URETEK's technology | URETEK

Soil compaction and leveling – an important step to prevent the building from subsiding

The foundation is one of the most important, if not the most, part of a building. The entire building relies on the foundation, and its durability determines the durability of the entire thing. The foundation of the building has to be built so that it withstands the weight and load of other elements. A building’s and its foundation’s construction starts with preliminary work, which can not be ignored.

Preparing the soil by its compaction and leveling, is an important part of the construction process. This gives it the required flat base that offers an important support not only for the building, but for roads and other different building constructions as well. The compression process gives the soil, that is under the foundation, a bigger endurance and stability. It is important to know why this process requires careful attention and what could happen, if this step is skipped or carelessly executed. And most importantly- how to deal with consequences that have occurred from poorly compacted and leveled soils.

What is soil compaction?

Soil compaction and leveling - an important step to prevent the building from subsiding

The majority of constructions are supported by soil that is underneath them. To enable construction of a building or other facility, air and water particles must be removed from the soil and then it has to be leveled. That way the treated soil can sufficiently and firmly support the construction.

Soil compaction means increasing the density of soil, sand or some other solid soil layer by pushing out water or air from it. This is done by applying load to soil with the help of mechanical means. This way the soil’s volumetric weight and carrying capacity increases, which ensure the load receptivity coming from the building.

The compression’s main goal is to increase the shear strength and the related load capacity. Through the process however, the stiffness of the soil is also increased to prevent future deformations, for example through moisture content and frost.

The result from the compressions depend on many different factors such as:

  • The nature and type of the soil – it can mean compositions from sand, clay, soil or granular;
  • The thickness of the compacted soil layer;
  • The moisture of the soil;
  • Time, that is spent on compaction;
  • Of the work that is done for compaction- the weight, type, vibration, number of repetitions etc of the used device

What is soil leveling?

Soil leveling, as the name itself says, means leveling the ground, to remove bumps, dimples or other bigger unevenness. The operation is carried out in the preparation phase of the new construction project.

One of the main purposes of soil leveling is to protect the foundation from water damages. Leveling the soil under constructions or around it, ensures water from flowing away from the building and not into the soil layer under the foundation. If the soil layer is not leveled or is poorly done, the water can flow towards the house. This can gather around the foundation and saturate the surrounding soil, causing the building to become unstable.

Afterwards, it is possible to carry out soil work around the house. For instance on properties, where the missing drainage ruins the foundation, leveling the soil can repair the situation.

Why is soil compaction important?

If proper geological studies were not done before building a house and the house is built on a weak land, or the land has been poorly prepared before building a foundation, as in compacted and leveled, it can lead to the process when the soil as well as the house start to subside.

A subsidence is a process that is a result of the environment, as a result of substandard works or due to changes in the soil, the building’s foundation could move downwards. Land subsidence can be caused by geological, manmade or seasonal reasons:

  • High spring waters can wash away a lighter layer of soil, such as sand;
  • Bigger trees that grow near the foundation can, especially during hotter periods, suck out moisture from the soil so much that it could cause the soil or other soil layer to contract;
  • Water that has flown out from a broken or leaking sewage, can sometimes soften or even wash away the ground surface, resulting in a movement of the ground and therefore the building;
  • If a building is near a high traffic area, the strong vibrations coming from it could lead to ground movement.
  • Foundation works, that have been done with poor quality, could cause subsidence problems, especially during water damages.

Although, reasons why a house’s foundation or floors subside are different, they are still frequently caused from the very first building steps. For this reason, it is very important to be cautious about the soil’s compaction and leveling.

What does house subsidence entail?

Different cracks in the inner and outer walls, gaps between the floorboards and the walls, sloping or partially sunken floors, slanted or jammed windows and doors are just a few concerns that subsidence can bring up.

Over time subsiding foundation can bring up serious problems:

  • Damages to walls and floors are harder to repair or they are even irreversible;
  • Cracks that have become bigger and bigger over time allow wind and moisture to enter the house, causing mold over time;
  • Heat loss increases, the dwelling is colder and as a result the energy efficiency of the building decreases;
  • Water and heating pipes can break;
  • Malfunctions of electrical installations can occur.

Problems that are caused from the house’s or foundation’s subsiding are expensive. A lot of money is frequently spent on repairing damages, but the core of the problem is not dealt with and no work is undertaken to stabilize the foundation.

How to deal with the consequences of poorly compacted soil?

