Step-by-step instructions for installing a pile-strip foundation

Establishing a robust base is essential for any building endeavor. Combining the benefits of pile and strip foundations, the pile-strip foundation is one practical choice. Because it provides stability and support, this hybrid approach can be applied to a variety of soil types and structures.

It is imperative to comprehend the correct installation of a pile-strip foundation, regardless of whether you are building a house, a garage, or an extension. Because this kind of foundation evenly distributes the load, there is less chance of it settling or shifting over time. It is particularly helpful in regions with difficult ground conditions, like sandy or clay soils.

We’ll walk you through every stage of the installation procedure in this article. You will acquire the knowledge required to confidently take on this project, from site preparation to the finishing touches. You can guarantee a strong foundation that will support your building for many years to come by following these instructions.

Step	Instructions
1. Planning	Choose the location and size of the foundation. Ensure it meets local building codes.
2. Site Preparation	Clear the area of debris, vegetation, and topsoil. Level the ground as needed.
3. Marking	Mark the perimeter using stakes and string to outline the foundation.
4. Digging	Excavate trenches for the strip foundation and drill holes for the piles.
5. Installing Piles	Place piles in the drilled holes and secure them with concrete.
6. Reinforcement	Lay reinforcement bars in the trenches and connect them to the piles.
7. Pouring Concrete	Pour concrete into the trenches and pile holes, ensuring even distribution.
8. Curing	Allow the concrete to cure for the recommended time before proceeding.
9. Inspection	Check the foundation for any issues or deviations from the plan.

What is a pile-strip foundation

A supporting structure called a pile-strip foundation is made up of a network of piles that are submerged in the earth until they come into contact with dense layers. Concrete tape is used to tie the piles together, distributing the weight of the house evenly between the piles and the ground.

The tape’s shallow immersion depth aligns with the typical shallow-depth tape base parameters.

In contrast, piles are submerged beneath the soil’s freezing point to guarantee a sturdy and unyielding foundation.

Because both components are firmly fixed to one another, they form an unbreakable, sturdy framework for the house.

There is only one system used as the tape and piles’ reinforcing belt. In the event that submersible or screw piles are utilized, the armored belt is welded securely to them.

The load in this instance is split equally between the piles and the tape; taken separately, they are unable to support the weight of the structures and the pressure from the soil.

Advantages and disadvantages

The following are some benefits of pile-tape foundations:

• Possibility of use on problematic soils.
• To build such a foundation, a relatively small amount of building materials is required.
• High resistance to soil influences – heaving, small movements.
• Some types of piles can be created directly on the site, which can significantly reduce the cost of purchasing, delivering and burying them in the ground.
• It becomes possible to build in areas with high groundwater levels.
• High construction speed.

Additionally, there are drawbacks:

• Before starting construction, it is necessary to carry out a thorough comprehensive survey of the site regarding the composition of the soil, the height of groundwater, etc.d.
• There is no possibility of creating a basement or basement.
• High-quality insulation of the floor of the lower floor laid on the ground is necessary.
• There is no possibility of constructing multi-storey buildings.
• Piles must be properly waterproofed. This is especially true for wooden or steel supports.

Since the majority of the flaws are caused by the characteristics of the soil, these aren’t so much shortcomings of the foundation as they are necessary constraints imposed by the current circumstances.

Scope of application

Low-rise private buildings can be constructed with a pile-strip foundation.

Large, heavily-weighted multi-story buildings need more robust support. For them, the piles’ dimensions have to be enlarged, and the tape’s load-bearing capability is no longer required.

A pile-grillage foundation is a similar option used for heavy buildings.

Although the two types of foundations are nearly identical in structure, they are not the same because in a pile-tape foundation, the load is distributed equally between the piles and the tape, whereas in a pile-grillage foundation, the piles are the load-bearing elements and the grillage serves only to distribute and transmit the load.

When building a belt on problematic soils, the type of base under consideration is the best compromise option because it adds extra reinforcing elements without requiring labor-intensive and time-consuming work.

What soils are they used for?

On complicated and troublesome soils of different kinds, pile-strip foundation is utilized:

• Loose.
• Possessing a complex composition and layering.
• With high groundwater levels.
• With multiple moisture-carrying layers.
• Heaving.

Furthermore, the pile-strip foundation works effectively when constructing on relief folds or slopes where it is not feasible to conduct extensive excavation work for a variety of reasons. In these cases, the relief’s shape—which determines the parameters for selecting a basis—rather than the soil’s composition is what matters most.

Types of pile-strip foundations

The kind of piles used in conjunction with the tape varies amongst all varieties of pile-tape foundations.

