How to strengthen sexual lags: methods and technology for performing the work. How can you strengthen the second floor joists? Methods of strengthening and stages of work How to strengthen the floor of the 2nd floor

For modern technologies In the construction and renovation of low-rise buildings, the use of techniques for strengthening second-floor structures is used quite often. Thanks to the accumulated experience and the use of new materials and technologies, many works, including strengthening the second floor joists, have become one of the ordinary operations of repair and restoration work. However, even with this seemingly emerging simplicity, the process requires detailed study and calculation of literally all parameters and operations and selection of the optimal method of carrying out the work.

Beams and logs: what is common and what is the difference between these concepts

In private low-rise housing construction two-story houses are quite widespread. As a rule, these are houses of separate two- and three-story projects and buildings converted by arrangement attic floor. In any case, such houses are equipped with an interfloor ceiling and flooring on the second floor.

For houses built using frame-panel technology, and, in fact, all other buildings, except those where reinforced concrete slabs are used as interfloor floors, the basis of the structure is beams and floor joists.

Beams used as load-bearing ceiling structures , the ceiling itself and the base for installing the floor joists. And here lags- these are nothing more than beams of reduced size on which the plank flooring and the finished floor of the second floor or attic itself are attached.

Floor beams are usually installed perpendicular to the internal load-bearing wall; the beams are supported by the external load-bearing wall of the house and the internal load-bearing wall or pier.

The second floor joists are laid perpendicular to the interfloor floor beams. They can be laid directly on beams or have an additional structure that forms an additional volume of interfloor flooring.

As beams usually used:

Solid wooden beams;

Wooden beams;

Metal beams made of T-beams, channels, pipes or I-beams;

Metal beams in the form of composite trusses;

Reinforced concrete beams from structures of different profiles;

As lag floors are usually used:

Wooden beams;

Beams made of glued laminated structures;

Combined structures made of metal and wood;

Thus, despite the general similarity and the same principle of use in the construction of a building, beams and logs have different purposes, sizes and, accordingly, different, although in many ways similar, methods of amplification.

In the classic case of using interfloor beams and floor joists on the second floor, the structure will look like this:

Solid wood floor beams, rectangular shape, without joints (the cross-section depends on the length of the span - the width of the room) are the basis for the design of the interfloor ceiling;
The ends of the beams are fixed into an array of opposite load-bearing walls and fixed with metal studs or with self-tapping screws and metal perforated fasteners;
The second floor floor joists are installed on top of the beams. They are installed perpendicular to the beams at the same distance and have a shape and cross-section that ensure reliable fastening finished floor boards;
The space between the beams and joists is filled with insulation for noise and heat insulation of the premises.

Interfloor slab design

In this design, designed for a payload of 400-450 kg per 1 square meter, a deflection deformation of 1/300 of the beam length is considered natural. Simply put, with a beam length of 6 meters, the maximum deflection of the beam can be about 2 cm . If the beam bends to a greater extent, the structure requires additional reinforcement and strengthening.

The beams themselves can withstand two types of load: the first is the static load from the weight of the remaining floor elements and the furniture and equipment installed on them. The second - dynamic load - arises from the movement of people along the floor surface of the second floor and the temporary installation of furniture in the central part, when beams and joists have the greatest load.

Withstand different kinds correctly selected materials, their quality, and installation method, including the distance between beams and joists, help the interfloor structure to resist loads and not succumb to deformation.

Dependence (in millimeters) of joist sections and steps between them on the thickness of the floorboards

Considered optimal I-beam shape of composite joists for floor and composite form of beams for interfloor coverings. At the same time, for any types of logs and beams, the main type of deformation affecting the entire structure of the house is the deflection in the central part. And that is why beams and joists located in the center are most often reinforced.

When it is necessary to strengthen the logs

In construction practice, reinforcement of second floor joists is used in several cases, most often at the stage of construction and reconstruction of a building. At the construction stage, it is easier and more convenient to do reinforcement, especially since several methods can be used for this, choosing the most suitable one. During reconstruction, reinforcement can be done after complete or partial dismantling of the floor covering and insulation, while there are very few methods for installing additional structures.

Strengthening work is usually carried out:

To prevent deformation interfloor beams and floors of the second floor during construction;

To correct defects made during the construction process and identified during the construction of the building;

To replace wooden building structures that are deformed or damaged by natural pests or structures made of other materials as a result of exposure to third-party factors.

To strengthen the joists when repairing the floor.

Methods and methods for strengthening the structure in such cases are selected depending on the volume of work and the degree of deformation of the floor and the interfloor ceiling itself. In some cases, simply strengthening the joists will not have the desired effect without significant work to restore the beams, because, having leveled the floor of the second floor, sooner or later the ceiling of the first floor will have to be leveled.

