Do-it-yourself tying of screw piles with timber. How to make a timber frame for a pile-screw foundation. What is tying a pile foundation and why is it necessary?

The reliability of a pile-screw foundation, as well as any other building foundation, depends on compliance with technological recommendations, as well as on the correctness of its geometric parameters. Today we will look at the main points regarding the arrangement of wooden lining for a pile-screw foundation. We learn about possible errors, as well as rules that must be followed, from the experience of FORUMHOUSE users.

In this article we will consider the following questions:

What type of wooden strapping design is considered a gross violation of existing technology.
What is better to mount the piping of screw piles from - solid or stacked timber.
How to properly join beams on pile heads.
How to prepare timber for installation on piles.
In what sequence is the wooden frame installed?

Let's assume that the pile part of the foundation is already ready: the piles are screwed into the ground, the heads are welded, and the deviation of the horizontal level of the screw piles corresponds to the permissible errors. We will not take responsibility by discussing what distance should be between the piles or how deep they should be screwed into the ground. Also, we will not give advice regarding the appropriate diameter of the piles. Only professional designers can reasonably answer these questions, and you should contact them for appropriate calculations. To begin with, we want to warn you against a serious mistake, which many unprofessional developers are tempted to make.

Removal of load-bearing walls beyond the pile foundation

Sometimes private developers try to find solutions that allow them to save on the purchase of building materials and the work of screwing in additional piles. At the same time, they forget about the strength of the building structure, which can be broken very recklessly.

Here is an example of a gross violation of construction technology; the photo shows the removal of the outer wall beyond the boundaries of the pile row.

What can you recommend to people who prioritize questionable savings? The most important thing is to avoid self-indulgence, and then everything will work out for you. If building regulations provide for the installation of piles under each corner or wall of the future room, then so be it. There is no need to make any overhangs or indentations that are not supported in the form of a pile firmly screwed into the ground. This will not lead to a reduction in the cost of construction, but it will provide additional problems for the developer.

Guffych User FORUMHOUSE

If you make an overhang or indentation, then this structure will hang on the logs. In this case, you will have to make a double strapping from the inside and connect it somehow with the external overhang (so that the structure does not completely fall apart). It won’t be cheaper (due to savings on piles), since you will have to spend money on strengthening the lower floor, but this will add problems.

If you plan to add additional architectural elements to the house (a veranda or, for example, a porch), their corners should also be supported by metal piles.

Earth user User FORUMHOUSE

In general, according to the technology of constructing a pile-screw foundation, piles must be placed under all cuts, corners and load-bearing walls. This is the most important rule.

Timber or board - which is better?

Let's talk about what material is best to use to create a wooden frame. Construction regulations allow the use of solid wooden beams (150x150, 150x200, 200x200) or beams sewn from several boards (50x200). Laminated timber qualitatively replaces solid timber and even surpasses it in some characteristics. Three boards sewn together replace a beam with a section of 150x200, while four boards are similar to a beam of 200x200.

The beam, one side of which is 200 mm, is laid on the heads with the smaller side. The height of the strapping is equal to 200 mm.

Both options (both with timber and with boards) are popular and both are correct. At the same time, having studied the advantages and disadvantages of each material, many developers make their choice in favor of stitched boards.

AlexSpb User FORUMHOUSE

Why do you need to use 150*200 timber? Knock down 3 50*200 boards instead and don’t bother with this log. This topic constantly comes up on the forum.

The word “log” was not mentioned by the user by chance. Solid timber is a relatively heavy building material and, with a limited number of workers, moving it from place to place (even on a small construction site) will be very difficult. In addition, solid timber does not resist bending well (worse, in any case, than boards placed on edge), which makes its use less practical.

Boards, unlike timber, must be firmly connected to each other before installation on piles. And these are additional costs, and this, perhaps, is their main drawback.

builder User FORUMHOUSE

The boards are nailed together with nails in two rows with a pitch of 20 cm. At each head they are fastened not with one wood grouse, but with four.

As for the length of the nails: for a composite beam of three boards (50x200), nails with a length of 90 - 120 mm are sufficient. They are made on both sides in a checkerboard pattern, as user builder indicated. The distance between the nails is 20...45 cm. If the beam is made up of four boards, first 3 boards are knocked together, then the fourth is attached to them (with the same nails).

Now let's talk about the "grouse" mentioned in the quote. A “grouse” is a fastening element - a self-tapping screw, the head of which is made in the form of a hexagon (for a wrench or impact driver).

With the help of a capercaillie, the beam is attached to the head of the pile (the capercaillie is screwed in from below).