Existence

• Screw. Metal pointed pipes with blades installed at the bottom. Immersed by screwing into the ground using the principle of a screw. Allows you to operate manually in close proximity to neighboring buildings.
• Bored. Piles are poured directly on site. A well of the required depth is prepared for pouring, into which a reinforcement cage and waterproof formwork (polyethylene or asbestos cement pipes) are lowered. Sometimes the walls of the well are used as formwork (if the soil allows).
• Submersible. Ready-made piles are used, which are driven to the required depth using a construction pile driver. The work requires certain conditions, so there are some restrictions on the degree of proximity to neighboring buildings, the possibility of special equipment approaching the site, etc.d.

Furthermore, there are various ways to submerge the tape:

• Recessed. This option is used in the construction of fairly massive houses. The tape is immersed below the soil freezing depth, which requires large volumes of excavation work and the absence of aquifers. This method is rarely used due to the inexpediency of installing additional supports – if the site conditions allow the construction of a buried belt, then its load-bearing capacity is quite sufficient for any structure.
• Shallow. Most common option. On average, the tape is immersed to a depth of 30 cm with an open base of 50 cm. The volume of excavation work is small, but it requires precise accounting of the groundwater level and the presence of seasonal changes.
• Shallow. In essence, this is a pile-and-grillage foundation. It is pointless to support the strip on heaving soil, since the loads in such conditions have a maximum value. The strip usually rises above the zero mark, which automatically stops its work as a supporting structure, leaving only the role of an intermediary between the piles and the house.

In actual use, the strip is most frequently utilized in a shallow version with bored piles.

It offers a lot of benefits.

• Minimum excavation work.
• Ability to do without the use of construction equipment.
• All elements of the foundation structure are created directly on the site, which facilitates transportation and unloading.
• You can act independently, without involving expensive specialists.

In any event, a thorough survey and geological justification for the proposed work must be completed.

Design

A pile-strip foundation is designed with several piles positioned with a specific pitch along the strip’s central axis. These components are combined into a single mechanical system by the rigid connection between the reinforced tape belt and the pile reinforcement frame.

Digging a trench and drilling wells are two tasks that are done concurrently or in phases during excavation work. The belt is constructed in accordance with the general guidelines, except that extra reinforcement cage elements are present.

There are two conditional stages to all work:

• Creation of a pile system.
• Filling and holding the tape.

While pouring all the components of the supporting structure at once can maximize the base’s strength and solidity, it is not always possible to combine or complete both points at the same time.

Installing a pile-strip foundation is the best option for uneven or difficult soil conditions because it combines the stability of a strip foundation with the deep support of piles. This tutorial will take you step-by-step through the entire process, from site preparation and planning to concrete pouring and drainage checks. Having a thorough understanding of each stage will help you guarantee a strong and long-lasting foundation for your project, regardless of the size of the building. You can create a stable and long-lasting foundation for your construction by paying close attention to detail and following safety regulations.

Laying depth

Since the piles and the tape are submerged at different depths, the laying depth in this instance has two meanings.

The degree of occurrence of dense layers and the characteristics of the soil determine the depth of immersion of piles.

The trench’s depth is estimated to be between 50 and 70 cm based on the thickness of the backfill layer and the relatively shallow depth of the tape, which is about 30 to 40 cm.

These are the average values that happen most frequently; the numbers are provided conditionally.

In order to complete the work, qualified experts must be brought in to survey the site, determine the foundation’s dimensions, and provide precise immersion level values for each element.

How to choose a step between piles

The weight of the building, the load-bearing capacity of all components (both tape and piles), the properties of the soil, and other considerations are compared to determine the spacing between piles. Calculation process is very complex; doing it on your own is not advised.

Online calculators can provide you with the answer in a matter of seconds if consulting an expert is not an option for the calculation. For the answer to be as accurate and correct as possible, it should be repeated on multiple resources.

In reality, bored piles, or steps of two to three meters, are the most popular choice. Both manual computations and online calculators yield close values. Pitch increases in piles may result in load transfer to the tape, which may then cause the concrete belt to deteriorate and sink.

Step-by-step instructions for installing MZLF

Work schedule for constructing the MZLF:

• Site preparation, removal of top soil layer, marking.
• Digging a trench.
• Installation of piles.
• Laying a sand cushion.
• Assembly and installation of formwork.
• Assembling the armored belt, connecting it to the piles.
• Concrete pouring, curing.
• Final procedures – insulation, waterproofing, pouring the blind area, etc.d.

The foundation with driven piles is depicted in the diagram; suitable adjustments are made for other types.

Marking and driving piles

After the trench is prepared, the pile field is marked out. The corners hold the initial installation points, with the remaining locations distributed evenly along the perimeter’s sides based on the design data. Following marking, the piles are submerged to the necessary depth.

