How to properly tie a pile foundation. Tying the foundation with timber: features of technology, types and methods of connections. Tying with timber or board

Why is pile tying needed?
The process of tying timber on screw piles
- Thread fit
- Landing on clamps
Some useful tips

Do-it-yourself tying of screw piles using ordinary timber has become very popular in construction today.

To build a foundation on soft soil, especially on screw piles, strong and reliable fixation of the piles is necessary.

It is no secret that the tying process, due to its technology and labor intensity, is somewhat more complicated than the process of installing piles. Among other things, the quality of the foundation, and therefore the stability of the house itself, will depend on the quality of the piping.

Why is pile tying needed?

To better understand why strapping is needed, let’s first briefly look at the essence of a pile foundation. This type of foundation is usually erected for buildings where high weight loads are not expected in the future. At the same time, a foundation on piles is quite profitable in terms of money, since the cost of its construction is relatively cheap compared to other more reliable types of foundations. Moreover, time is saved, since a house on stilts is built much faster than other houses.

Piles are pillars firmly driven into the ground, which are located at a certain distance from each other. Even when placed on concrete, such columns by themselves cannot guarantee maximum strength and the absence of floor distortions in the house in the future. It is for this reason that strapping is required.

The tying process itself involves connecting the foundation columns together with strong, reliable materials. This will make it possible to obtain a solid foundation that will withstand permissible loads. Tying piles with timber is called a grillage and is considered one of the most reliable tyings today.

Overview of strapping installation types and selection of tools

Scheme of tying a screw foundation with timber.

So, before you start the strapping process, you need to clearly decide on the type of installation and the choice of materials and tools. Today, there are 3 most effective and reliable options for installing strapping to piles.

Threaded fit. This type of strapping is excellent for wooden piles, which are quite thick and have high wood strength. The calculation of the thread is very important here, since if the thickness of the pile is insufficient, you can easily make a mistake.

Installation of the harness using welding. This method is one of those that are mostly used for piles made of metal. The fact is that welding in this case will be practically the only win-win option, since any other strapping will not hold firmly to the metal.

Fastening the strapping to the piles using clamps. This method is considered acceptable for almost any wooden piles. And it is also great even in cases where the thickness of the piles is not too large. For some types of metal piles, clamps are also used.

So, it becomes quite clear that the specific method of attaching the strapping will directly depend on the material, quality and thickness of the pile foundation. And, of course, it depends on your specific wishes and financial capabilities.

Scheme of the device for tying the foundation of a house made of piles.

Before you start working directly with tying the screw piles with timber, you need to purchase the calculated amount of wooden beam. In order for the work to proceed quickly and efficiently, prepare the following tools:

building level;
self-tapping screws;
small anchors;
hammer;
metal corners;
roofing felt;
drying oil;
device for welding.

The process of tying timber on screw piles

Experienced builders have found that the highest quality when tying screw piles using timber is achieved by a combination of two technologies - threaded and clamped. In this case, the timber will serve for quite a long time and firmly hold the pile foundation. The only additional thing that will be required of you is to saturate the entire tree with special antiseptic solutions to prevent rotting and destruction of the wood in the future.

Thread fit

Diagram of grillage arrangement options.

We begin the strapping process by fitting onto the thread. It will be most convenient to carry out this method if the screw piles are arranged in the form of a flange (the letter P turned down). We begin the process by taking a block of the required length and placing it between 2 posts. Before this, it is extremely necessary to place small roofing felt pads oiled with drying oil on all sides of contact with the pile. In this case, the beam is attached to the side posts using self-tapping screws, and to the lower base using small anchors or through pins. After the block is secured, it is necessary to additionally knock it slightly with a hammer.

For additional strength, you can strengthen the connections at the outer corners using ordinary spikes or a small metal corner. It is best to select a corner exactly according to the size of the corner of the pile with the beam, and it is recommended to fasten it using self-tapping screws. Using this method, it will be necessary to make the strapping on absolutely all the piles, without leaving any untreated areas.

It should also be taken into account that if the piles under the foundation are installed in such a way that it is impossible to fasten small bars between them from below and along the edges (there is no flange shape), then they usually neglect the threaded connection process and proceed immediately to tying with clamps.

Landing on clamps

Scheme of cladding and finishing of the base.

