With a bar of what section to tie a columnar foundation. Tying screw piles with wooden beams: important points. Removal of load-bearing walls outside the pile foundation

Developers quite often resort to using a pile-screw foundation. He received the greatest distribution in the construction of houses from timber or light frame buildings. In favor of this type of foundation speaks his low price and speed of installation. In some situations, a screw foundation is the only solution due to the special characteristics of the soil of complex terrain.

This type of foundation has a more complex structure. Its creation requires more time from builders. The width and height of the formwork are selected on the basis of the design calculations, which take into account parameters such as mass roofing And truss system, as well as height, width and material bearing walls.

Reinforced concrete binding is carried out in several stages:

Installation of wooden formwork along the perimeter of the external walls of the internal load-bearing partitions. The strength of its bottom must be such as to withstand the weight of the poured concrete. During the installation of the formwork, the upper parts of the supporting pillars are passed inside its box. In this case, the box will not be mounted on the heads. However, this approach requires the creation of temporary supports that will need to be dismantled after the mortar has solidified. For the arrangement of the formwork, a board or plywood with a thickness of 15-20 mm is used.
Covering the formwork box with waterproofing material. For these purposes, inexpensive roofing felt or plastic film is most often used. Waterproofing is attached to the edge of the formwork in several places. It is done so that during the process of pouring the concrete solution, the film remains in place, and does not slide under the influence of the weight of concrete to the bottom of the box. Adjacent waterproofing canvases are overlapped by 20-25 cm. Also, formwork waterproofing helps concrete gain strength and does not allow it to lose water.
Reinforcement of the future grillage. First of all, this process is carried out in relation to piles. Reinforcing bars are inserted inside the supports. They must first be connected to frame structure special jumpers. After installing the armature, the cavity of the supports is filled with concrete.
Reinforcement of the remaining grillage structure. This is done only after the concrete in the piles has hardened. A grillage frame is attached to the parts of the rods protruding from the supports.

Creation of a reinforced concrete hinged grillage

If the depth of immersion of piles into the ground exceeds 2.5 m, then sand must first be poured into them and carefully compacted. To make the base for the reinforcement rigid, crushed stone of a not very large fraction (no more than 20 mm) is also poured there. Only after these procedures have been completed, a tied or welded structure is inserted inside the support, consisting of several reinforcing bars 120-150 cm long.
In certain situations, welding of reinforcing bars to the outer surface of the pile is allowed. This is done in cases where the supports rise above the ground to a height of up to 35 cm. However, internal reinforcement is always a better option.
After the installation of the reinforcing structure is completed, the opposite walls of the box should be fastened together using jumpers. This is done to give it rigidity.
To fill the formwork, concrete of at least grade 300 is used. To remove air cavities and obtain maximum mortar density, it is necessary to vibrate it. After that, the surface must be leveled.
A prerequisite for a high-quality grillage is that all planes must be filled with concrete within a few hours. Otherwise, it will not be possible to achieve the required solidity of the structure. This should be considered before ordering ready-made concrete or in the case of its self-preparation.
After pouring, the grillage should stand until the concrete gains strength and completely solidifies. It is worth stripping after 10-14 days. It is not recommended to proceed to subsequent work related to the manufactured belt earlier than 30 days later. At low temperatures air, this period will be extended.
Gently cover the finished reinforced concrete grillage with an insulating layer and only after that proceed with the following procedures. This is done by hot or cold laying strips of roofing material on the horizontal planes of the grillage.

After completing all these operations, you can begin to build walls.

Air in reinforced concrete grillage

It is also worth mentioning another very important nuance. Particular attention should be paid to the ventilation of the foundation. If the concrete piping is at a height of 30-40 cm from the ground, then it is not necessary to make ventilation holes in it. The air will circulate thanks to the vents in the intake, which is a structure that forms the basement of the building. If the grillage is installed near the ground or on its surface, the above-mentioned holes should be provided in advance. This is done at the stage of formwork installation. In the places provided for by the project, cut pieces of plastic sewer pipes. Thus, when pouring the solution in the grillage, through holes. The total cross-sectional area of such products should be about 0.25% of the area of \u200b\u200bthe base.

Even with such a wide variety of technologies and materials that make it possible to equip pile foundation grillages, wood has not yet lost its popularity. This is due to ease of processing, low price and relatively low weight. Also, the advantages of wood include the possibility self installation strapping without involving additional forces.

strapping screw piles timber is made using softwood lumber, such as spruce, pine or larch.