Strong vibrations are produced because special equipment (a construction piledriver) is used for this purpose. Diving is risky if there are other buildings nearby because ground movements can cause houses to suddenly sink.

Harness

Tying piles involves a number of procedures:

• Trimming the tops to create an even horizontal field. If necessary, some piles are built up.
• At the top points the piles are connected by metal beams.
• The beams are connected to the reinforcing frame of the tape.

The process may vary slightly from the above depending on the kind of piles. For instance, bored piles are just joined with tape and a cage for reinforcement before concrete is poured into a single monolith.

Installation of formwork

To avoid moving bulky shields over great distances, the formwork is assembled as close to the trench as feasible. Typically, formwork is made of edged boards measuring 25–40 mm. Boards are thicker if the tape is wider and higher.

The panels’ width marginally surpasses the fill’s height. Gaps must be avoided and assembly must be done as tightly as feasible. It is imperative to give the formwork the utmost attention because its strength guarantees that there won’t be any leaks of concrete.

Transverse struts are used to fix the panel position from the inside, while vertical and inclined stops reinforce the formwork from the outside.

Reinforcement of the foundation

Concrete structures can have their tensile strength increased with reinforcement. The working (horizontal) rods are calculated to be 2–5 cm below the concrete’s surface when creating a reinforcement frame.

To do this, a spatial grid made of smooth auxiliary rods installed in the shape of clamps and functional ribbed rods 10–12 mm thick are required. Only at the filling stage does vertical reinforcement become necessary; after that, it just stays within the concrete mass.

Knitting reinforcement

The knitting method is used to join the reinforcing bars. The steel wire is soft.

Knitting procedure:

• The wire is cut into pieces according to 25-30 cm.
• A piece of wire bend in half and place under the connection point of the rods.
• The ends of the wire are raised up, grasping the crosshairs.
• A special hook is inserted into the loop and rotated around the other end. Usually do 4-6 revolutions.

The process is easy, and even those who have never knit reinforcement before almost instantly pick up the skills. The bond is sufficiently strong and tight.

Pouring concrete

Concrete is poured all at once and as rapidly as feasible. Extended breaks exceeding a day are not recommended as the concrete will solidify and prevent additional pouring.

Although the connection won’t be as strong as a monolith, you’ll have to wait until the material dries completely before proceeding with the work. Concrete must be evenly distributed and poured at various points along the length of the tape.

In order to accomplish this, you must plan ahead for the approach routes and create a flexible tray that enables you to precisely direct the flow of concrete to the appropriate locations.

The substance needs to be cleared of air bubbles after pouring. What is the purpose of a continuous bayonet or vibrating construction machine?

Final stages of work

To shield the filled tape from rain and the sun’s intense rays, it is covered in polyethylene. For the first three days, the tape is watered every four hours to equalize humidity and reduce stress. After that, watering is done three times a day for the next seven days.

After pouring, the formwork is typically removed ten days later, and the material is completely dry after 28 days.

Exposure must be conducted strictly in compliance with technological specifications. Since the foundation’s strength is too important and prevents liberties, no deviations or initiative should be permitted.

Waterproofing and insulation

The tape is waterproof and, if needed, insulating once the concrete hardens.

All surfaces are waterproofed using a variety of materials, including:

• Hot tar.
• Bitumen mastic.
• Ruberoid.
• Impregnating compositions.

Manufacturers assert that impregnations are the optimal choice. Builders use tried-and-true techniques and like using bitumen mastic.

In situations where there is an abundance of moisture and heaving soil, the foundation must be insulated. The process entails firmly applying heat-insulating tape to the surface (penoplex is the best option for the foundation). An alternative is to use polyurethane foam that is liquid.

It provides an entirely waterproof and sealed insulating layer. The tape must be installed both inside and outside, which uses more materials but maximizes insulation effectiveness.

Useful video

Additionally, a video explaining the column-tank foundation and providing step-by-step instructions on how to perform all the processes by hand can be viewed and familiarized with:

When carried out meticulously and methodically, installing a pile-strip foundation can be a rewarding project. You can guarantee a sturdy and steady foundation for your construction by carefully following the step-by-step instructions. To prevent problems later on, it’s critical to begin with a complete site analysis and precise measurements.

The process of installing the piles and joining them with a strip foundation after the groundwork is ready supplies the required strength and support. This combination works especially well on uneven surfaces because it evenly distributes weight and can work with different kinds of soil.

It is important to pay attention to materials and techniques. The longevity of the foundation is increased by using high-quality concrete and reinforcing materials. Furthermore, if you follow local building codes and safety precautions, your project will be safe and legal.

Ultimately, a well-built pile-strip foundation raises the value of your home in addition to offering stability. This foundational work creates the framework for a successful building project when planned and executed correctly. Recall that the foundation pays off in the long run when time and effort are invested in it.