result with the help of fixed logs; you often have to use various wedges or pads to level the spatial position. These wedges may fall out due to improper fixation or for other reasons, and the floors begin to sag and creak. It is impossible to eliminate such problems without dismantling some of the coatings, and dismantling is associated with large losses of time and money.
Adjustable floors with your own hands - a diagram of one of the possible options
Adjustable floors allow you to perfectly level surfaces on any uneven surfaces. In addition, the leveling mechanism makes it possible to adjust the gap between the floor and the load-bearing base, and this makes it possible to place various utility networks in these places.
Adjustable floors consist of plastic stud bolts or metal studs, floor joists, or plywood sheets. Many modifications of regulatory systems are made, but there are no fundamental differences between them. By rotation threaded connection there is a smooth lowering/raising of structural elements, in this way you can accurately set the base of the floors in the required position.
There are several types of adjustable floors, you should familiarize yourself with them in more detail.
Table. Types and brief characteristics adjustable floors
| Types of adjustable floors | Characteristics | Illustration |
|---|---|---|
| With plastic adjustment mechanism | They can be sold assembled with lags or as separate kits. Factory floors are much faster to install; they have pre-cut threads in the joists, so there is no need to mark and drill holes. The dimensions of the log are 30×50 mm, the distance between the bolts is 40 centimeters. It is recommended to install logs in increments of 30÷40 centimeters; specific values must be selected taking into account the expected maximum load on the floor. |
|
| WITH metal mechanism regulation | Instead of plastic connections metal studs with nuts and washers are used. They can withstand increased loads, but working with them is somewhat more difficult. |
|
| On metal corners | Advantage - the stability of the log increases, it is possible to create complex designs floors, taking into account the specific layout of the rooms. Disadvantage: installation time increases significantly. |
|
Both joists and slabs can be adjusted. The second option is used only for laying soft flooring or laminate, the first option can be used for all types finishing coating floor.
If you wish, you can make adjustable floors yourself; this option has its own undeniable advantages. The main ones are significantly lower cost and the ability to select log parameters depending on the specific features of operation. If desired, the system of adjustable floors allows for floor insulation, which is very important in conditions of high energy prices.
Initial data. Load-bearing base - concrete or cement-sand screed, a set of factory-made adjustable logs is used. Let's say right away that this is the most expensive option for adjustable floors.
Step 1. Take measurements of the room to determine the number of joists. The floors in the bathhouse do not have a large load; the distance between the logs can be increased to 45 centimeters.
Step 2. Beat off the distances between the lags. To do this, use a rope with blue, with its help the work will be done quickly and efficiently.
Step 3. Cut the joists to the required length. The length of manufactured factory logs in most cases is four meters. Carefully consider how to mark the joists to minimize the amount of waste. The distance from the cutting line to the nearest adjusting bolt must be at least ten centimeters. If the end is closer, then there is a risk of cracks forming under loads.
Step 4. Place the joists near the marked lines. For installation you will need a small drill with a hammer drill, a special wrench for screwing in bolts, a hammer for fixing dowels, a screwdriver, a chisel and a hammer.
Step 5. Place the first joist in a vertical position and screw plastic bolts into the threaded hole. Place the bottom ends of the bolts in line and drill a hole in the concrete base for the dowel. The depth of the holes for the dowel should be 2–3 centimeters greater than its length. This is due to the fact that a certain amount of concrete always remains in the hole; if you do not make a reserve in length, it will prevent you from driving the dowel completely.
Step 6. Attach the dowels, but do not drive them all the way in. The dowel should not interfere with the rotation of the plastic bolts. Use a long level to set correct position lag If the joist is installed, firmly fix the dowel. Continue to install the logs in the marked places one by one, constantly monitoring their position with a level.
Manufacturers offer this installation algorithm, as do many builders who receive wages not based on output, but hourly. Those who work from the workings do things differently. How? They take a hydraulic level and beat off on two opposite walls zero level lag Then nails or dowels are driven in these places (depending on the material of the walls) and the ropes are pulled. The ropes are tensioned so that they are located at the ends of the joists. If the length of the room is not greater than the length of the logs, then you will need two ropes. If the logs had to be connected, then three. The rope is tensioned only after the logs have already been placed at their fixation points.