Soil subsidence. Land leveling with URETEK technology

If for any reason the foundation of the house has begun to subside and as a result the whole building has started to do the same, the problem must be dealt with as soon as possible. Then neither the soil leveler nor the surface hardener will help, you have to approach subsidence in a different way.

Stopping the house from subsidising and restoring the foundation using conventional methods is a time consuming and resource-intensive job. Solving the problem with the outdated approach means emptying the rooms, breaking up and removing the concrete floors, compacting the soil and pouring new floors. This puts the owner of the house in front of a difficult question- should they start a time- and money consuming process that forces them to be away from home for a long time, or postpone the solution of the problem into the indefinite future, knowing that the situation will constantly worsen? This way it seems like the only thing left is to make a bad or worse choice.

If only there was a solution that thickened and stabilized the building quickly and cleanly and would not need additional preparations such as moving out of the house and replacing furniture. What if the cracked walls and cracks between walls and floor tiles could be fixed in a day, without waiting for the new concrete to harden? Seems too easy of a solution to be true?

How can URETEK help?

Works performed by the soil improvement enterprise URETEK are, due to their innovative technology, a highly valued alternative for raising and restoring building foundations or floors. This does not require excavation or demolition, thus contributing to both human comfort and environmental protection. Also the technology developed by URETEK does not cause vibrations or disturb nearby buildings.

URETEK uses injection technology of geopolymers, which allows it to approach the mentioned problems in a new and convenient way. URETEK offers a technological solution, with which two component geopolymer resins inject the ground. The nature of the problems in soil, which is the cause of subsidence of the foundation and floors, is reached through a 12-32mm wide borehole and an ecologically neutral resin or geopolymer resin mixture is injected into it. The resin is inserted into the soil where it expands until it hardens, filling all the voids and cavities in the soil. Under the influence of resin injection, the house or other structure rises up and moves back to the original designed height. The soil layer is compacted and thereby ensures the stability of the building.

It is not required to move out of the house or even move furniture for this type of procedure. Daily use of the building may continue during the works. Usually it only takes one to three days to complete the work and the work site remains clean and dust-free.

Get in touch with us and we will stop your buildings from subsiding.


The foundation – should you build a new one or insulate the old one?

foundation construction and insulation

Building a foundation

Older houses hold a special feeling, character, and history within them- something you can’t find in a new one. This is the main reason why people choose to renovate the old house. There are different ways to renovate- there are houses that will only need their windows replaced, stairs built and interior touch-ups, while some houses need to be built from the ground, starting with the foundation. 

The foundation is the bottom layer of a house. Whether it be a foundation for a log house or a greenhouse– it carries the weight of the whole building. A secure and reliable foundation is a lot more than just the bottom of the house. It keeps away humidity, isolates the outside colder temperatures, and prevents the ground from moving around it, acting as an anchor between the framing of the house and the ground beneath it. That’s why the foundation of the house will be the first project to take on when you begin the renovation of your house. 

Even newer houses have problematic foundations. Old houses often have been built using different techniques and materials that have not lasted through the test of time. It shouldn’t scare people, who would like to own an older house, but it is something to pay attention to. 

There are different severe signs that show the necessity of foundation work. Such as cracks on the floors and walls, trouble closing doors and windows, unleveled flooring, heat loss, water running in, and as a result moisture damage.  

Building a new foundation for an old house 

Most people who buy an older house, take the need for a renovation into consideration. It’s a widespread practice to change out the roofing and windows. But building a brand new foundation is something that not many have heard of. Even though that is not the most regular choice, it is not a rare occasion where that step is necessary. 

Building a brand new foundation for an old house is usually chosen by very reasonable concerns. It does require a bigger budget, more time, and thorough research beforehand. But if the old house has gotten serious damage then building a new foundation is the best and the only way you should start planning your home’s renovation, to guarantee the stability and longevity of the house. 

Slab foundation, post foundation, or pile foundation 

Once the decision to build a new foundation has been made, the next important choice has to be made. Which foundation should you choose? The classification of foundations is based on the construction, the way of working and building, the construction depth, and calculation methods. Let’s look at the three most used foundation types. 