When assessing the floor, you need to objectively assess its condition, because in many cases it is necessary to replace deformed floor boards or level them, rather than strengthen the joists.

This method is applicable for strengthening the floor structure of the second floor, when the beams do not have a deflection, and the logs themselves, based on calculations, can withstand the design load. The essence of this method is to install additional logs in the central part of the room, thus ensuring the distribution of the load more evenly, over a larger number of supports.

Most often, installation of additional logs is carried out in the center of the room by reducing the distance between the logs by 25-30%. So, if it is necessary to install logs every 0.5 meters, in the central part the distance is reduced to 0.4 - 0.35 meters.

For reinforcement, standard logs used in the structure are used. For strength, additional spacers made of solid pieces of boards or metal are installed between the joists. bar prostheses, installed crosswise.

Rod metal prostheses for strengthening joists

The method of installing additional overlays and reinforcing the joists is possible both at the construction stage and during repair work. For timber logs, reinforcement is most often used with wooden overlays and plywood overlays or OSB boards.

Wooden overlays are used:

To strengthen mechanically damaged areas of lag;

To strengthen the joint or joint of the log;

To create additional strength along the entire length of the joist.

a, b, c - reinforcement of joists with wooden overlays on bolts, d - reinforcement with rod prosthesis

Overlays made of OSB boards and plywood are mainly used at the places where sections join each other and in places where defects are visible or there are minor mechanical damages.

Metal plates can be applied to areas of damage and joints as a method of local solution to the problem.

Full reinforcement with overlays

Installation of overlays on joists along the entire length is carried out using a bolted connection through the body of the overlays and the joist, using self-tapping screws along the entire length or using a bundle with several bundles of mounting wire.

Installation of the linings is carried out alternately with temporary fixation of the linings using clamps or self-tapping screws to the body of the log.

Holes are drilled along one line. The distance between the connection holes is usually no less than ¼ of the log length. The holes are drilled like this: one in the center, and from the edges at a distance of 1/3 of the log height from the edges of the log. This arrangement of holes will not allow beams and joists to split along their length. Bolts must have washers on both sides - both under the bolt head and under the nut. The tightening is carried out gradually, until the wood has significant resistance, and the final tightening is done one by one, starting with the outer bolts. In this case, the tightening is done evenly by ¼ turn.

If the logs have edges fixed in brick wall, a hole must be made so that the edges of the beams are also fixed in the wall. Additional beams are treated with an antiseptic before installation on the joists.

If it is necessary to straighten sagging joists, use wooden wedges or a regular car hydraulic jack, pressing the lag to the desired level.

Local reinforcement of joist structures is used mainly at joints or joints of joists. To strengthen these areas, the method of installing overlays on one side or installing overlays on both sides of the beams is used. For the one-sided method, wood without knots and visible damage is used, in which case the width and height of the additional element must be equal to the width and height of the log itself.

Partial reinforcement of joists (on both sides) at joist joints

Fixation is carried out using bolts, screws and nails. The length of the element must not be less distance between two floor beams. Bolted connections are made through, the washers should be 3 times wider than the nut and bolt head.

Reinforcing the joists with a wooden overlay

To fix the joint of the joists with double-sided overlays, it is allowed to use a beam narrower than the joist. Typically, boards 1/2 the width of the joist are used for this. The length of the overlays is usually taken to be at least 1 meter. The screed is also done using bolts or self-tapping screws.

For logs made of glued material or structural wooden I-beams, overlays made of plywood or OSB boards are most often used. Such overlays are also installed in the form of double-sided overlays or one-sided lag reinforcement. This connection is fixed using self-tapping screws. The thickness of the plywood element or OSB board element should be no less than 10-12 mm. The size of the overlay for a structural I-beam must correspond to the height of the central part.

Reinforcing joists with plywood

Fixation with self-tapping screws is done on both sides of the linings. It is important that the screws pass through the thickness of all elements being fastened.

Metal linings used to strengthen the joists of second-floor houses can be:

Piece elements made of perforated sheet metal thickness of at least 5 mm;

Made from metal strips of various widths with a thickness of at least 5 mm;

From a shaped pipe, square or rectangular section with perforation or welded fasteners;

From a corner or brand.

Piece elements made of sheet metal are used to reinforce joist joints. The dimensions of such overlays can be either standard or selected depending on the specific connection case. Fixation for beam joints small height is carried out using self-tapping screws, and if the logs have a height of more than 10 m, then using a bolted connection. Metal plates are used for double-sided installation.

Reinforcement of logs with steel sheets

Metal strip usually reinforces long logs, and if the width of the strip used for installation is greater than or equal to 50 mm, then fixation can be either using self-tapping screws or bolts.