The diameter of the capercaillie for attaching the strapping beam is 8...10 mm, its length is 100...150 mm.

To prevent the beams or composite beams from splitting while screwing the wood grouse, a hole must be pre-drilled in the wood.

A small table will help you determine the diameter of the drill.

Technology for connecting and extending timber

The length of a wooden beam (both solid and composite) rarely corresponds to the distance between the pile heads. In order to adjust the beams to the dimensions of the foundation, they have to be cut or sewn together. When building timber, you must follow one important rule.

Any joints must have a support point underneath. This applies to both stacked beams and solid timber.

builder

The joints of the boards do not need to be made hanging. Join the boards at the pile heads.

By splicing timber in this way, you will increase the consumption of wood, but ensure the strength of the pile frame.

The beams on the pile heads also need to be spliced correctly. If a solid beam is spliced, then cuts are made on two adjacent beams. The upper half of the beam is sawed on one beam, and the lower half on the other. After this, both beams are connected into a lock. This connection is called a “half-tree connection.”

At first glance, everything looks extremely simple. But there is an important rule for connecting two elements of one load-bearing beam: both adjacent beams must rest on the head of the pile at the point of connection of the load-bearing beams, and not just one. First, let's give an example of an incorrect connection.

Dimc User FORUMHOUSE

The support area of the beam on the head (at the junction of two purlins) must have a length of at least 90 mm. In the figure, the beams are “cut” at the junction. One has the upper half cut off, the other has the lower half. If the beam rests on the pile head only with its “cut” part, then its working section should be taken as the cross-section of only this part. If the beam rests completely on the head (at least 90 mm in length), then everything is correct: the harness will work like a solid beam.

The purlin in this case is the supporting beam in the framework of the frame house.

This rule also applies to corner trim joints. Here are examples of correct beam connections.

Basic beam connection diagrams (top view).

In order for the beam to have a sufficient support area, the pile heads must initially have dimensions corresponding to the cross-section of the beam.

The question naturally arises: how to lay timber at the junction of several beams (for example, if three beams are joined at once on one head)? This is what the experience of our users suggests.

Dimc

Beam junctions can be arranged in two ways. In the first case (when all the beams are load-bearing), in order to provide a sufficient support area, it is necessary to increase the head. In the second (when only one beam is load-bearing), we place the load-bearing beam on the head, and the auxiliary beam can be attached to a suspension - such a part (in fastener stores it is called a “beam holder”).

The increase in the support area is carried out according to the following scheme:

With the correct placement of piles, even auxiliary beams will have several points of support, which will make the foundation structure quite strong.

If you approach the design of the harness more rationally, if, where possible, you use beams of small width, then there should be no problems with constructing the correct connections. Here is an example of tying a frame house.

Dimc

I designed the framing as follows: the purlins (main load-bearing beams) marked with green arrows are load-bearing. The outer beams consist of 3 boards 50x200, the middle one - of 4 boards 50x200. And the beams marked with yellow arrows are auxiliary (not load-bearing) and consist of 1 50x200 board. They serve to increase the overall rigidity of the structure.

Stacked load-bearing beams (beams made of boards) at the junction points must also have a sufficient support area. We present to your attention examples of correct connections of inlaid timber in various sections of the strapping.

Preparing timber for installation on piles

Preparing the harness for installation on piles involves treating the wood with antiseptic compounds, as well as cutting pieces of the required length. For antiseptic treatment, bioprotective compounds that can simultaneously perform the functions of a primer are best suited. You can find out the recommendations of developers regarding the use of certain protective compounds here.

Some developers strive to dry the wood to optimal moisture content before installing the trim. What should be the moisture content of the timber used for the construction of the frame? Experienced users of FORUMHOUSE believe that if the wood has a marketable appearance, if its humidity is not prohibitive, then it is better to use it for the construction of the frame in the form in which it was purchased. And drying boards or timber at home will do more harm than good.

Kedruchu User FORUMHOUSE

The timber must be dried in a special chamber, and not behind a barn or under a film. They build the frame immediately after purchasing the wood, and it dries inside the building structure. Everything that had time to sit before construction is then only good for firewood, alas.

This advice is for those who do not want to end up with timber twisted in all possible directions after inept drying.

Sequence of construction and fastening of the harness

First of all, the timber, impregnated with an antiseptic and cut in accordance with pre-designed markings, is laid out on the pile heads. The cuts and grooves in the wood are also made in advance.

After this, you can proceed to the most important stage - aligning the strapping along the diagonals and along the length of the beam.