  • The slab foundation is very durable and covers the whole base of the construction, stopping it from moving and changing the house’s construction. A slab foundation is built above the ground with special L-shaped blocks and then it’s filled with reinforced concrete. You have to consider that to achieve the traction of the concrete, you have to reinforce it. A slab foundation works great with single-story houses and it doesn’t require too much digging work. This type of foundation has to be insulated. 
  • The set-up of a post foundation is usually fast and simple. It works well even in low quality and softer grounds. Posts are inserted with certain techniques deep in the ground. Usually, a post foundation is used for smaller buildings, such as sheds, greenhouses, and garden houses. But it works great for a bit bigger summer houses and log houses. 
  • Pile foundation is the most popular type of foundation in Estonia It requires good soil and ground, and a lot more digging work. In this case, reinforced concrete, stone blocks or limestone are built deeper than the freezing point, following the outer and load-bearing walls of the house. It works great for bigger and heavier houses, also buildings that need a basement. 

There are more foundations – for example, a pile foundation or a foundation built of fibo blocks. The choice of a foundation depends on many factors – the soil, the size and weight of the house, but also the financial possibilities and time. There is a lot of information about different types of foundations, and if you are interested, you can find a lot about them on the Internet.

The price of the foundation

The prices for the construction of the foundation vary – whether you need a post foundation for a small cottage or a pile foundation for a bigger house. However, the price of a pile foundation is generally cheaper than, for example, a slab foundation. The price of a new foundation may also include soil preparation and excavation work, insulation of the foundation, installation of underfloor heating pipes, installation of sewerage pipes, and much more.

Based on the prices found on the Estonian Hange.ee website, the prices of the pile foundation for a smaller modular house start at 6,500 euros. The price of a slab foundation for a house of more than 100 m2, together with the additional work that goes into it, can be as high as 30,000 euros.

House renovation and foundation construction - where to start?

Insulation of an old foundation 

If the construction of a completely new foundation is unnecessary during the renovation of an old house, the foundation works cannot be forgotten. Due to poorly or incorrectly insulated foundations and floors, the heat loss of a house can be as high as 20%. Therefore, insufficient insulation on the foundation means high heat loss and higher energy consumption for heating the home. A properly insulated foundation also reduces and prevents moisture from entering the house. However, moisture can lead to mold, rot, or even flooding. For these reasons, you need to pay attention to the foundation and, if necessary, instead of building a new foundation, the old foundation should be insulated. There are many tips on how to insulate a foundation.

In addition to the insulation of the foundation, the waterproofing and insulation of the external walls and floors, whether on the ground or not, must also be double-checked. Read more about the steps of renovating a house.

What should be used for the insulation of an old house? 

The foundation is usually insulated horizontally, but nowadays it is also done vertically to ensure even better thermal insulation. There are several ways to insulate a foundation.

The easiest way to do foundation work and insulation are if the house is not on the foundation. In this case, the foundation can also be approached from above and covered entirely with insulation boards, such as expanded polystyrene boards, up to the freezing point. When renovating an old house, this option is not possible, in which case attention must be paid to the type of foundation.

PUR foam is well suited for insulation if the foundation is laid with earth- or limestone. In the case of a stone foundation, it is wise to approach the insulation from the outside, in order to keep moisture away from the stone wall with proper waterproofing layers. Whichever option has been used for laying the foundation, it should also be used for restoration and insulation work.

When deciding how and with what to start insulating the foundation of an old house, first of all, you have to look at what and how the existing foundation has been built. The location of the house, the surface, and the damage to the foundation must also be taken into consideration. In addition to insulation, attention must be paid to directing water and moisture away from the foundation and the house using waterproofing layers or drainage.

The price of foundation insulation 

Just like the insulation of the foundation depends on many factors, so does the cost of it. Access to the foundation, the amount of heat loss, the material, the quality of the soil, and the size of the foundation are some of the factors that must be taken into consideration when finalizing the price. We can see from the hange.ee website that the insulation of the foundation pricing starts from 1000 euros and when combined with other work, it can reach up to 25,000 euros.

What if the old foundation has subsided? 

raising the foundation
Even if the foundation is new and well insulated, there can be unexpected problems with it. Subsidence of the foundation is a process in which the foundation starts to move downwards due to the environment (as a result of poor quality work or changes in soil properties). The cracks in the walls and the gaps between the floorboards and the wall indicate the subsiding of the foundation or floor of the house. If such changes occur in both the new and the older house, the foundation work cannot be postponed and must be addressed immediately to avoid further damage. Lifting concrete and finding leveling solutions and concrete raising systems are required. Concrete lifting solutions are needed to fix that problem. URETEK’s geopolymer technology is a great way to approach such problems easily and effectively. No need to lift concrete slabs, use heavy concrete slab lifting equipment, concrete slab jacking equipment, or concrete raising equipment. Using URETEK’s technology, it is not necessary to dismantle, dig, transport heavy, large-scale materials or use heavy trucks during the work process. Read more about
lifting the foundation or ask for an offer from our website.