Reinforcement of logs with metal strips and channels on both sides

For logs that need to be strengthened along the entire length, they are used as structural elements. shaped metal pipes square or rectangular section. The installation location for such elements is the central joists of the premises, where the defects are most pronounced. The pipes are simply fixed to the joists along their entire length on one or both sides. Bolts are used to tighten reinforcement beams with a height of 80 millimeters or more. For smaller lags, fixation is carried out using self-tapping screws.

Shaped metal pipes can be used for reinforcement wooden logs

Corners most often used for installation at the bottom of the log, strengthening it from deflection on the bottom side. To do this, corners measuring 30*30, 45*45 or 60*60 mm are inserted under the joists from below and fastened with self-tapping screws into holes drilled in the corner.

Reinforcing joists with corners

Taurus of various sizes can be attached both to the side and to the bottom of the joist. The fastening method depends on the width and height of the joist.

The use of metal for installing logs has found its application relatively recently. Mainly metal structures low-rise construction used as interfloor floor beams. At the same time, T-beams, channels and I-beams are quite often used as a base for fastening wooden elements and serve as excellent lags for the finished floor.

The nature of changes and deformations in such structures, as a rule, does not differ from wooden logs - deflection in the central part of the room is also typical for metal elements.

Methods for strengthening such structures depend on how much space can be used for installation additional elements. If there are interfloor beams under the metal joists, then the following methods can be used:

Installation of additional structures in the form of trusses;

Raising the sagging area and installing an additional support stand under it;

Installation of additional logs from a more stable form of rolled metal.

Installation additional design in the form trusses made of pipes, angles or fittings will ensure the rigidity and reliability of the lag. For this purpose, triangular or rectangular trusses with diagonal stiffeners are used.

If it is possible to strengthen the place of deformation with a stand under the place of greatest deflection additional rack supported by an interfloor beam, then this method will provide the simplest and most effective method of reinforcement. True, it must be borne in mind that the floor beams must withstand the loads from such reinforcement.

How can you strengthen the second floor logs?

When organizing wooden floors Logs are often used, especially for rooms located on the 1st floor. They can be made of wood, reinforced concrete, metal, etc.

What are wooden joists

The logs represent cross beams, which are installed on bricks or reinforced concrete base. They are made from solid wooden beams of square or round cross-section. To save money, some owners make them from spliced boards mounted on edge.

Floors organized on logs

Advantages of using decking on joists

At the same lifting height, floors organized using joists have a much lower structural weight, for example, compared to reinforced concrete ones.
The floor, organized in this way, is well ventilated.
Hidden communications can be installed between the flooring beams.
The floor, which has free space under the flooring, can be additionally insulated and soundproofed.
Such floors can be leveled even if they have a large difference in height.
A floor that has this design can be easily dismantled for restoration.

In order for the floors to be reliable and last a long time, the cross-section of the beams must be correctly calculated. To do this, you can use special tables.

Beam section calculation table

However, situations arise when floors need to be reinforced. This happens in the following cases:

the load on the floor increases, for example, due to the conversion of an attic into an attic;
damage to the load-bearing wooden elements from which the floor was made by fungal diseases or due to damage by rodents;
exceeding the load-bearing capacity for which the floor was originally designed;
initial incorrect calculation of the cross-section of wooden elements, etc.

Attention! It is allowed for the floor to have a deflection of 1:300. That is, if the beam is 3 meters long and the deflection is 10 mm, then this is an acceptable value and no reinforcement is required.

There are several ways to strengthen the lag. Let's look at some of them.

We strengthen the floor by reinforcing wooden structures with overlays

This is carried out if cracks are found in wooden structures or the floor begins to sag significantly.

Before carrying out work, it is necessary to unload the floors, and it may also be necessary to dismantle the covering. Unloading the structure is carried out by installing temporary racks made of logs, timber or jacks. The number of racks and their cross-section depend on the length of the span of the structure and the load.

If the logs are made of solid log, it is allowed to install a single post at the point of deflection. If the structures are composite, then you need to install several racks. In the place where the floors sag, install a jack, and with its help bring the system into a horizontal position.

If the floor sagged due to the fact that a beam of a smaller diameter than required was initially used, then, using the table, calculate the required diameter. Next from desired value subtract the diameter of the beam. The resulting value will give us minimum thickness overlay, which is used to build up the beam.

The overlay is installed on one or both sides and stitched together old design using bolts with metal backings. They are needed to prevent the wood from collapsing under load at the attachment point.

To strengthen the floor, you can use metal overlays instead of wooden ones. In this case, metal strips with a thickness of 10 mm and a width 10–20% less than the width of the log are used. As in the case of wooden overlays, metal ones are installed on one or both sides of the structural element, only the number of fasteners is increased by approximately 25%. The metal is treated with anti-corrosion compounds before installation.

If reinforcement is performed when the beam is damaged, then it is necessary to install a support, remove the damaged area, and treat this area with antifungal compounds. The linings themselves are also treated with an antifungal compound.