Then everything is simple and fast. Each lag is installed along the rope; it should not touch it; you need to check that the gap between the rope and the lag is minimal. That's all, in this way you will be able to not only significantly increase the speed of installing an adjustable floor, but also significantly improve its quality.
There is a direct relationship between accuracy and the number of measured planes. What is meant? There is a high probability that the position of the first log has deviated from the desired level by one millimeter. It's not much, it's okay. But the fact is that the next checks will be done taking into account this deviation, again the probability of an error of a millimeter appears, and so on in increasing order. It is for this purpose that a template is made, if you need to cut a large number of identical parts, rather than taking measurements from each finished part one by one. IN in this case the rope acts as a template.
Step 7. Using a wide chisel, cut off the protruding part of the plastic bolt.
Floor with plastic bolts - check
plastic bolts
The main advantage of such floors is that the stability of the fastening is significantly increased by increasing the area of the lower stop. Disadvantage: the deadlines increase, the inability to do the work yourself.
The logs are fixed to the U-shaped plates using self-tapping screws; the height of the logs is adjusted using a series of vertically located holes on both sides of the plate.
Step 1. Using a blue rope, mark the locations of the floor joists. Calculate the required amount of material and additional structures.
Step 2. Determine the floor level, make marks on the walls. Place metal plates and joists along the lines. The width of the plates must correspond to the lag tire. The distance between the plates depends on the parameters of the log; forty centimeters is enough for a bath.
Step 3. Use dowels to secure the plates to the concrete base. Immediately hammer in the dowels until they stop, then it is very difficult to tighten them - the log lies on top and prevents access to it. If the metal plates move a little during fixation, it’s okay. When installing the joists, slightly bend their side parts in the desired direction.
Fixing the bracket
Step 4. Take the first lag and place its ends in the desired position. In this position, attach the log to the side surfaces of the U-shaped plates; use wood screws for fixation. Now you can fix the plates located in the middle of the log. But to do this, constantly check the horizontal position; the joist bends a little under its own weight. If you want to do the work faster and better, then use ropes to set the horizontal level. How this is done is described above. Make sure that the self-tapping screws do not split the joists, choose them according to size, and screw them in at a slight downward slope.
Step 5. After installing all the joists, you need to cut off the protruding parts of the plates with a grinder. This is quite inconvenient to do. But, despite the “difficult” cutting conditions, try to minimally damage the wooden joists with the disc.
Adjustable floors of this type can be made independently; we will talk about this option. Select the dimensions of the joists taking into account the characteristics of the floor and maximum loads. Metal studs with zinc coating, recommended diameter 6÷8 mm. To assemble the structure you will need studs, nuts and washers.
Step 1. Beat off parallel lines on the supporting base at a distance of 30÷50 cm. longer distance, the more powerful the logs you need to choose.
Step 2. Make calculations based on the number of joists, studs, washers and nuts. The recommended distance between the studs is 30÷40 centimeters. Prepare all materials, additional elements and tools for the work.
Step 3. Mark the holes in the joists for the studs; they should all lie on the line of symmetry. In the designated places, first drill a through hole Ø6 mm for the stud (if the diameter of the stud is different, then the hole must be drilled accordingly). WITH front side logs, use a feather drill to drill a hole for the diameter of the washer. The depth of the hole should be several millimeters greater than the sum of the height of the nut and the thickness of the washer.
Step 4. Place each joist in turn on the broken parallel lines on the concrete screed. Very carefully, one by one, mark the future installation locations of the anchor threaded elements for each joist. Make sure that the joist does not move. For marks, use a drill or an ordinary pencil. For a drill, you need to take a drill with a pobedit tip. The places are marked - take away the lag and drill holes in the concrete. The dimensions of the hole must correspond to the dimensions of the anchors.