The next stage of tying will be fitting onto the clamps. This whole process is as follows. Long rectangular beams will need to be placed directly on the tops of the piles. This can be done either using self-tapping screws if the piles are wooden, or by welding in the case of metal type piles. When joining, it is extremely important to ensure that the plane of the beam at the top is as level as possible. To do this, it is recommended to use a building level. We do this around the entire perimeter of the pile foundation.

After this, it will be necessary to place smaller U-shaped wooden blocks, which are usually called a clamp, between the pile beams and onto a horizontally attached beam. This is necessary for additional fixation of the result. The applied bar should point downwards. After that, these ends are fastened to adjacent pile posts using special corners or threaded connections. After fastening, the connection is checked to ensure that it does not wobble. This method is used to make the rest of the surface of the pile foundation.

Screw pile cap table.

Now it’s advisable to give a few simple tips so that the strapping is done efficiently and is minimally difficult for you. Following these simple rules and paying attention to them can guarantee your success in your future harness.

Before work, you must make sure that all piles are the same in height. This refers to the height above the ground. If some of them are lower or higher, you need to level everything right away. Otherwise, it will not be possible to achieve high-quality binding. And this will lead to curvature of the floors in the room of the future home.

When tying, make sure that when you fasten the pile to the beam, the connection with the self-tapping screw should be as central as possible. This will make the structure strong and will prevent the wood from cracking and damaging the foundation in the future.

Before you purchase timber for tying, keep in mind that the width of the wooden beam placed horizontally on the posts should be approximately 2 times the width of the pile. This will guarantee the strength and reliability of the structure.

So, the process of tying the foundation from screw piles using wooden beams can be considered complete. If you follow all the tips, it will not cause you much difficulty. The only thing you will need is patience and slow work.

Do-it-yourself tying of screw piles with timber (photo and video)

Do-it-yourself tying of screw piles with timber. The essence and types of installation of the harness. The process of tying piles with timber: fitting to threads and clamps. A few simple tips.

Pile foundations are popular in industrial and private construction when the slope at the construction site is quite large or there is a large depth of strong rocks in the area.

It is not advisable to dig deep trenches in such soils, since the soil may shift or the bottom of the trenches will be flooded with groundwater. In turn, pile structures are ideal, given their features, design characteristics and low cost in general.

What is the harness used for?

To ensure greater structural strength and uniform transfer of load from the building to the ground, a special foundation frame or grillage is often used. The grillage is connected to the piles using a hinge joint, reinforcing mesh, rigid welding and wire. In private construction, tying with a grillage made of wooden beams, corrugated pipe or channel is practiced. The harness is used:

To ensure geometrically even and correct location of all piles.
Prevent the foundation from shifting under the influence of lateral, tangential and vertical ground displacements
Ensure uniform distribution of loads from the mass of the future building through the piles to the ground.

When designing pile-grillage foundations, the number of piles must be taken into account. The more piles are used, the smaller the cross-section of the piping reinforcement will be. In addition, you can also use a regular wide board or small-diameter corrugated pipe; you need to connect all the links with corners.

Types and types of harnesses

The use of corrugated pipes for tying foundation piles of buildings

Pile-grillage foundations are highly durable; they almost completely neutralize vertical and horizontal soil movements. They are used for the construction of houses on mobile and unstable soils prone to heaving. Piles are also actively taken into account not only when designing a new house, but are also used during the renovation of an existing one, since they are strong enough and can withstand the load of buildings of several floors.

It is important to take into account the human factor, as well as the presence of hard rock in the soil. During the installation of piles, a small slope angle is inevitably formed due to the displacement of the core, so after installation of the structures they need to be leveled and strengthened.

Methods for strengthening piles used in private construction:

Tying with corrugated pipe, additional connection to the top of the pile with angles, welding or flexible wire.
The use of metal channels with different installation directions.
Use of wooden beams.

It is not necessary to do the tying at all if the location of the top point of the pile is no more than 60 cm from the ground level. But if it is higher, then it is impossible to do without strapping, since the load-bearing structures will shift even under the influence of wind or rain, and over time the building itself may become skewed.

Necessary materials for tying a pile foundation:

wooden beam, you can use thick boards;
metal channel, I-beam and connecting angle;
flexible wire, rod or reinforcement with a cross-section of up to 8 mm.

You will need a welding machine and building levels.

Channel or corrugated pipe piping

A channel is a rigid metal beam of great thickness, has its own stiffening ribs, to which reinforcement or the top of the pile are attached by welding.