Remember: errors made while screwing piles are normal. The pile heads can be shifted 1-2 cm away from the straight line, but the piping that is installed on them must have a perfectly even geometry.

If you end up with a diamond shape at the base of the house (instead of a clear rectangle or square), then you will never be able to align the walls and roof of the house. It is for this reason that you should concentrate your attention on the geometry of the harness, and not on the alignment of the heads.

The diagonals of the strapping, laid but not yet secured on the piles, must be checked and aligned several times. Only after this can the timber be secured at the corner points of the pile foundation.

Having secured the corners, you should check the geometry of the side and internal beams. To do this, use a rope stretched between the corners along each side of the harness.

The side and internal beams should be fully secured to the pile heads one at a time, checking them for displacements away from the straight line.

Leo060147 User FORUMHOUSE

Do I need to put anything between the heads and the timber while building the frame? There is no point in such waterproofing. Unlike concrete or other porous materials, metal does not have capillaries. Therefore, capillary moisture from its surface cannot get onto the timber or any other material.

For those who want to learn from people with experience, we recommend visiting the corresponding topic, open for discussion on our portal. This article will help you save a lot on labor-intensive construction activities. And a video about how important functions a pile frame is designed to perform will be interesting for anyone who plans to start building a wooden house in the near future.

What is a pile foundation? This is a certain number of linearly arranged elements that are in no way connected with each other. To combine the piles into a single structure necessary to form the foundation - the support of the building, it is necessary to equip each pile with a cap, on which a grillage or frame is then mounted.

Purpose of the strapping

A residential building does not weigh 2 kg, which means that the foundation must be reliable, monolithic, even if it is made from individual piles. A frame or grillage is necessary to evenly distribute the weight of the future building. A reliable coupling allows you to connect disparate piles into a single foundation body. In addition, the strapping aligns the top line of the piles into a single horizontal plane. This is extremely important for the stability of the house building structure.

Important! A pile-screw foundation is an excellent option for residential buildings made of timber, logs, and frame houses made of Sip panels. It is lightweight, environmentally friendly, cheaper, and installed faster.

In the field of low-rise construction, this type of foundation is more rational than other foundations in many respects.

Tying is a mandatory event. A pile pipe looking out of the ground is itself a shaky and unreliable element, but in conjunction with all the other pipes it can withstand heavy loads. The upper end of the pile is equipped with technological holes that are needed for installing a layer between the foundation (piles) and the building - this is the piping or grillage. The strapping is also a kind of protection of the walls of the building from the ground.

You can make strapping with different materials, but the best one for these purposes is timber. The rectangular shape facilitates installation work on creating a grillage and the initial stage of laying walls. Arranging a grillage using timber is recognized as the most effective among all strapping methods.

Features of the procedure

The grillage can only be made from solid wood, but it is possible to use laminated veneer lumber, which has technical characteristics superior to natural ones. Glued laminated timber is much more stable than solid timber, made by gluing under pressure elements with differently directed fibers, the material has increased resistance to environmental influences. The workpiece must be equipped with smooth side surfaces.

It is preferable to make the grillage from coniferous trees. Their advantages are long service life, that resinous wood is less susceptible to the harmful effects of moisture and biological pests, and it rarely develops fungal outbreaks or mold colonies. Wood is a warm material, a floor insulation cake starting with a wood base is much warmer than a similar cake, but on metal. Coniferous species are much cheaper than others, which is also an advantage. Installing the grillage is not complicated; all the work can be done with your own hands, saving money on this too.

Important! The beam must be smooth, not bent, without cracks, chips or any other deformations. The length of the beam is equal to the pitch length of the screw piles. The beams are fastened to each other in the harness only above the pile support and in no other way.

Beam connections in the harness

in half a tree, the connection occurs at a right angle, the beam from the end is selected halfway;
into the paw, the connection occurs at an acute angle, the timber is also selected from the end.

The sections of the joined beams should fit tightly to each other, mirroring the notch. The elements are secured using the following fasteners:

metal plates;
clamps;
corner;
staples;
bolts, screws, anchors.

To better understand the principles of docking, look at the picture.

Advice! When calculating timber for strapping, you should add 10-20% in case of defects or technical errors. It is undesirable to purchase additional material from another batch for a number of reasons.

To ensure that there is no doubt about the strength of the grillage, it is worth using the principle of double fastening and fastening the joints using several installation technologies.

Grillage installation

Installation begins with installing the caps on the piles. These can be metal plates, but for timber piping they use U-shaped flanges placed on the “head”, that is, the “U” is upside down.

The timber blanks are prepared in advance. At the ends, cuts are made corresponding to the connection in half a tree or in a paw. They also prepare grooves into which the logs will later be installed.