Reinforcing beams with wooden overlays

Reinforcement can be done using carbon fiber, which is used if the beam is not damaged by fungus, but cracks have appeared in it.

In this case, the damaged part is wrapped in carbon fiber, which is fixed using a special adhesive composition made on the basis epoxy resin. This material allows you to strengthen the structure without increasing the thickness of the reinforced element. A 1–5 mm layer of carbon fiber is wound onto the desired location, depending on the expected load and condition of the beam.

Once finished renovation work, the supports are removed.

Strengthening wooden beams using prosthetics

If the timber is damaged by fungus or insects, then the floors can be repaired by strengthening the structure with the help of prosthetics. The prosthesis is a special small metal truss that is installed in place of the damaged area.

Prostheses are made from channel bars or welded using metal rods. For repairs on your own, in this case it is better to use a channel, since it is produced standard sizes, and you just need to choose a suitable prosthesis. Thanks to its shape, the channel perfectly withstands existing floor loads.

Attention! To make a prosthesis from metal rods, it is necessary to perform a rather complex strength calculation, and therefore it is better to entrust this matter to a specialist.

To strengthen the floors, prosthetics made from channel or metal rods are used

Damage often occurs in the part of the beam that rests on the wall, since it is in this place that the logs are exposed to sudden temperature fluctuations and high humidity. If this part of the structure is damaged, then a system of wooden and metal prostheses is used to strengthen the floors.

Before starting work to strengthen the structure, the damaged element is supported with supports. The damaged area is cut out. The cut is treated with antibacterial compounds.

Next, wooden overlays are selected so that the total thickness of the structure is slightly greater than the thickness of the original structure. An insert is inserted between the pads. The liner is fixed to the linings using nails.

Strengthening the structure with a wooden prosthesis

We strengthen the floors between floors

To strengthen the floors that are located between floors, you can install additional supports from below, which will take part of the load upon themselves. In this case, the floors will be able to bear a greater load.

If possible, additional intermediate beams can be installed. This will also strengthen the floors.
If possible, you can install additional intermediate logs.

If it is not possible to strengthen the beam using the above methods, then you can unload the structures by redistributing the load to additionally installed elements.

Currently, there are a huge number of different construction manuals (" We build a house with our own hands", "How to build good house", etc.). They offer various materials and technology.

If we talk about family living, then the most the best option counts two-story wooden house. Wood is an environmentally friendly, healthy material, easy to process. It is used not only for building walls. Wood is a popular material for flooring. We'll talk about them in the article.

Lags

IN wooden house use beams or joists to construct floors. However, the latter are more popular. This is due to the fact that floor joists are much lighter than beams and are more mobile.

It is extremely difficult to move beams after installation, and repairs will be very expensive. Floor joists are easy to install, dismantle and repair.

Specifications

If we build a house with your own hands, you need to know some technical details. First of all, you should choose the right material in size. The table below shows the parameters (in millimeters) that should be followed:

Board thickness	Step between joists	span of room	Lag section

To better understand the calculations, consider an example. Let's say the length of the room is 10 m, and batten has a thickness of 30 mm.

In accordance with the data in the table, for such a thickness it should be 50 cm. For a room of a given length, 20 logs are needed. In this case, the distance from the wall should not be more than 30 cm. Accordingly, you need to add 1 more log to 20. The distance between the others will be 45 cm.

Important point

When calculating, rounding should be done downward. This will provide an additional margin of safety.

There is no need to calculate distances to the nearest millimeter. As a rule, centimeters are used in calculations.

Grounds

Before how to do wooden floor , it is necessary to assess the condition of the foundation.

The logs can be laid on concrete, wood or ground. Each option has its own technological features which should be taken into account when performing work. In general, flooring technology remains virtually unchanged.

Wooden base: preparatory stage

It can be OSB boards or Under the future wood flooring You can lay insulation with vapor and waterproofing. Polystyrene foam or mineral wool is used.

Before how to make a wooden floor, it is necessary to take the dimensions of the room. The amount of material is calculated taking into account the parameters given in the table above. Next, materials and tools are prepared and markings are made.

At this stage, the main thing is not to rush. Mistakes made during preparation are extremely difficult to correct later.

Installation

Wooden logs begin to be installed from the wall (outer) ones. If the room already has a subfloor, then you can attach it directly to it. Fixation should be carried out using metal corners with perforation. These fasteners greatly facilitate the work and ensure the stability of the lag.

According to the mark, taking into account the size of the board that will be used subsequently, a log should be attached. Do not tighten the screws immediately until they stop. Adjustment may be required later.

After installing the wall elements, you can begin installing the intermediate ones. The step between them will depend on the thickness of the board. Typically the distance is 70 cm.