A profiled pipe is cheaper, it weighs less, but it is no different in strength; the connection principle is similar to a channel. The optimal connection method is to lay two beams on top of each other or overlap. Peculiarities:

It is unacceptable to use separate beams on different piles; it must be a monolithic structure.
If the foundation is large enough, then a crane will have to be used to install and fix the channel, so this strapping method is used in the construction of warehouse and industrial buildings.
To ensure greater strength, it is recommended to use not only welding, but also bolted connections; the joints should be coated with anti-corrosion paints and checked with ultrasound.
Channels are heavy load-bearing structures, so such grillages are not used in private construction.

A channel up to 160 mm wide is used as a supporting structure, but if the pile has an outer diameter of 108 mm, then a channel with a width of 140 mm is recommended.

First, reinforcement is made with longitudinal beams, so the piles are connected to each other and create an artificial horizontal shield. Then a channel is installed on the top of the pile, which is connected by welding to the pile and additionally with angles to intermediate beams.

This design does not affect the strength of the foundation, because the channel metal, weakened by welding, has reliable support in the form of a screw metal pile, and the beams ensure uniform distribution of loads.

Tying with timber or board

This method of strengthening pile foundations is popular in private construction and is optimal for the construction of wooden buildings, bathhouses and outbuildings. The strapping steps are as follows:

First, all piles are installed at a given distance, aligned along a single vertical line so that the timber does not warp.
If it is impossible to level the load-bearing elements of the base, then recesses are made in the beams.
For joining, grooves are made, and they are always located at an angle of 90ᵒ relative to the beam. All connections are made with bolts or fairly flexible wire, and are additionally coated with anti-corrosion paint and antiseptic.

It is quite difficult to do timber tying yourself, because you need to constantly monitor the horizontality of the structure and eliminate minimal angular distortions. After installing the grillage and fixing it, the wood is coated with an antiseptic and painted to increase its service life; it is also recommended to waterproof the head with roofing felt.

Features of installing pile foundation piping

To ensure maximum strength and reliability of the structure, just connecting the beams to each other is not enough. It is also recommended to strengthen the grillage diagonally with corners and tie the supports with mortar.

If a channel or corrugated pipe is used for piping, then reinforcement from piles is produced and welded to the piping. The connection of the beams is made from wire rod or embedded T-shaped metal pins with a diameter of at least 12 mm.

In individual construction, the owner strives to save every ruble, and columnar, pile or combined foundations are increasingly in demand: the construction of such a foundation for a house or other outbuilding requires much less financial and labor costs, time, and does not require the use of special equipment. But, as in any other issue, there are difficult aspects in the construction of columnar foundations, and this is the tying of a pile foundation, that is, a kind of grillage if we are talking about concrete, and a powerful lower chord if the tying is made with a wooden beam.

Why is foundation tying necessary?

The foundation itself is much easier and faster than doing the subsequent tying with timber, metal or concrete. However, it needs to be built, and why to do this, let’s look at it in more detail. To comply with the technology, you must correctly understand the operating principle of a pile or columnar foundation. Typically, such foundations are erected for objects with a low total weight, since the load capacity of any screw pile or pillar made of any material is quite enough to support the weight of the structure. In addition, tying screw piles with timber is much more profitable financially than constructing a strip or slab foundation, and construction time takes several times less. The photo below shows a double timber frame:

A pile foundation includes several piles - depending on the total area of a private construction project, there can be from several units to several dozen. Piles can be steel pillars or reinforced concrete pipes immersed in the ground to a calculated depth, but not higher than the freezing point of the soil, that is, at least 1-1.5 meters. These pile supports hold the building above the ground surface so that the lower part of the house does not come into contact with the soil, does not absorb moisture and does not freeze from the ground.

But the columnar supports unevenly distribute the load from the weight of the building over the ground, and to prevent the house from warping, the piles are tied with a structure made of a suitable material. Such tying of a house made of timber reduces the pressure per m 2 from the mass of the object and evenly distributes the weight along the perimeter and along the internal and load-bearing walls of the house under construction.

The term “timber beam” refers to horizontal parts (wooden beam, steel angle, channel or I-beam, concrete grillage) connecting all piles or pillars to each other into a single monolithic structure. Any frame can be called a grillage, as it serves to enhance the strength and extend the life of the building.

Types and stages of strapping

The tying of the pile foundation with timber is done sequentially:

Prepare the foundation - level it and waterproof it;
Prepare the building material for the grillage;
Install the harness.