Important! The flanges are covered with roofing felt so that the wood does not come into contact with the metal.

The tying begins from the corners. The first two beams are joined at an angle of 90°; to be sure, the angle is checked and fixed with self-tapping screws. This is how I equip all 4 corners. Then continue tying on the sides. The joints are additionally fastened with plates or other fasteners and laid with jute to avoid the formation of cold bridges.

It is better to make a double harness, it is considered more reliable and durable. Double strapping technology, the difference is that 200x200mm timber is used for the first layer, and 100x150mm for the second. The top layer is placed on the smaller side, long side up. The cuts for the logs are made in the bottom row; the joints of the beams of the first and second layers should be spaced apart from each other.

Before you begin tying, you should check the quality of the installation of the piles; each of them must be installed strictly vertically.

Fastening with anchors, self-tapping screws, and tightening bolts must be done strictly in the center of the connection. It is advisable to use clamps; it does not lead to the formation of cracks.

It is necessary to make precise cuts; excess cuts will weaken the structure.

Important! There is an opinion that for a house made of timber there is no need for strapping, that its role is played by the lower crown, and the cuts for the logs are made in the upper crowns. The opinion is doubtful.

And lastly, if the piles are not screwed to the same level, you can screw the pile, cut off its top or bury the end into the strapping beam. If a crack appears in the beam, it needs to be replaced.

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. 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.

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Overview of strapping installation types and selection of tools

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.

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.

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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.

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Thread fit

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.

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Landing on clamps

The next stage of tying will be installation on clamps. This whole process is as follows. Long rectangular blocks 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.

After installing the piles for a rigid structure, it is necessary to carry out a strapping, which, in essence, is an overlap between the foundation and the house itself, and evenly distributes the load on the supports.

For the construction of bathhouses, log houses and other types of wooden houses on a pile foundation timber strapping is most often used; its price is significantly lower compared to metal strapping. The material can be coniferous or deciduous.

Coniferous timber is somewhat more expensive than deciduous timber, but it also has advantages over the latter: Such rocks have a longer service life, durability, high material strength, and good moisture resistance. Glued laminated timber has even greater strength indicators, but its cost is much more expensive.

To order tying piles or installing a screw foundation in St. Petersburg and the Leningrad region, request a call back and our managers will contact you.

Stages of installation of tying a pile-screw foundation with timber

As with any piping, you first need to make sure that the piles are installed at the same horizontal level.

All building materials are prepared - dried and treated with special solutions to prevent rotting and increase fire safety.

Corner elements are selected, a cut is made at their ends, and the “wood floor” or “claw” technique is used for locking connections; the sections should complement each other as much as possible to avoid distortions; if there are internal partitions, then they are connected to the external one according to the same principle.

A prerequisite is to check all directions of the bars (performed by pulling the rope), and the diagonals are also checked. All dimensions of the building will depend on how well the diagonals coincide.

After that, the timber frame is fastened through the pile heads with plumbing bolts 120 mm long and 10 mm wide. The bars are connected to each other with a bracket.

When fastening the beam, you should press it from above to avoid its displacement during drilling.

After the timber piping of the screw foundation is completed, a waterproofing layer is laid on top, and open areas are treated with mastic.

Tying the foundation on screw piles with timber can be single or double, the latter is considered more durable, since it does not require making cuts and lags. In this case, use the first crown with a cross-section of 200x200 mm, the second crown - 150x100 mm.

Sometimes tying screw piles with timber is not done. In this case, the role of the strapping is performed by the lower crown of the log house itself, which is installed directly on the foundation.

If you have any questions about the installation of the piping, please request a call back and our managers will contact you.

Our video on the topic:

1. Tying with timber using a non-standard method:

2. Raising the house. Replacement of piping and foundation:

2. Tying piles during the construction of a frame bath from SIP floors:

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 further speed up the work, pile-screw foundations are used as the foundation. The fact is that in the process of their arrangement there are no wet processes. To provide the foundation with proper stability, you will need proper tying of the pile foundation.

For the stability of a wooden house, it is not enough to drive the piles into the ground - they also need to be fastened together from above

Features of a 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 lightweight.

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 to uneven areas, when, due to the characteristics of the topography, this type of foundation is the only possible solution.

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

Cheapness. Other types of foundations are much more expensive.

Simple and fast construction. Special equipment is usually used to immerse screw supports, which allows this procedure to be completed in a few hours. There is also a manual screw option that can be handled by 3-4 people.