There is a second way to mark holes for anchors; it takes more time, but completely eliminates the possibility of errors. It's done like this. First, you need to mark only the two outer holes for the anchors, screw the studs into them on two nuts, and fix the joist in the desired position. Now during further marking the lag will not move anywhere. In this position, you can immediately drill holes for the anchors to the full depth. The work is completed - the joist is removed, all the studs are screwed into place. This procedure will have to be performed with each lag; labor productivity is reduced by half. But you must make your own final decision on the marking method, taking into account the condition of the concrete subfloor and your experience in performing this type of work.
Step 5. Screw a nut onto each stud and place a washer. It is advisable to immediately determine approximately the location of their height, this will speed up the work. Screw the studs into the anchors firmly. To do this, you can use a special plumbing tool or other simple methods. You can buy studs that have holes at the end for an insert barb or a hexagon for an open-end wrench, but they cost much more than ordinary ones.
Step 6. Place the logs on the studs one by one, using a wrench of the appropriate size by turning the bottom nut left/right to align the position of the logs. We have already told you how this is done. Keep in mind that the thread pitch of metal nuts is much smaller than plastic ones. In some cases, you will have to twist for quite a long time, which is tiring. Moreover, the position will be uncomfortable: you will have to sit on your knees and bring the key from below the joists.
Step 7 The logs are exposed - you can start fixing them. Use a washer and nut and insert them into the top hole.
Important! Tighten the top nut with great force; even a slight loosening can cause very unpleasant squeaks when walking on the floor.
Step 8 Cut off the protruding ends of the studs with a grinder. Be careful with the joists, do not damage the integrity of the lumber with the saw blade.
This subfloor is only suitable for laminate or soft flooring. For installation, you need to buy a set of factory-made elements; the work is more difficult to complete.
Step 1. Mark the installation locations for the bushings on a sheet of plywood and drill holes of the specified diameter. The bushings should be evenly distributed over the entire area of the sheet, the distance between them should not be more than thirty centimeters. Drill the holes vertically; if the edges are inclined, you will have to re-drill them. This is time-consuming and significantly increases the installation time of the adjustable floor.
Photo - drilling a hole in plywood
Step 2. Insert threaded bushings into the holes on the bottom side, secure them with small self-tapping screws; they should not turn when adjusting the floor height. Manufacturers provide four places for fixing the bushings, so many are not needed, just secure it with two self-tapping screws.
Step 3. Make markings on the floor, try to ensure that the sheets do not have to be “shredded” into small pieces. Marking is a plan for cutting sheets. It is advisable to draw it on paper, think through several options, and only then will it be possible to choose the optimal one.
Step 4. Screw in all the plastic bolts, turn the sheet of plywood into the desired position. Screw the bolts in the same number of turns. After installing the first sheet of plywood, pay attention to what level the bolts are located. Try to screw the bolts into the next sheet of plywood in the same position.
Step 5. Using a special wrench, screw in/unscrew the bolts until the sheet of plywood is in a strictly horizontal position at the required height. Constantly check its position in several planes with a level. Very important! All bolts must have slight tension, otherwise the plywood will sag. The work is quite complex, do not make the plywood sheets large. You must reach each bolt from the concrete floor. It is very difficult to adjust the position of the plywood sheet and stand on it at the same time.
Keep in mind that the fasteners to the concrete base are not fixed; the floor turns out to be “floating”. This factor should be taken into account when deciding on the installation of flooring in each specific room.
Step 6. After installing the last sheet of plywood, check the position of the subfloor again. Remember that the adjustment parameters do not exceed 2÷3 centimeters. If concrete base If the surface has too many uneven surfaces, it will have to be leveled first. Plywood should only be waterproof.