The screw piles are tied with timber or other building materials if the piles rise ≥ 0.5 m above the ground surface. The house can be not only wooden, but also built of foam, aerated concrete, hollow brick or SIP panels.

Types of strapping depending on the material of construction:

1. The grillage is assembled with beams for a wooden structure. A strong beam around the pile foundation is made with a cross-section of ≥ 150 mm and a square shape. Hardware for connections in the structure - steel pins M14-M16 or clamps made of soft thick wire. The timber must first be waterproofed and also impregnated with fire retardant and antiseptic compounds. Metal parts are protected with anti-corrosion agents;

2. A channel, angle or I-beam is attached to the piles by welding or appropriate hardware - the method of fastening depends on the material of the piles or pillars. The entire open surface of the metal grillage is coated with anti-corrosion compounds in 2-3 layers;

3. Reinforced concrete tying of piles is made prefabricated or cast in one piece. Structurally, such a frame resembles a strip foundation laid on piles or pillars. It is made for brick or block houses, but with appropriate calculations it can also be used for wooden buildings. Prefabricated framing uses beams that are laid on piles and connected to each other. To construct a solid grillage, formwork is made, into which a reinforcing frame is installed and concrete mortar is poured. The formwork is made removable (sheet materials, boards, etc.) or permanent (extruded polystyrene foam);

How to attach the harness

Before you begin tying the pile foundation, you should choose the method of assembling and fastening the grillage, as well as select the appropriate building materials.

The standard foundation piping with timber is connected to each other in two ways: a straight joint or an oblique cut. The joints are protected with an overlay of boards or a Gerber hinge. The external piping of the pile foundation is made double.

A wooden, metal and reinforced concrete grillage is attached to the piles as follows:

For threaded hardware – bolts, screws, studs;
For welding;
On clamps or staples.

Tape base

Strapping is needed not only for pile-screw and columnar foundations, but also for strip foundations, since it is difficult to attach wall beams, panels or logs to concrete. The strapping acts as an intermediate link between the material of the house and the foundation. The lumber itself is attached to the concrete using embedded reinforcement, which is installed when the foundation is poured.

Installing a wooden frame on a strip base:

The surface of the foundation must be strictly horizontal and level. The difference in height between the surface of the tape should be + / – 1 cm, so unevenness is filled with a thin screed, and smaller differences are adjusted with wooden pads;
The surface of the reinforced concrete strip must be waterproofed. To do this, use bitumen, roofing felt or thick polyethylene film. The material is laid or applied in 2-3 layers;
Holes are drilled in the timber with a diameter 1-2 mm larger than the diameter of the anchors poured into the body of the concrete strip. Each anchor is fitted with a rubber gasket and a wide steel washer, which protects the wood from deformation when the thread is tightened;
The strapping beam is laid on the waterproofing layer so that the anchors fall into the holes. The timber is connected to each other “into a bowl” or “into a claw”;
Nuts are screwed on top of the washers, and studs are not required at the connection points of the timber;
After installing the strapping belt, the assembly of the walls of the house begins.

Pile foundation

The most common methods for attaching timber frames to poles or screw piles when building a house are threaded connections and fastening with clamps. Double fastening makes the connection strong and durable, prevents the piles from loosening and distributes the load evenly across all piles. Preliminary preparation of wood before assembling the strapping consists only of impregnating the timber with antiseptic and fire-retardant compounds, and the preparation of metal parts is reduced to protecting surfaces with anti-corrosion compounds.

Sequence of tying a pile-screw base:

First, the timber frame is attached to a threaded connection to the piles. A beam of calculated length is placed between two piles, and where it contacts the metal, roofing material is laid. It is advisable to additionally impregnate the waterproofing with drying oil;
The beam is attached to the side posts with self-tapping screws, and to the bottom surface with studs or anchors;
To enhance the strength of the structure, spikes are cut into the outer corners of the beam, or the connection is strengthened by installing metal corners, which must be galvanized or coated with an anti-corrosion coating. The corner is attached to stainless steel self-tapping screws or galvanized screws;

In this way, the entire strapping structure is assembled - both on the outer sides and inside the perimeter.

If the piles are driven or screwed in the form of a flange, and it is not possible to attach beams to them on the sides, then instead of threaded connections, they are fastened with clamps: the timber is laid on the upper ends of the piles, and connected to each other with self-tapping screws. The metal grillage is held together by welding.