Installation of a bar is carried out on heads. The presence of a waterproofing “misfire” of wood from metal is a prerequisite. To do this, it fits on the heads waterproofing material, for example, roofing material.

Before installing the wooden trim, it is necessary to treat the wooden elements with an antiseptic composition. In this case, preference should be given to a composition that has a maximum validity period, since the foundation has been in operation for several decades. You can continue to work only after the complete absorption of the protective antiseptic and the complete drying of the timber.

It is best to use a bar that has undergone an atmospheric drying procedure to a “carpentry” moisture content, which is equal to 12% . Such a beam is less prone to deformation during operation.

In any case, it is allowed to change the dimensions of the lumber. In this regard, regardless of the connection method and type of material, it is not necessary to immediately mark and cut it. Experienced craftsmen advise to pre-place the material on the heads and mark and saw in this position. The ends of the beams formed after cutting must also be treated with an antiseptic before installation.

Most often, a bar measuring 200x150 mm is used for grillage. If it is planned to build a large house with two floors on the foundation, then it is better to choose a beam measuring 200x200 mm.

A bar with a section of 200x150 mm is mounted on the heads with a side of 150 mm. Thus, the height of the strapping beam will be 200 mm.

The process of tying a pile foundation with a bar

Suppose that, according to the project, the house being built will have a large area, and the pile supports are 70-75 cm above ground level.

Therefore, after screwing in the piles, a lower harness will be required. For this, profile pipes will be used. To fix the lower trim, a welding method is used.

The heads are square in shape due to its convenience for installing "packages" of boards or timber. The top plate, which acts as the "sole" of this element, has dimensions of 250x250 mm or 200x200 mm.

On the "sole" you need to drill several holes (3-4). They are needed for fastening the strapping beams and the head. As a fixing element, a plumbing screw 120 mm long and 10 mm in diameter is usually used.

Next stage- installation of waterproofing roll material on the heads. For this, a roofing material or one of modern materials, which is based on bitumen.

The cut pieces of waterproofing should be slightly larger than the cap area by about 20mm to each side.

The presence of waterproofing linings allows you to protect the wood from the penetration of moisture into it. The main problem is that the thermal conductivity and heat capacity of metal and wood are very different in their values. In the event of a large temperature difference in metal surface condensation accumulates. That is why the site becomes wet. And everyone knows that wood must be dry throughout its entire life. The waterproofing layer is designed to separate these materials and prevent the penetration of condensed moisture into the wood, thereby preventing its biological decomposition and premature "aging", which has a positive effect on the durability of the entire foundation.

With a cap size of 200x200 mm, a fragment of waterproofing square shape should have a size of 220x220 mm.

To prevent the waterproofing from shifting from the head, bituminous mastic is preliminarily applied to the site.

So, the place for strapping is ready. It's time to start installing the beam.

As previously mentioned, proper installation involves the expansion of the beam along the perimeter of the structure. After that, it is necessary to check the perpendicularity of the beams. This is done by measuring the diagonal of rectangular sections of the foundation. If they match, then everything is done correctly.
The installation process must begin with the beam fastening points at the intersection of the beams.
The connection of the beam is carried out "in half a tree". This method is the simplest and far from the most perfect. Experienced craftsmen resort to more reliable connecting nodes, one of which is “in the paw”.
The ends of the timber after cutting should turn out to be even and neat. Otherwise, when they are docked, it will not be possible to achieve a snug fit.
It is recommended to additionally lubricate the joints with carpentry glue.
Hex head self-tapping screws, which are used to fix the beam to the heads, are screwed in from below.
To facilitate screwing screws into a tree, you must first outline the holes. This is done by creating a hole of a smaller diameter. This should be done after the timber is laid on the heads. A socket wrench is used to tighten the screws.
The tie-in of the beam located inside the perimeter of the foundation is carried out “in half a tree”. At the joints, cuts are made and excess wood is removed. Then you need to remove part of the edge of the beam, which is supposed to be cut into the main harness. The fragment to be removed is 150 mm long and half the thickness of the beam.