Do not use chipboard, OSB or other materials instead of high-strength plywood, although some manufacturers give such recommendations. Pressed materials react very poorly to point multidirectional forces; in these places they quickly lose their original load-bearing capacity. Namely, such loads are present in the places where the plates are adjusted. Even though plywood costs much more, its price will pay off during the operation of the floor.
| Name | Size | Variety | price, rub. |
|---|---|---|---|
| FC plywood, unsanded | 4x1525x1525 mm | 4/4 | RUB 247.00/pcs. |
| FC plywood, unsanded | 6x1525x1525 mm | 4/4 | RUB 318.00/piece |
| FC plywood, unsanded | 8x1525x1525 mm | 4/4 | RUB 448.00/piece |
| FC plywood, unsanded | 10x1525x1525 mm | 4/4 | RUB 560.00/piece |
| FC plywood, unsanded | 15x1525x1525 mm | 4/4 | RUB 738.00/pcs. |
| Unsanded FSF plywood | 9x1220x2440 mm | 3/3 | RUB 1,048.00/piece |
| Unsanded FSF plywood | 12x1220x2440 mm | 3/3 | RUB 1,345.00/piece |
anchors for sheet materials
And the main advice in conclusion. Use adjustable flooring options only as a last resort. Practice shows that the number of disadvantages of such structures exceeds the number of advantages. The cost of adjustable joists alone can exceed the total cost of flooring made in the usual traditional way. Decide what is faster to do: lay several joists at once or drill dozens of holes in them and then “screw them in” with bolts and nuts.
Adjustable joist supports are one of the most simple ways leveling the subfloor. Thanks to this technology, it is possible to avoid “wet” work associated with pouring screed. This allows you to lay the finishing coating on the subfloor immediately after installing the wooden sheathing made of joists and particle boards. The article will discuss the main types of supports suitable for adjusting the height of floor beams, as well as the features of their use.
To level the subfloor, not so long ago they began to use not only screeds, but also logs on adjustable supports. What is the operating principle of this design? Anchor devices with a screw mechanism, which can be adjusted in height, are attached to the base material. After this, the floor beams are aligned so as to achieve maximum horizontalness of the wooden sheathing.
In the process of leveling floors, supports of various types and materials can be used. They can be attached to the following types of bases:
Installing such systems yourself is not advisable, since it involves precise height adjustment of the beams. This effect can only be achieved using professional devices. Unevenness of the floor leads to a violation of the geometry of the finishing coating, which can lead to its deformation.
Compared to other methods of leveling floors, logs that can be varied in height have a number of advantages, namely:
When arranging the floor with your own hands, you can use several various designs with adjustable lags. Each of them has its own advantages and disadvantages. The most popular “jacking” systems include:
To buy a quality kit, first of all, you need to check the quality of the supports themselves. The threads on them should be smooth without any damage. Otherwise it will not be possible to set the desired height lag, which is fraught with distortions.
Arranging a subfloor using “jacking” systems involves the use of special threaded supports. They are conventionally divided into two large categories:
Types of supports by type of construction What types of racks are best to use to level the floor with joists? When arranging “jacking” wooden battens, they can be used Various types
Stands with automatic height adjustment.
To install floors using adjustable beams, you don't have to buy expensive post bolts. Knowing already some of the features of the system that were discussed above, it will not be difficult to make similar devices yourself. To assemble adjustable anchors you will need:
Assembling the screw support for leveling the floor:
An adjustable plywood floor can be raised to heights of 3-5 cm or 15-19 cm, depending on the designs of adjustable supports used. If you need to raise the floor to a small height of 3-5 cm, and it is impossible or impossible to arrange a floor screed according to the permitted load, an adjustable floor is made from plywood with plastic racks. To lift to a height of up to 19 cm, steel studs with supporting washers are used to support the plywood.
The design of an adjustable plywood floor does not require the use of wooden joists, and the adjustable bushings are screwed directly into the plywood (plastic bushings) or pass through the plywood (metal support studs).
The adjustable plywood floor on plastic studs can be raised to a height of 3 to 5 cm. This is enough for laying under the floor engineering communications plumbing, low-current and power electrical wiring.
For an adjustable plywood floor, moisture-resistant plywood with a thickness of 12 mm is used. Plywood is laid in two layers with offset. The first layer of plywood is directly adjustable in height using bushings, the second layer strengthens the floor structure.
The floor level is adjusted using a plastic post bolt and a bushing inserted into a hole in the plywood. 13 holes are made on a sheet of plywood measuring 1525x1525.
When calculating the finished floor level, the following are taken into account:
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A metal pin can be used to support the plywood sheets.