When connecting timber into a strapping structure, it is necessary to constantly check the horizontality of its surfaces so that during the further construction of walls they do not warp, resting on the uneven surface of the strapping. Control is carried out at the usual building level.

After connecting the timber along the perimeter of the object, it is necessary to place a structure made of timber of a smaller cross-section, connected by the letter “P”, with the ends down, between the piles on the beams located horizontally. This design is called a clamp - such a clamp can be made smaller in size than the strapping beam. With the help of these clamps, the entire harness is strengthened. During the assembly of the main frame, these wooden clamps are fastened to adjacent piles with threads or a metal angle. After assembling the harness, all connections must be checked for strength by loosening: if the structure does not move with maximum effort, the assembly is considered satisfactory.

The reliability and quality of any foundation depends primarily on strict adherence to technology at every stage of its implementation. And tying a columnar foundation with timber is no exception.

General information

Screw pile

A screw pile is a type of pile that is driven into the ground by screwing. As a rule, it is a metal pipe with blades welded to the base. These blades serve not only to immerse the structure into the ground, but also to evenly distribute the mass over a larger area of the ground.

What is a harness

After installing the screw supports, they are fastened with beams, resulting in one rigid structure called a frame or grillage.

The framing of a house is essentially the overlap between the building itself and the foundation. This design evenly distributes the weight of the house from. In addition, the grillage is the first to take on the negative effects of the environment. Therefore, it must be strong, reliable and protected from moisture.

Timber is a material made by cutting a tree trunk from four sides. It has the same cross-section along its entire length. Currently, timber is the most popular material for lining the foundation. It is especially often used in the construction of log houses, bathhouses and other wooden houses.

The bottom frame made from softwood timber is most often used, as they have some advantages over hardwood:

Higher service life and durability;
High strength;
Reduced moisture permeability;
The price is usually lower than for hardwood.

Note!
The beam for strapping must have a cross-section of at least 150x150 mm.
When purchasing material, you must ensure that there are not even the slightest cracks on it, otherwise the build quality will suffer.

Before making a grillage, it is necessary to process the material:

Antiseptic – to prevent decay and fungal development; (see article for more details)
Fire retardant, which will increase fire resistance and prevent fire. This treatment is especially relevant for pine material, since this wood contains a large amount of flammable resins.

Advice!
When calculating the amount of material, it is advisable to add 10-15 percent, since during the work it may not be enough.

Glued beams are much stronger than regular beams, and they also have more accurate dimensions. As a rule, such material has protrusions and grooves. As a result, the structure made from this is very durable.

The main advantage of laminated veneer lumber is thermal and moisture protection. The design will be tight and without gaps in the corner joints. Of course, such material costs more than regular material, but it does not need to be dried and treated with an antiseptic.

Another advantage of glued material is that it does not rot and is very light in itself. Thus, a grillage made of laminated veneer lumber is an excellent solution.

To calculate the required amount of timber, you can use a simple calculator:

Wall length

Wall width

Wall height

Beam section

150x150 mm. 180x180 mm. 200x200 mm.

Beam length

5 m. 6 m. 7 m. 8 m. 9 m. 10 m. 11 m. 12 m.

Strapping technology

Tying a pile foundation with timber is carried out in several stages:

Foundation preparation;
Preparation of building materials;
Direct installation.

Tool

If you will be tying the foundation with timber yourself, then you will need the following tool:

Hacksaw or chainsaw;
Electric planer;
Screwdriver;
Drill;
Roulette.

Foundation preparation

Preparation is carried out in two stages:

First of all, you need to make sure the foundation is horizontal. Piles that are located above the required level must either be immersed deeper or cut off. If the supports are located below the required level, then a gasket should be placed on the head.
Then you need to perform waterproofing. To do this, a roofing material gasket is placed on the ends of the supports. You can also use bitumen or roofing felt.

Preparation of building material

First, the material must be dried. Then you need to select the corner elements of the grillage and make cuts from their ends for the locking connection.

Most often, the connection is made into the floor of the tree, when the cut is made “into the floor of the tree”, to the middle of the section of the beam at a right angle, the width of the cut corresponds to the width of the beam. Also sometimes they make a “half-paw” connection, when the cut is made at an arbitrary angle. This connection is more reliable.

Advice!
The easiest way to make cuts is with an electric planer.