a) Corner connection; b) inner join

In the groove, the embedded part of the timber should sit tightly. In this case, the jumper becomes flush with the surface of the main external trim.
For additional fastening of the connecting nodes, steel brackets 25 cm long are used, made of a rod with a diameter of 8 mm.
These fasteners are considered optional. In some cases, the length of plumbing screws may not be enough to ensure reliable fixation of beams of large thickness to each other.
The bracket is driven in at the beam connection points from above into the timber. The legs of the staples are driven into whole parts of the beam, and not those that have been weakened due to the selection of grooves "in half a tree".
Sometimes it is extremely difficult to drive a bracket to the required depth (flush with the surface of the beam) due to its large thickness. In this regard, this operation is carried out according to the following algorithm:
Lay the bracket to the place of its installation and make markings on it.
Make a cut along the marked line. Cutting width - 78 mm, depth - 10 mm.
Drill holes with a diameter of 56 mm in the places where the legs are driven in. This will prevent crack formation.
Handle drilled holes and resi antiseptic composition.
Install the brackets in the places intended for them and drive them flush with the surface of the beam.
In the joints at the crosshairs of two beams, the docking is performed "in half a tree". Self-tapping screws are screwed from below, and staples are driven in from above, forming a square.
In places where staples are driven in, the surface of the beam must remain flat. Otherwise, the protruding parts of the brackets can greatly complicate the process of building walls.
After finishing the fastening of the beams to the heads, it is necessary to check the resulting structure for horizontalness.
To do this, you need a building or water level. The building level is used when the sides of the foundation are not too long.
The installation of a beam can have a difference in the line from one corner of the building to another within 5 mm. The linear parameters of the structure and its horizontalness must correspond to the data presented in project documentation.
If there are errors, they will need to be taken into account in further calculations carried out for the construction of walls.

Conclusion

Thanks to technical specifications some materials, it is possible to independently mount the strapping without involving a team of professionals and using sophisticated equipment. But when building a massive structure and lack of experience from the owner of the site, it is still recommended to seek help. to specialists. When arranging the foundation, mistakes should not be made. This is not the kind of work by which one should learn to build.

The growing popularity of frame construction is explained by the fact that this method allows you to build houses in a very short time. To speed up the work even more, pile-screw foundations are used as the foundation. The fact is that in the process of their arrangement there are no wet processes. To inform the base of proper stability, you will need competent tying pile foundation.

For sustainability wooden house it is not enough to drive piles into the ground - they still need to be fastened together from above Source fucbgik.kal.ru.net

Features of the pile foundation

Pile-screw foundations are very common in low-rise construction. This is especially true for the construction of frame and timber houses, which are distinguished by their low weight.

This is explained by the following advantages of pile structures:

Possibility of use on difficult soils. This refers to weak, heaving and frozen soil. The same applies uneven areas when, due to the features of the relief, this type of foundation turns out to be the only possible solution.

Long service life. Compliance with the technology of arrangement, application quality materials and proper operation ensures a long service life of the pile foundation (at least 100 years).

Cheapness. Other types of foundation are much more expensive.

Simple and fast construction. For immersion of screw supports, a special technique is usually used, which allows this procedure to be carried out in a few hours. There is also an option with manual screwing, which can be handled by 3-4 people.

Screwing screw piles with the help of special devices will save a lot of time. Source clubwell.ru

When laying the foundation of screw piles, labor-intensive excavation. The main thing is to correctly calculate the screwing depth and the distance between the supports.

The determining factors in the calculations are the massiveness of the future building and the characteristics of the soil - its composition, the depth of groundwater and the degree of freezing.

When considering the possibility of using a pile foundation, it is important to take into account the fact that there is no solid support surface in the structure. This causes certain difficulties when using materials for small format walls. The existing problem is solved by tying screw piles, for which several technologies can be used. The correctness of this procedure directly affects the strength qualities of the finished building.

The reliability of the entire structure will depend on the strength of the pile foundation. Source kursremonta.ru

Why strapping is needed

The binding function is performed by the upper element of the base - the grillage, for the arrangement of which you can use several methods (the choice depends on what the house is built from). The grillage cannot be considered an obligatory structural element of the pile foundation. Despite this, it is recommended to use it in every case, which guarantees the reliability and stability of the structure.

Rostverk performs the following functions:

Evenly distributes the load on the piles. This is especially true in situations where, due to the characteristics of the soil, the supports have different immersion depths. This state of affairs can cause distortions and shrinkage of the building. Thanks to the grillage, the risk of such situations is minimized.

Creates general design from individual piles. After that, the supports cease to "live their own lives", forming a reliable frame for the house. As a result, the spatial rigidity of the structure and its service life increase by 2 times.

Ties the foundation around the perimeter. Shallow and recessed grillage contributes to an increase in the area of \u200b\u200bsupport to the ground and creates protection for the underground zone from influences from the street.

Scheme of a pile foundation with a shallow grillage Source pobudova.in.ua

On our website you can find contacts of construction companies that offer foundation repair services. You can directly communicate with representatives by visiting the exhibition of houses "Low-Rise Country".