Alignment

It is necessary to stretch a rope between the wall joists. The remaining intermediate elements are installed at this level. The accuracy should be ± 1-2 mm.

There is no point in leveling with greater accuracy, since it will take quite a lot of time. The height difference can be removed later when finishing the front part of the wooden flooring.

Ventilated floors

They are mounted according to As a rule, this option is used in non-residential rooms.

When installing such floors, special precision is not required. Leveling is done directly with lags. Fastening is carried out using nails or self-tapping screws from the side of the beams. The scheme of actions does not differ from that described above.

Ventilation is carried out through special openings in the foundation. A distance of at least half a meter should be maintained between the floor and the ground. If it is less, the shortness of air exchange will not meet the required parameters. This, in turn, will negatively affect the condition of wooden structures.

Concrete base

The installation of a floor on it is associated with a number of difficulties. First of all, it is necessary to reliably protect the wood from rotting. For this, all kinds of impregnations are used. Meanwhile soaked special compounds structures can hardly be considered environmentally friendly, but it is precisely because of this indicator that many use wood in construction.

If it is planned to install logs over the entire area, between them there are mandatory waterproofing is installed.

To fasten the elements, the same metal corners. They provide a gap between the concrete and the joist. Of course, the load-bearing properties of the base will deteriorate somewhat.

Work progress

Markings are made along the concrete screed. Use a drill with a Pobedit drill to make holes for the corners. The distance will depend on the size of the lag.

The two opposite ends of the wooden element are set according to the level and marks, then they are attached to the corners. To check the position is used building level. Other lags should also be set according to it.

This installation option has a number of undoubted advantages. First of all, direct contact between wood and concrete is completely excluded. Secondly, with the help of corners you can remove unevenness up to several centimeters. Accordingly, there is no need to do a finishing screed before installation.

You can, of course, lay the logs directly on the concrete. In this case, a material based on modified bitumen is used as insulation.

Ground mounting

This method of laying lags is usually used in outbuildings, bathhouses, gazebos, etc. Wood must be treated with antiseptics. If you need to make it durable strip foundation, then you need to provide ventilation vents in advance. Usually a columnar base is used.

Before laying the logs, it is necessary to remove the fertile layer of soil. Next, the columns are marked. They can be made of concrete, prefabricated, block. The size of the supports is approximately 40x40 cm, the depth is 30 cm. Sand is poured onto the bottom in a layer of approximately 10 cm and compacted.

The next stage is pouring the supports with concrete. The mixture is prepared from a ratio of 1 part cement to 3 parts sand and 2 parts crushed stone. It is not necessary to make formwork in the ground. Formwork made from scraps of OSB or boards is fixed above the ground. When constructing it, a level must be used. The edges of the formwork must be vertical.

The easiest way to make columns is from blocks. They are leveled horizontally using a rope. After installing the outer posts along the hydraulic level, you should pull a rope between them. It is necessary to ensure that the deviations are not more than ± 1 cm. This difference can then be eliminated when installing the log.

Installation Features

Laying also begins with the outermost joists. Precise horizontal alignment can be achieved using shims. It is not recommended to use wooden wedges as they will shrink over time and wobble will appear: the floor will creak while walking.

Between wooden elements And concrete surfaces Roofing felt is laid in 2 layers. This will ensure reliable protection from moisture.

After installing the outermost joists, the installation of the rest begins. Alignment is carried out along the rope. Fixation is carried out using metal corners and dowels with self-tapping screws. You can increase stability by installing fasteners on both sides.

The boards can be laid directly on the joists or on the subfloor.

Coniferous wood is considered the best option.

You need to select logs with a margin of safety. This is especially true if it is planned to install an interfloor wooden floor. In such cases, the elements will bear increased bending load.

It must be remembered that the mistakes that were made on preparatory stages, fixing it later is much more difficult: you will have to spend not only time, but also money. Therefore, it is more advisable to immediately choose quality materials and follow the recommendations.

When choosing lags, it is necessary to evaluate their condition. The wood should not show signs of rotting, through cracks, or knots.

Consequences of errors

As mentioned above, failure to comply with the technology can lead to wobbly boards. And if it is still possible to correct such errors on the ground floor, albeit at a financial cost, then repairs second floor ceilings- a real problem.

In many homes, especially old building, you can notice the deflection of the ceiling with the naked eye. This situation is associated with incorrect calculation bearing capacity of structures or exceeding the maximum load.

The amount of lag deflection depends on various factors:

Quality of the material.
Wood moisture level.
Insufficient thickness of metal elements.

These, of course, are not all the reasons. In some cases it is laid under load.

It should be said that in any case, sagging ceilings can have the most Negative consequences. Incorrect calculation of the load can lead not only to the deflection of wooden elements, but also to the complete collapse of the second floor in a wooden house. And this happens, as a rule, when no one expected it.