Laying and connecting the strapping

After the piles are leveled, waterproofing is laid on them and the material is prepared, you can begin tying.

The instructions for performing the work are as follows:

First of all, you need to outline the corners. To do this, define the point as the first external corner; it can be marked with a nail. Then I mark the remaining corners in exactly the same way, and check their straightness using a triangle.
Next, you need to make one of the corners of the future object and lay all the prepared beams. It is necessary to lay jute tape between the joints. On straight sections of the grillage, it is best to connect the elements with a half-tree or “half-foot” head stop.
When all the elements are laid, it is necessary to once again check the straightness of the corners and the horizontality of the entire resulting structure.

Advice!
The beams can also be connected to each other using metal corners and brackets.

After the strapping beam is laid on the screw piles, it must be secured. Most often, the grillage is attached to the supports using bolts. To do this, holes must be made in advance on the pile heads, and after installation, holes must also be drilled in the beams; the beams must thus be attached to each pillar.

It’s even easier to use self-tapping screws instead of bolts, in which case you won’t have to make holes in the beams. After attaching the structure, cuts are made in the grillage for logs and partition beams.

Note!
After installing the trim, it is also necessary to lay a waterproofing layer on it, and treat open areas with mastic.

In some cases, the lining of a house made of timber is not done, since its role is played by the crown of the log house itself, installed on the foundation. This option is only possible if the floor joists are cut several crowns higher.

We looked at how to frame a house from timber with one crown. Quite popular is the double harness, which we will discuss below.

Double strapping made of timber is a more reliable design than the one described above.

It has the following advantages:

The house turns out to be warmer.
In double strapping, there are no cuts for beams and joists, so it is more durable than regular strapping.
With double strapping, it is easier to remove and replace the logs during repairs, since they do not cut into the base.

When making such a design, the first crown is made of material with a cross-section of 200x200 mm. It is installed using the technology described above. In this case, it is also necessary to make cuts under the beams for the partitions.

When the first crown is completed, the second one is installed. Typically, for the second crown, beams with a cross-section of 150 x 100 mm are used, and they are installed end-to-end (the cross-section should not be square). All joints of the first row must be covered, while the corners are also connected - in a straight cut.

The partition beam is installed with its end in the middle of the beam of the first row so that there is a protrusion on both sides. Floor joists are laid perpendicular to the partition beam every 70-80 cm. They can be secured to the protruding beam using nails.

Advice!
The geometry of the harness is checked by measuring the diagonals.

This completes the work. You can learn more about double foundation piping from the video in this article.

Possible difficulties

When making a grillage you may have to face some difficulties.

The piles are not screwed level. If it is not possible to bury the pile deeper, then you can not cut the pipe, but make a recess in the beam.
The foundation turned out to be not square. In this case, the corners are leveled with a grillage.
A crack appeared on the beam. In this case, the beam should be replaced.

Conclusion

Strapping is an extremely important stage of construction, since the strength and durability of the entire house depends on it. Therefore, it should be performed especially carefully, without deviating from the technology described above.

The harness (grillage) is an important structural element of any pile foundation. The classification of grillages is carried out according to three factors: type of construction, level of placement and material of manufacture.

This page provides information about the technology for arranging different types of strapping. You will learn how to make a grillage from timber, channel and reinforced concrete with your own hands, and watch a video that reveals in detail the essence of the technology.

The timber grillage has a limited safety factor, which does not allow it to be used for the construction of heavy brick buildings, however, when constructing light wooden 1-2-storey houses from utility rooms - bathhouses, garages, verandas, in terms of economy and speed of installation, this is the preferred piping option.

Rice. 1.3

The typical size of timber for strapping is 15x15 and 20x20 cm. It is recommended to use coniferous wood, due to its greater durability compared to deciduous wood.

Important: only timber that has undergone chamber drying can be used for strapping, since the material having natural moisture will shrink, which can cause deformation of the walls of the house.

Before installation, the timber must be treated with an antiseptic agent that prevents wood from rotting, and covered with coating bitumen insulation, which will protect the material from moisture.