The foundation piping is classified according to the type of material used:

Wooden from a bar. Used in the construction of wooden frame houses and timber buildings. The arrangement procedure is cheap, and can be implemented alone, or with one assistant.

Boardwalk. In this way, small wooden and frame buildings are equipped. For the construction of the grillage, the so-called. composite beam from several wooden boards.

Metal. A channel grillage is able to provide stability for a two- or three-story wooden house.

Reinforced concrete. This design demonstrates the greatest reliability and durability, and can be used in capital construction. In the process of arrangement, the concrete solution is poured into a pre-assembled formwork equipped with a reinforcing mesh.

Tying a pile foundation with a bar is the most popular in the construction country houses and cottages. This is especially true for regions with a harsh climate and permafrost.

Wooden strapping is used only for frame buildings and timber houses Source postroifundament.ru

Material selection

The pile foundation grillage is most often equipped from a bar 200 × 150 mm. If the house being built has an impressive size, then it is better to strap it with a bar of 200 × 200 mm. Using material 200 × 150 mm, it must be laid on the heads with a narrow part. Thus, the strapping beam will have a height of 200 mm.

Head base preparation

For the convenience of subsequent construction procedures, the tops of the piles are equipped with special square plates (heads) measuring 250x250 cm.

They need to be prepared accordingly:

Drill several holes (usually 3-4 pieces). They facilitate the procedure for attaching wooden strapping with plumbing screws. Screw size - 10x120 mm.

To fasten the strapping on the heads, holes are made for self-tapping screws. Source svaybur.ru

Carry out waterproofing of the heads with roofing felt or innovative bituminous material. When cutting pieces, a margin of 20 mm per side is made for each head: this facilitates fixation.

Thanks to waterproofing gaskets, protection for wooden piping elements from the damaging effects of moisture is provided. Its source is the condensate that forms on a cold metal surface during temperature fluctuations. Every possible effort should be made to keep the wood dry at all times.

The waterproofing layer between the sole of the head and the beam prevents the penetration of condensed moisture onto the strapping. This significantly increases its service life and prevents rotting. To prevent shifting of waterproofing sheets, the sole of the head is smeared with bituminous mastic.

Waterproofing between the head and the timber is required, otherwise, due to moisture, the harness can quickly “wear out” Source stroy-dom-pravilno.ru

Fastening bars

To facilitate installation, apply a preliminary layout of the beam around the perimeter of the entire structure. This makes it possible to comply with all design parameters for tying the foundation with a bar. The laid beams must have a right angle of docking with each other. To check the perpendicularity, measure the diagonals of the corner sections - they must be identical.

The order of installation of the beam:

The mounting nodes are selected as the starting point for installation in areas where the beams intersect with each other.

Docking timber is usually done "half-body". More rarely, a more reliable “paw” connection can be used. To ensure the tightness of the timber, its ends must be cut off as evenly as possible. The connecting sections are additionally coated with wood glue.

The fastening of the beam to the sole of the heads is carried out with hexagonal screws, which makes it possible to screw them in from below. The screwing procedure is facilitated by pre-drilling small diameter holes at the attachment points. A socket wrench is used to tighten the screws.

The beam inside the perimeter of the grillage is also cut into "half-body". Before this, the timber on the connecting sections is equipped with grooves.

Joining grillage beams at the corners of the foundation perimeter Source stroyfora.ru

After that, it is cut into a part of the end, which is immersed inside the main harness. It is necessary to ensure that the embedded fragment enters the equipped seat as tightly as possible.

Additional mount

For reliability, the elements of the connecting nodes are additionally fastened with steel brackets made of a metal bar with a diameter of 8 mm. This must be done in the case when the length of the self-tapping screws is not enough to firmly fasten thick beams. The place of installation of the brackets is chosen the upper part of the beam, opposite the connecting nodes. The sharp ends of the fastening must be driven into solid sections of the beam that are not equipped with “half-tree” samples.

It is not always easy to completely drive an 8 mm staple into the wood, so this procedure is implemented as follows:

Marking is applied. To do this, it is enough to attach the fastener to the surface of the beam and circle it with a marker.

A groove is cut along the marking line with a depth of 10 and a width of 8 mm.

The points on the surface where the legs will be immersed are equipped with holes with a diameter of 5-6 mm. This will protect the beam from cracking during the clogging of the bracket.

Holes and grooves must be treated with antiseptic impregnation.

Clogged staples should not rise above the surface of the beam Source zen.yandex.ru

Staples are being hammered. They must be immersed flush into the surface of the beam.