Screwing in screw piles using special devices will significantly save time

When laying a foundation using screw piles, labor-intensive excavation work will not be required. The main thing is to correctly calculate the depth of screwing 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 the structure does not have a continuous supporting surface. This causes known difficulties when using materials for small format walls. The current 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 building will depend on the strength of the pile foundation

Why do you need a harness?

The function of the strapping 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 being built from). The grillage cannot be considered a mandatory structural element of a pile foundation. Despite this, it is recommended to use it in every case, which guarantees the reliability and stability of the structure.

The grillage performs the following functions:

Evenly distributes the load on the piles. This is especially true for 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 an overall structure from individual piles. After this, the supports stop “living 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. A shallow and recessed grillage helps to increase the area of support on the ground and creates protection for the underground area from influences from the street.

Scheme of a pile foundation with a shallow grillage

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

Foundation piping is classified according to the type of material used:

Wooden from timber. It is used in the construction of wooden frame houses and timber buildings. The arrangement procedure is inexpensive and can be carried out alone or with one assistant.

Boardwalk. Small wooden and frame buildings are equipped in this way. To construct a grillage, the so-called a composite beam made from several wooden planks.

Metal. A channel grillage can 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. During the construction process, the concrete solution is poured into pre-assembled formwork equipped with reinforcing mesh.

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

Wooden strapping is used only for frame buildings and houses made of timber

Material selection

The pile foundation grillage is most often constructed from 200×150 mm timber. If the house being built has impressive dimensions, then it is better to use timber 200×200 mm. Using material 200x150 mm, it must be laid on the heads in a narrow part. Thus, the strapping beam will have a height of 200 mm.

Preparing the base of the heads

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

They must be prepared accordingly:

Drill several holes (usually 3-4 pieces). They facilitate the procedure of attaching wooden frames with plumbing screws. The size of the screws is 10x120 mm.

To attach the harness to the heads, holes are made for self-tapping screws.

Waterproof the caps with roofing felt or innovative bitumen material. When cutting pieces for each head, make a margin of 20 mm per side: this makes fixing easier.

Thanks to waterproofing gaskets, protection is provided for wooden framing elements from the damaging effects of moisture. Its source is condensation that forms on a cold metal surface during temperature fluctuations. Every 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 condensed moisture from penetrating the frame. This significantly increases its service life and prevents rotting. To prevent the waterproofing sheets from moving, the base of the cap is coated with bitumen mastic.

Waterproofing between the head and the timber is mandatory, otherwise, due to exposure to moisture, the strapping can quickly “wear out”

Fastening the bars

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

The procedure for installing the timber:

The starting point for installation is chosen to be fastening units in areas where the beams intersect with each other.

The joining of timber is usually done “in half a body”. Less commonly, a more reliable “claw” connection can be used. To ensure a tight fit of the timber, its ends must be cut as evenly as possible. The connecting areas are additionally coated with wood glue.

The timber is fastened to the base of the heads using self-tapping screws with a hexagonal head, 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 a body. Before this, the timber in the connecting areas is equipped with grooves.

Connection of grillage beams at the corners of the foundation perimeter

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

Additional fastening

For reliability, the elements of the connecting nodes are additionally fastened with steel brackets made of a metal rod with a diameter of 8 mm. This must be done when the length of the screws is not enough to firmly fasten thick beams. The location for installing the brackets is chosen to be the top part of the beam, opposite the connecting nodes. The sharp ends of the fasteners must be driven into solid sections of the timber that are not equipped with half-tree recesses.

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

Markings are applied. To do this, simply attach the fastener to the surface of the beam and trace it with a marker.

A groove 10 mm deep and 8 mm wide is cut along the marking line.

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 timber from cracking while driving the staple.

Holes and grooves must be treated with antiseptic impregnation.

Hammered staples should not rise above the surface of the beam

The staples are being driven in. They must be immersed flush into the surface of the timber

At the intersections of two beams, a “half-tree” joint is used. The self-tapping screws are screwed in from below. The staples (4 pieces) hammered in from above should form a square shape.

The installed brackets should not protrude above the general surface, otherwise this 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 horizontal structure

When the beam tying of the screw piles is completed, the finished structure is checked for horizontalness. To do this, use a water or building level. The permissible diagonal difference between opposite corners is no more than 5 mm. All parameters of the finished harness must correspond exactly to the instructions in the design documentation. The observed errors must be taken into account during the construction of wall structures.

Checking horizontality is a mandatory step; if you bypass it, you can get many problems with your house in the future

Bottom line

A pile foundation makes it possible not to depend on the characteristics of the soil and climatic conditions of the region. When it comes to building a light frame house, the piles are usually tied using timber.