When should action be taken?

Which one needs to be carried out? preparatory work, before How to strengthen the second floor joists? Can strengthen the ceiling if obvious sagging of the ceiling is detected. In this case, the first thing that needs to be done is to take measurements, assess the condition of the structural elements, and determine the static load indicator. Using these parameters, the amount of sagging is determined.

Any ceiling, under the influence of its weight, the static load of objects and structures installed on it, bends over time. The acceptable sag value is 1:300. For example, if a beam 3 m long bent by 10 cm, there is nothing to worry about yet. However, if the value is greater, you need to carry out strengthening of structures and get rid of deformations. Next, we'll look at several ways to fix the problem.

How can you strengthen the second floor joists?

Methods for strengthening wooden structures vary depending on the condition of the elements. Everything can be found in construction stores.

The first, fairly simple way is to use timber overlays. The width of the beam is subtracted from the cross-section of the log. The elements are fastened with bolts with metal plates, which prevent the destruction of wood in the connection area.

The bent log is raised to the required level, after which the timber lining is fixed to it.

Metal strips

Their thickness should be 10 mm, and their width should be 10-20% less than the height of the logs.

Bolts should be used for fastening. At the same time, to increase the strength of the structure and prevent deformation of the strip, it is advisable to increase their number.

Overlays can be installed on one or both sides at once. This will depend on the load on the load-bearing parts of the floor.

Other metal products

How can you strengthen the second floor logs? if they are damaged by putrefactive bacteria or insects?

To strengthen the elements, “prostheses” are used, welded from a rod in the form of a spatial truss or using a channel.

In the first case, a rather complex calculation of the strength indicator is required. It can only be carried out by a qualified specialist. The channel can be selected from standard rolled metal products.

Additionally

Gain interfloor structures can be done by installing additional logs. However, such work will require adding holes in load-bearing walls. In some cases, making them is very problematic.

When using metal elements to strengthen the logs, it is necessary to provide for the installation of elements to which the boards will be attached. They must be reliable and durable, eliminating wobble. This is especially true for floors with damaged parts.

Use of carbon fiber

It's comparative new way lag reinforcement Carbon fiber is glued in several layers until the required rigidity of the log is achieved.

This material is presented on the market in the form of fabric, threads, plates, tapes, sheets. Carbon fiber (CFRP) is very convenient to use. One of its advantages is its light weight.

Installation of a rod “prosthesis”

To manufacture this element, two paired trusses are used. They, in turn, are made from scraps of reinforcement with a cross-section of 10-25 mm. The length of the product must exceed twice the length of the damaged end of the joist by 10%, but be no more than 1.2 m.

Installation is carried out as follows:

Temporary supports are installed in increments of 1-1.5 meters from the load-bearing wall. The supports are racks with purlins.
The damaged section of the joist is cut off.
The “prosthesis” blank is inserted vertically into the interfloor ceiling and turned over horizontally. First it is pushed onto the log, then into reverse side and push it into the wall niche.
The sliding bar is moved to the required distance and fixed.

Alternative material

At the very beginning of the article it was said that for the construction of floors it is more advisable to use logs due to their mobility and lightness. This recommendation can be used if the expected load on the structure is small.

But what to do if the load indicator is high? You can deal with the problem using wooden I-beams. Outwardly they look like rails.

Scope of use

Wooden I-beams used in private construction. In low-rise buildings, these elements are used as load-bearing structures in interfloor ceilings.

I-beams perfectly replace boards, metal profiles, reinforced concrete slabs. They are able to more than triple the rigidity of walls. The result is a more stable structure without a significant increase in weight.

Characteristics

For the manufacture of I-beams, glued laminated timber and particle board are used. The photo above shows the design features.

Among the features of the I-beam are the following:

The plywood used for the side posts is moisture resistant. The thickness of the plate can be different: from 24 to 27 mm. The I-beam contains wooden shelf, treated with an antiseptic.
Inserting a stand from particle board carried out using special technological grooves.
The parts are fixed to each other using water-heat-resistant glue.
The outside of the I-beam is coated with water-repellent paint.

The following dimensions are considered the most common: dimensions - 200x80 mm, lintel thickness - 27 mm.

Advantages

First of all, it should be noted good combination materials: wood - slab - wood. The design does not have the disadvantages inherent in natural wood.

The I-section acts as a kind of amplifier: due to it, the strength of the jumper increases several times. These features make it possible to place the I-beam on a par with concrete and metal floors. At the same time, beams have a significant advantage over the latter, since they are not at all susceptible to corrosion.

When installed in accordance with the technology, the floor will not creak. does not bend, unlike logs and other wooden materials.