At the intersections of two beams, a half-tree joint is used. Self-tapping screws are screwed from below. Staples hammered from above (4 pcs.) Should form a square shape.

Installed brackets should not protrude above the common surface, otherwise it will create difficulties for subsequent construction work.

Video description

About the features of tying a pile foundation in detail in the following video:

Checking the horizontality of the structure

When the tying of the screw piles with a bar is completed, they check finished construction to horizontal. To do this, use a water or building level. Permissible diagonal difference between opposite corners - no more than 5 mm. All parameters of the finished strapping must exactly comply with the instructions in the project documentation. The observed errors must be taken into account during the construction of wall structures.

Checking the horizontal position is a mandatory step, bypassing it you can get a lot of problems with the house in the future Source vse-pro-stroyku.sqicolombia.net

Outcome

The pile foundation allows you not to depend on the characteristics of the soil and the climatic conditions of the region. When it comes to building a lung frame house, tying piles is usually performed using a beam.

The construction of a frame house is a responsible process, each stage of which is of great importance for obtaining positive result generally. Failure to comply with certain building rules, non-compliance with technology and sequence during installation can lead to big problems and significant financial costs in the subsequent operation of the entire structure.

The correct installation sequence of the strapping largely depends on the type of foundation. Consider the process of performing the lower piping using the example of a pile (metal, reinforced concrete piles) foundation. Due to the speed of construction, long service life and affordable price, this type of foundation is widely used.

Types of strapping, materials and design solutions

The lower trim can be structurally made of timber, cohesive boards or logs. Since the wood from which the lower trim is made will be subjected to significant loads during operation, it is worth choosing high-quality material to create it.

It is better to give preference to softwood lumber (pine, spruce, fir, larch), since the presence of natural resinous substances in wood creates an additional barrier to the processes of decay, mold, fungus and reduces its hygroscopicity. Also, the availability and relatively low price of these types of wood are an additional criterion for the purchase.

Fig. 1 Coniferous trees

Let's take a closer look at the types of strapping:

In the case of using timber, unplaned lumber of various sections (150x150mm, 200x150mm, 200x200mm) is used. This lumber has strict dimensions, it is easier to install, and a large section provides a load-resistant support. At the same time, it is prone to cracking and warping.
In plank strapping, such defects are largely prevented. A cohesive board can withstand loads over time and provides good flatness, the shrinkage process is compensated by the multi-layer construction. The board is also suitable for various sections (150x50mm, 200x50mm).
The use of a log as a material for strapping reduces costs, the log can withstand significant loads, and a large mass contributes to an increase in the stability and reliability of the entire structure. The disadvantages are the wrong geometry, the complexity of installation and fastening on the foundation. This type binding is practically not used.

Proper installation - reliable design

The bottom trim is a necessary element to create a reliable connection between the foundation, walls and floor joists. It is also necessary for the construction of a flat platform, the adoption and uniform distribution of the entire load from the structures of the house.

During installation, certain rules must be followed:

preliminarily, waterproofing is laid on the foundation elements;
timber (board) must be calibrated with great accuracy and matched to size;
treatment with antiseptics is mandatory to exclude the process of decay of the material;
the strapping must have a strictly horizontal plane to avoid uneven loading;

Step-by-step strapping device from a bar (150x150mm).

1) The strapping beam is sawn to size in accordance with the foundation strapping plan. Then each beam is trimmed into its own knot.

Fig. 2 Connection nodes of the strapping beam

3) All nodes are fastened together (nails 150-200mm).

4) And, finally, the strapping is fastened to the foundation (to the pile head). Anchor bolts or threaded rods are used as fasteners.

Fig. 3 Strapping from a bar on a pile foundation

Step-by-step strapping device from cohesive boards (50x150mm).

1) The assembly of the lower trim from the boards begins with the perimeter (extreme boards). The boards are sawn in accordance with the strapping plan, the ends are interconnected with nails.

2) After laying the edge boards on the foundation, the diagonal dimensions are checked.

4) For greater strength, the boards are pulled together with studs.

Fig. 4 The main knots of the strapping connection from the board

5) The strapping is fastened to the foundation (to the pile head). Anchor bolts or threaded rods are used as fasteners.

Fig. 5 Strapping from a board on a pile foundation

Floor logs: materials, features of work

For the organization and installation of the subfloor, finishing coating and insulation, floor logs are used. They represent longitudinal beams specific size, made from various materials. The most applicable are logs made of wood. For wooden lag when you can use coniferous wood (pine, spruce, fir, larch). Log wood should not have visible defects, delaminations, transverse cracks and a large number of knots.