Technology for tying screw piles with timber:

After installation, the supports are leveled to the zero level by trimming with a grinder;
The heads are welded to the pile shafts. The welded joint is coated with an anti-corrosion primer;
The surface of the head plate is covered with waterproofing material (roofing felt, glass insulation or glassine);
The beam is adjusted in size according to the length of the walls of the house (one continuous beam goes to the side of the building) and groove joints are cut out with a grinder at the edges connecting at the corners of the house and at the intersections of the walls;

Rice. 1.4

The timber is installed on top of the pile heads, and final adjustment to size is performed. The joints between the grillage elements are sealed with jute;
With the help of “capercaillie” - wood bolts with hexagonal caps, the timber is secured to the pile heads (the plates have special holes for mounting the bolt).

Strapping with a steel grillage (I-beam, channel)

The strength and safety margin of metal framing exceeds the similar parameters of a timber grillage, which makes it possible to use it not only for the construction of frame houses, but also one-story structures made of foam concrete blocks.

Based on the material used, steel grillage is classified into two types:

I-beam;
From channel.

Rice. 1.5

Important: the choice of material must be made based on the mass of the building - a channel, due to its lower cost, is preferable when constructing light houses, while an I-beam has better resistance to compressive loads and greater rigidity, which makes it the optimal choice for heavy buildings.

I-beam tying is performed using a beam 20 cm high;
Channel - section 30 or 40 mm.

Tying with a steel grillage is practiced exclusively when arranging screw foundations. Installation of the grillage does not require installation of caps on the piles; the material is welded directly to the support shaft.

Rice. 1.6

Technology for tying screw piles with a channel grillage:

Upon completion of installation of the foundation, the pillars are aligned to the zero level;
The dimensions of the grillage parts are measured, the channel is marked and cut into sections of the required length;
Rolled metal is treated with 1-2 layers of anti-corrosion primer;
The channel is installed on piles and cut with a grinder at the joints at an angle of 900;
The grillage is fixed to the piles by welding. Upon completion of fastening, the welds are coated with a primer.

Tying with reinforced concrete grillage

Tape grillage made of reinforced concrete is used for tying bored and driven piles. It is suitable for the construction of heavy brick and foam concrete buildings with a height of 1-3 floors. In terms of arrangement, this is the most labor-intensive option for piping, but its cost is lower than that of an I-beam grillage.

Important: a reinforced concrete grillage is subject to mandatory reinforcement, which is performed by a spatial reinforcement frame consisting of two longitudinal reinforcement belts connected by transverse and vertical jumpers. The step between the jumpers is 20-30 cm. These can be rectangular welded sections of reinforcement or clamps bent into the appropriate shape.

Rice. 1.7: Scheme of reinforced concrete grillage

To assemble the frame, corrugated rods with a diameter of 12 to 18 mm are used. The body of the grillage is created from concrete grade M300-M400 with granite crushed stone filler.

Technology of tying with reinforced concrete grillage:

The shafts of concrete piles are leveled to the zero level using a grinder with a diamond wheel, a hammer or a special hydraulic hammer - a pile cutter. Only the concrete of the piles is destroyed, while the protrusions are left untouched;
A sand bedding is placed around the perimeter of the piles (to the level of the trunks), on top of which the lower wall of the formwork is laid. Next, the side walls are installed, after which the structure is strengthened with stops and jumpers that tighten the walls along the upper contour;
The formwork is covered with waterproofing from the inside;

Rice. 1.8

The frame is being assembled - the reinforcement is joined by welding or wire. The finished frame on special mushroom stands is installed inside the formwork and welded to the rods protruding from the piles;
The grillage is concreted; after pouring, the concrete is compacted by vibration or bayoneting with reinforcing bars.

Rice. 1.9

The grillage needs 25-30 days to reach its design strength, after which you can begin raising the walls of the house.

Features of tying

When tying piles, it is necessary to correctly select the level of its placement, according to which reinforced concrete grillages are classified into:

Hanging;
Ground;
In-depth.

Rice. 2.0

In conditions of stable soil, the easiest method of tying will be a ground grillage, which is located on the soil surface. Piles with a ground grillage are classified as a pile-strip foundation - this is a reliable foundation with a high load-bearing capacity, which is achieved by increasing the supporting area of the foundation with a tape in contact with the ground.

However, in soil prone to heaving, this tying option is not applicable due to the risk of the grillage being torn off from the pile shafts by buoyant loads. Here it is necessary to equip a hanging grillage raised above the ground to a height of 20-40 cm.

An in-depth grillage is a structure that is placed in the soil. Under the support base of the grillage, the soil is replaced with a non-heaving sand and gravel cushion. This grillage is used in the construction of heavy multi-story buildings, for which the safety margin of the hanging frame is insufficient.