Despite the operational power, the weight of the jumper is relatively light. Installation of structures can be done with your own hands. Installation of I-beams can be carried out by 2-3 workers. The weight of the product with a length of 6.5 meters does not exceed an average of 40 kg. Accordingly, the foundation of the building will not be under high load.

I-beams are not subject to drying out. Due to High Quality manufacturing, deformation of the beam is practically eliminated. In addition, the elements do not shrink, swell, or twist under the influence of climatic factors.

The ability to retain heat is of no small importance. Beams have low thermal conductivity, which helps reduce cold bridges.

For the manufacture of I-beams it is used the latest equipment And Hi-tech. The products fully comply with international and national quality standards. At the factory, beams are treated not only with an antiseptic, but also with a fire-fighting compound.

I-beams can be used in low-rise buildings of any type, including frame and block houses. Mounting can be done using any accessible ways. As a rule, metal fasteners, screws, bolts, angles, and brackets are used.

As you can see, beams are an excellent alternative to joists. Having installed them, the home owner will not worry about sagging ceilings and creaking floors.

One of the main structural elements used for the construction of floors in attics or second-floor rooms, mainly in low-rise buildings individual construction, is wooden or metal beam, which simultaneously performs the functions of floor joists and the basis for attaching ceiling coverings. Widespread beam floors contributed to the low cost of the initial building materials and the possibility of constructing floors without the use of lifting mechanisms.

Lag deflection

Often the degree of deflection of the joists depends on the installation technology and the quality of the material.

Entering some, especially old, houses, even with the naked eye you can notice the deflection of the ceilings of the second, or, less often, the floor of the first floor, which is a consequence of incorrect calculation of the load-bearing capacity of the joists or excess permissible load on the floors. As the practice of operating multi-storey buildings built in the first half of the 50s of the twentieth century, where wooden interfloor ceilings were used, suggests, by the year 2000 the ceiling deflection ranged from 70 to 100 mm, which led to the need for major repairs buildings with reinforcement of load-bearing floor elements. And this is provided that an accurate engineering calculation of loads and lag sections is carried out at the design stage. And what can we say about individual development, when the calculation of the load-bearing capacity of the logs was carried out “by eye” on the advice of “competent” specialists.

Very often, the quality of the material used also influences the amount of deflection of the logs, excess humidity wood, insufficient thickness of the rolled metal from which the beam is made, and many other different reasons leading to sagging, for example, of the second floor floor under load. An incorrect calculation of the load-bearing capacity can lead not only to the deflection of the log, but also to the complete destruction of the structure and the collapse of the floor downwards, and when no one expects this.

When is it necessary to strengthen the logs?

Scheme of interfloor wooden floor arrangement

If the owner of the house notices sagging top floor, then the first thing that needs to be done is to carry out simple measurements and assess the condition of the structures, the magnitude of the static load, in order to determine the amount of sagging of the ceiling or changes in the curvature of the floor in order to decide on the need to strengthen the logs.

Any ceilings, under the influence of their own weight, the static load of structures and objects installed on them, sag over time. The permissible sagging value is taken to be 1:300, that is, if a three-meter beam sagged by 10 mm, there is no cause for concern, but if this value is greater, then measures must be taken to eliminate the deformation and strengthen the structure.

Strengthening metal structures

Metal structures used as interfloor beams can be strengthened with additional rolled metal products using welding or bolting. To do this, the surface of the floor or ceiling is dismantled, if necessary, adjustable supports are placed under the floor beams to eliminate deformation, and the structure is reinforced with standard rolled metal products of the required cross-section, the calculation of which is carried out using special tables and methods.

Strengthening wooden elements

An example of reinforcing a joist with a wooden overlay

Depending on their condition, existing structural elements of a wooden floor can be strengthened in several ways:

Using timber overlays, performing a simple mathematical calculation, when the width of the existing beam is subtracted from the table value of the cross-section of the required floor beam. The timber and the beam are fastened using bolts with metal plates that prevent the destruction of the wood at the fastening point and weakening of the structure. The existing beam is raised with jacks until a level floor surface is obtained, after which the overlay and the beam are fastened together;
Using metal strips 10 mm thick and 10-20% wide as overlays less height timber. To prevent the strip from deforming and reducing strength, the number of fastening bolts should be increased by 25% compared to wooden elements. Overlays are installed on one or both sides of the beam, depending on the load on the load-bearing elements of the floor of the upper floor;
Wooden floor beams damaged by insects or putrefactive bacteria can be strengthened using prosthetics welded from a rod in the form of a spatial truss, or using a channel of the required size. The channel installed as a prosthesis is selected from a standard range of rolled metal, and to manufacture a spatial rod truss it is necessary to perform a rather complex strength calculation, which only a qualified specialist can do.
Strengthening the load-bearing capacity of interfloor structures can be done by installing an additional number of beams, but this work requires making holes in the load-bearing walls, which in some cases is difficult to do.