The dimensions of the beam (50x150mm, 100x150mm, 50x200mm, etc.) and the step between them depend on the span of the lower trim, the load and the size of the insulation.

If you are planning to build a house on your own, then calculators for calculating beams will help you, where you can choose optimal dimensions, step and beam material.

A prerequisite for installing the log system is their location in the same plane, which is checked by a control rail. It is also desirable to treat with an antiseptic to prevent the process of decay of the material.

There are several options for attaching the lag to the bottom harness:

1) With support on a bar. A bar is attached to the harness, located in the lower part, on which the end of the log rests. With this method, additional fastening of the log to the harness is necessary, since the bar is only a support, it does not create a ligament with the bar.

2) Using metal plates, corners. In this case, there is a reliable connection of the end of the log with the strapping beam, but there is no support from below, the log “hangs” on the metal part.

3) Installation on top of the harness with direct support on it. This method allows you to securely connect the log with the strapping, create a high-quality support and connection. In this case, the installation of wall frame racks will require an additional bundle on top of the log.

In practice, the third method is most often used, or the first two are combined - they use a support bar and metal connecting elements at the same time. This maximizes the connection between the lag and the strapping, allows you to more accurately maintain the plane of the subfloor and simplifies the process of installing the lag.

Phased installation of floor joists (50x200mm).

1) Based on the floor plan, installation of facade or end boards is carried out (they serve to fix the log in a vertical position and mark the position of the log). The boards are installed on edge and aligned with the outer edge of the strapping.

2) Fastening of boards is carried out at an angle with nails (100-120mm) or with the help of corners and self-tapping screws.

Fig. 6 Installing the front board on the strapping

3) After marking, the installation of the logs themselves is carried out, the step of which is calculated depending on the load and the size of the spans.

Fig. 7 Mounting the floor joists on the harness

Fig. 8 The distance between the lags for easy installation of insulation

4) The lag is fastened with nails.

5) After installing the log, the installation of spacers (lintels) or transverse stiffeners is carried out. Installed to fix vertical position log and distribute the point load on the floor log between two adjacent ones.

Fig. 9 Arrangement of jumpers (stiffeners)

6) Arrangement of jumpers in a checkerboard pattern is possible for ease of installation. The main thing is that they are tightly knocked down.

Fig. 10 More convenient jumper arrangement

7) Jumpers are also installed that support outer wall(a wall that is parallel to the next joist) and lintels supporting non-load-bearing partitions (in the future, partitions will be installed on them).

8) Jumpers are also fastened with nails.

Compliance with these simple rules guarantees correct assembly basement, which will serve as a reliable bond for the floor, walls and foundation and provide long service all elements of the frame house.

Fig. 11 Finished basement

The screw pile foundation remains one of the most popular solutions for individual construction due to its affordability, simplicity and stability even on “floating” soils. However, in order for your home to be even more comfortable and not require repairs for as long as possible, it is necessary to make its foundation even stronger and more durable. For this, operations such as tying and closing screw piles are performed.

What is the difference between tying a pile foundation and closing it?

Inexperienced builders often confuse tying screw piles with closing the foundation. Although these two stages of the process of building the foundation of a house are connected in some way, they serve slightly different purposes.

strapping involves combining the heads of screw piles already installed in the ground into a single structure around the entire perimeter of the foundation and along the contour where they will be built internal walls buildings.

The lack of strapping, which is done using timber, boards, channel bars and other materials, will lead to an uneven load on each pile. The consequence of this will be the rapid destruction of the foundation, which will simply “float”.

Closing screw piles gives the building a more aesthetic appearance and minimizes heat loss. After all, since the foundation is not monolithic and there is open space under the house, the floor in such a building is unlikely to be warm enough.

For closing use a variety of modern materials.

Strapping options

Tying piles with timber

Owners of relatively light buildings - wooden or frame-panel - should give preference to this particular type of strapping. A grillage made of timber cannot be called very durable, but for such construction it is the most suitable and affordable option.

Foundation tied with timber.

Often, a bar made from coniferous wood is used for strapping, since its cost is several times less than similar products made from hardwood, and the differences in performance are minimal.

Before installing the grillage, special antiseptic compounds must be applied to the timber to prevent the destruction of wood under the influence of atmospheric factors, and covered with a bituminous waterproofing layer. The latter gives the timber water-repellent properties.

When tying a pile-screw foundation with a bar, do the following:

The pile head is mounted after the pile is leveled (cut) and after concrete is poured inside it (if necessary).

Carefully align the installed piles so that the pillars are exactly at the same level.
Heads are mounted on piles.
Perform waterproofing material.
On the beam, which falls at the joints of the corners of the house, grooves are cut right size for subsequent connection wooden parts between themselves.
The timber is laid out on the pile heads along the perimeter along the entire contour of the foundation in such a way that the joints of the separate parts of the grillage are fastened together on the heads. At the same time, the joints are laid with a bundle for better sealing.
Align the grillage and carefully check the angle: it should not deviate from 90 degrees.
The beam is fixed on the pile heads with self-tapping screws.

Tying piles with a board

When installing a pile foundation, the strapping with a board has a number of indisputable advantages compared to a beam:

When carrying out work cracks may appear in a beam with a too large cross section or it is significantly deformed.
For making beams a beam longer than 6 m is not suitable because of the serious problems that may arise with this.
Beams from a bar are quite heavy, so for their installation will require a whole team of workers. At the same time, a beam of boards is made right next to the foundation, which is much easier.
Beams from boards do not require additional drying and are distinguished by increased strength in comparison with analogues from a bar.

The binding of screw piles using boards is performed according to the following algorithm:

Between the pile heads and the actual strapping, a waterproofing moisture-proof layer is necessarily made, often from high quality roofing material.

The photo clearly shows the waterproofing of the head from the strapping, as well as the bed.

There is another way to tie a board. The boards are glued together and additionally fastened with screws and nails. With a small thickness of the boards, you can lay them with plywood for greater strength. During installation, it is important to separate the joints of the boards into different piles and use the proven “half-tree” method.

Binding of piles with a channel (I-beam) or corrugated pipe

Metal grillages make it possible to use a pile-screw foundation in the construction of not only wooden buildings, but also buildings made of cinder blocks, foam concrete and gas silicate on one floor.

Sometimes, instead of a channel, an I-beam is used, which is highly resistant to compressive loads and provides greater structural rigidity. I-beams with a section of 20 are often used. In the case of a channel for load-bearing walls, metal beams with a section of about 30 mm are taken, for the rest - with a section of about 20 mm.

The foundation is tied with a channel or an I-beam as follows:

Pile columns are installed at the same height and the metal trim elements are treated with an anti-corrosion agent.
Metal beams are placed on piles so that they are connected in the middle of the pile columns. The channel is cut at a right angle at the corner joints of the grillage elements.
The beams are welded to each other and to the pile heads.

On this photo the foundation is tied with a channel, and profile pipe(bottom).

The piping of a pile foundation with a corrugated pipe is carried out in almost the same way, however, the resistance of such a material to significant mechanical loads can be much less. Of the advantages of the pipe, we note low cost and low weight.

Piling of piles using reinforced concrete grillage

Reinforced concrete binding of a monolithic type is almost a third cheaper than a metal one, however, it has a number of disadvantages, the main ones being the laboriousness of the installation and the impossibility of continuing construction until the grillage has completely hardened. This usually takes at least a month.

Tying piles using reinforced concrete grillage: the final version.

When tying piles with a reinforced concrete grillage, it is necessary to proceed as follows:

Piles of piles put on one level.
Formwork is made from planed boards for further pouring with concrete, which is covered with oilcloth from the inside to prevent leaks.

Finished wooden formwork on concrete piles.

What is the pile foundation covered with?

A closed pile-screw foundation is a reliable protection against rodents and other animals that can settle in the empty space between the piles. Also, the sheathing and finishing of such a base will prevent heat loss in the home and help create a good microclimate there without excessive humidity.

The most popular ways to close a pile-screw foundation:

creation of a hinged plinth;
creation of a shallow tape-type plinth.

For a hinged base, thin and not too powerful composite and polymer materials as well as wood. At the same time, the load on the screw piles is minimal, and the simplicity and speed of installation, combined with low cost, often captivates.

Hinged plinth covering the foundation with a professional pipe piping.

Any type of base finish on piles requires the presence of two ventilation holes on opposite walls of the house. This will prevent moisture from accumulating on the piles and grillage, which will not corrode or rot (in the case of wood).

However, the pile foundation will last longer with the installation of a shallow-seated tape base, which will be the best protection for the pile frame, guaranteeing its durability.

A variant of the construction of a shallow basement to protect the pile foundation.

Thermal and waterproofing when closing the plinth

All types of plinth finishes involve the arrangement of a heat and waterproofing layer, which is covered with asbestos-cement slabs, decorative thermal panels mounted on a crate of boards or a slate slab, or bricks. All of these materials have their pros and cons:

Asbestos-cement slabs they do not look very attractive and are characterized by increased fragility, but they are inexpensive.