Reinforcement of logs with metal strips

Using metal elements To strengthen the load-bearing interfloor structures, especially for destroyed parts that need to be removed, it is necessary to provide for the installation of elements on which the floorboards of the upper floor will be fixed. The fastening must be reliable and durable, eliminating the possibility of loosening and squeaks.

Reinforced different ways logs allow you to increase the load-bearing capacity of interfloor structures and general security operation of existing buildings without significant capital investments and a large volume of construction work.

In the majority wooden houses the design of floors is used, in the manufacture of which wood is also used. Beams are made from this material. Considering the significant load they must withstand, it is often necessary to strengthen the floor joists in a wooden house. This is quite simple to do if you know the features of these structures and the basic methods for performing such work.

Wooden logs - description and advantages of use

Wooden logs are beams that are installed on bottom trim log house or on bearing structures walls. For production it is almost always used solid timber, which has a square or round section. In some cases, in order to save wood, the owners of buildings decide to construct them from edge-joined boards.

The use of wooden logs in the construction of floors and floors immediately provides a number of significant advantages:

wood features allow you to get much more lightweight design at equal height, for example, with reinforced concrete slabs floors;
the structure of the floor with logs provides the possibility of ventilation, which is extremely important for effective use thermal insulation material and the durability of the wood itself;
it is easy and convenient to lay any internal communications between the beams;
the ceiling design using beams allows for additional heat and sound insulation;
using logs of different heights, you can easily even out even serious differences that arose due to errors during the construction of the log house;
the design of the floors allows any repair work to be carried out, if necessary, without serious problems and large labor costs.

Considering the number of advantages listed, it is quite logical that floors using wooden beams are the most common design solution today. This design is used for most houses made of logs or timber.

The need to strengthen wooden floor joists

Quite often it is necessary to reinforce the floor joists in a wooden house. This is explained by the owner’s desire to play it safe by making the important supporting structure as reliable as possible and able to withstand any load. Other, less pleasant reasons for performing work to strengthen beams may be:

During operation, the load on the floor increased, exceeding design parameter, taken into account during construction;
carriers wooden structures partially lost their strength characteristics due to rotting, the appearance of fungus or microorganisms;
When designing the building, mistakes were made, as a result of which the cross-section of the beams turned out to be insufficient for the normal operation of the building.

In each of the listed cases, deflections of the joists or the floor as a whole, as well as other types of deformations, may be observed. Of course, in such a situation it is necessary to strengthen the floor beams in a wooden house as quickly as possible. Otherwise, its operation will simply become unsafe for the inhabitants of the building.

Ways to strengthen wooden floor beams

When deciding whether to strengthen floor beams, two things should be taken into account: important points. Firstly, possible options performance of work. Obviously, it is extremely important to produce them in such a way as to obtain the desired bearing capacity designs, while spending a minimum amount Money and time.

Secondly, you need to understand that strengthening the logs of the second floor wooden house and beams basement floor- this is far from the same thing. Therefore, the method of performing work should be chosen taking into account the location of structures in the building.

Reinforcing joists with overlays

One of the simplest and at the same time quite reliable methods of strengthening beams is the use of wooden or metal overlays. Before performing work, it is necessary to unload the floors. To do this, temporary racks are installed, which can be constructed from timber, logs or jacks. The longer the lag, the more often it is necessary to install supports. If the ceiling has bent, you need to use racks to return it to its horizontal position.

Then the linings are made, the cross-section of which is selected based on the load exerted on the logs. When reinforcing floors, they are usually made of timber, and when working to strengthen floors, it is allowed to use steel strips with a thickness of at least 10 mm and width. The width in this case is selected slightly smaller than that of the logs. The cover is attached to one or both sides of the beam, after which it is securely fixed using bolts with steel linings.

IN Lately special carbon fiber was used to strengthen the beams. This material is effective when cracks appear in the structure. It is wrapped around the joist and secured using epoxy glue. After completion of the strengthening work, the temporary supports must be dismantled.

Strengthening floor beams using prosthetics

Under a prosthesis in construction in in this case refers to a small steel truss that can be installed in place of the damaged area wooden beam. For its manufacture, metal rods or, what is even more effective and reliable, a channel are used. Before performing work, the beams must be supported with racks, completely unloaded.

After this, the defective area is dismantled, and a prosthesis is installed in its place. It is then framed with wooden planks to create the structure. required thickness. Fulfill similar works recommended with an invitation professional builders, since they require careful calculation and accuracy.

Strengthening floor joists

One of the most simple options To strengthen the ceiling in a wooden house is to install supports that can relieve the load-bearing structures of the floor. Of course, this method can hardly be called the best, since it creates certain inconveniences and takes away some of the useful internal space. A variation of this method is the installation of intermediate beams, which is free of these disadvantages.

27/12/2017