Decoration of the basement with decorative bricks.

Tying and closing screw piles is a very important stage in the construction of a house, which determines how soon it will need a major overhaul.

Tying and closing the pile-screw foundation: how to make the foundation of the house durable?

Closing and tying a pile-screw foundation are slightly different operations that make the foundation of the house more reliable and stable. For this, many modern materials are used.

In individual construction, the owner seeks to save every ruble, and a columnar, pile or combined foundation is 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 moments in the construction of columnar foundations, and this is the piping of the pile foundation, that is, a kind of grillage, if we are talking about concrete, and a powerful lower belt, if the piping is done wooden beam.

What is the need for tying the foundation

The foundation itself is much easier and faster to perform than to do the subsequent strapping with a bar with your own hands, metal or concrete. Nevertheless, it must be built, and why do this, we will consider in more detail. To comply with the technology, one should correctly understand the principle of operation of a pile or column foundation. Typically, such foundations are erected for objects with a low total weight, since the load capacity of any screw pile or column of any material is enough to support the weight of the structure. In addition, financially tying screw piles with timber is much more profitable than building a strip or slab foundation, and it takes several times less time to build. The photo below shows a double strapping with a bar:

The pile foundation includes several piles - depending on the total area of \u200b\u200bthe private building object they can be from several units to several tens. Piles can serve as pillars made of steel or reinforced concrete pipes, immersed in the ground to the estimated 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 on the ground, and so that the house does not warp, the piles are tied with a structure made of a suitable material. Such a strapping of a house from a bar reduces the pressure on 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 "strapping 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 strapping can be called a grillage, as it serves to enhance the strength and extend the life of the building.

Varieties and stages of strapping

The binding of the pile foundation with a bar is done sequentially:

Prepare the foundation - level it and waterproof;
Prepare the building material grillage;
Mount the strapping belt.

The screw piles are tied with timber or other building materials if the piles rise above the ground ≥ 0.5 m. 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. Strong binding of the pile foundation with a beam is made with a section of ≥ 150 mm, square in shape. Hardware for connections in the structure - steel studs M14-M16 or clamps made of soft thick wire. The beam must first be waterproofed, as well as impregnated with flame retardant and antiseptic compounds. Metal parts are protected with anti-corrosion agents;

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

3. Reinforced concrete tying of piles is made prefabricated or cast. Structurally, such a strapping resembles a strip foundation laid on piles or poles. It is done for brick or block houses, but with appropriate calculations it can also be used for wooden buildings. In prefabricated piping, beams are used, which are laid on piles and connected to each other. For the construction of a solid grillage, a formwork is made into which a reinforcing frame is installed and a concrete solution is poured. The formwork is made removable ( sheet materials, boards, etc.) or non-removable (extruded polystyrene foam);

How to fasten the harness

Before proceeding with 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 framing of the foundation with a beam 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 outer binding of the pile base is double.

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

For threaded hardware - bolts, screws, studs;
for welding;
For clamps or staples.

Tape base

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

Installing a wooden strapping on a strip base:

The surface of the foundation must be strictly horizontal and even. The difference in the surface of the tape in height should be + / - 1 cm, so the irregularities are filled with a thin screed, and smaller differences are adjusted with wooden linings;
The surface of the reinforced concrete tape must be waterproofed. To do this, use bitumen, roofing material or a thick plastic film. The material is laid or applied in 2-3 layers;
Holes are drilled in the beam with a diameter of 1-2 mm larger than the diameter of the anchors poured into the body of the concrete tape. A rubber gasket and a wide steel washer are put on each anchor, which protects the tree from deformation when the thread is tightened;
The strapping beam is laid on the waterproofing layer so that the anchors get into the holes. With each other, the beam is connected "into a bowl" or "into a paw";
Nuts are screwed over the washers, and studs are not required at the connection points of the beam;
After installing the strapping belt, the assembly of the walls of the house begins.

pile foundation

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

The sequence of tying the pile-screw base:

First, the strapping from the timber is attached to the threaded connection to the piles. A beam of estimated length is placed between two piles, and where it contacts the metal, a roofing material is laid. It is desirable to additionally impregnate 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 timber, 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 screws or galvanized screws;

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

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

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

After connecting the beam along the perimeter of the object, it is necessary to put on a structure from a beam of a smaller 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 bar. With the help of these clamps, the fastening of the entire strapping is strengthened. In the process of assembling the main harness, these wooden clamps are fastened to adjacent piles for thread or metal corner. 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.