Subsidence of the floor! How to lift the foundation?

Subsidence of the floor. How to recover or lift the foundation and the floors?


Renovating an old house can be even seen as an exciting hobby with the same goal for the whole family – to restore a house that will be turned into their new home. This process often takes years, if not decades. When renovating, the list of things that need to be repaired is often long enough to leave the smaller things in the background. The priority of work seems to be divided. This is how a small crack in the wall may go unnoticed at a first glance. However, that small crack, which initially looks like a beauty flaw, can be a sign of something bigger – the foundation or floors of the house are subsiding. In that case, concrete lifting is needed. That may require different concrete leveling equipment depending on the project, such as concrete hoisting equipment, concrete lifting hooks, concrete pipe lifting equipment, precast lifters, precast lifting clutch or concrete panel lifting clutches. It is clear that this work needs professional help.

For the most part, owners of old houses have taken into consideration that unexpected and unpleasant setbacks may arise that will require immediate action and extra cost. Owners of new houses expect that the time and material costs will be much lower. However, the subsidence of the foundation and floors, unfortunately, more often than we assume – is also a concern for new houses. A decrease in the efficiency of underfloor heating in a new building may indicate the subsidence of the floors, but there may be other similar problems that also arise with old houses.

Help – my house’s foundation is subsiding!

The recovery of a subsided floor and foundation

Any cracks in the interior and exterior walls, gaps between the floorboards and the wall, sloping or partially subsided floors, jammed windows and doors are situations that can indicate a serious danger to the entire house – the foundation of the house is subsiding! The subsidence of a building is a process where the foundation of the building begins to move downwards due to the influence of the environment, as a result of poor quality work or changes in the properties of the soil. In this case, foundation or concrete lifting is necessary! There are many options for that. Lifting precast concrete, concrete floor lifting, cement slab lifting or precast lifting are just some of them. 

At first, it might seem like raising and stabilizing the foundation is not needed because major damage and longer-term problems are not immediately apparent. However, urgent action is needed on this issue. The subsidence of the foundation will lead to more serious concerns over time:

  • damage to walls and floors will be more difficult or even irreversible to repair;
  • cracks that become larger over time allow wind and moisture to enter the house, creating mold over time;
  • heat loss increases, the house is colder and becomes less efficient;
  • water and heating pipes can break;
  • problems in electrical installations occur.

A lot of money is often spent on repairing the damage, but the core of the problem is not addressed and no foundation stabilization work is done. In this way, various worries start to reoccur, requiring more costs on house maintenance. The most effective way to protect a building from major damage is to stabilize it and restore the foundation to its former state. You can do that by hiring a professional to help you out. Special equipment is needed for cement lifting, foundation lifting, or concrete driveway lifting. 

There are many reasons why the foundation and floors of a house have started to subside, and they often arise during the construction of the house. Here are some of the reasons:

  • no proper geological surveys were carried out before the house was built and the house was either built on weak soil or the soil was poorly prepared before the foundation was built;
  • the house was built without the installation of drainage;
  • the foundation is overloaded due to incompetence in the reconstruction;
  • water supply, sewerage or heating systems have weakened the soil;
  • in the event of the subsidence of the floor, the base surface has not been properly compacted during the foundation.

How to repair the subsidence of the foundation or the floor?

If it has been established that the foundation and floors of the house are subsiding, it is necessary to think about raising the building. For someone who has never heard of restoring and raising a foundation before, such work can seem like a very time-consuming and big project to take on. One may wonder if such a thing is possible at all and how big of a crane is needed for it? You might be left alone with a feeling that you have to choose between bad and worse. You can start with the tasks that are the most time-consuming and money-consuming or postpone solving the problem to an uncertain future while knowing that the situation is getting worse?

An easy solution would be to pour concrete over the subsided floor surface. This might seem like a good way to level floors. In reality, this can cause more damage, as fresh concrete adds new weight to soft ground and subsidence can continue even more intensively. Secondly, the building cannot be used while the concrete is drying.

The recovery of a subsided floor and foundation

Removing people or workers and things from the house and dismantling and reassembling the tools seem like a big task to take on. That is why raising and stabilizing the foundation should not be postponed.

What if restoring a foundation, raising a concrete floor or a log house, or stabilizing a building is actually a clean and quick process that does not require additional preparations such as moving out of the home? What if the cracked walls and cracks between the walls and the floor tiles could be fixed in one day, without having to wait for the new concrete to harden?

These are the questions that URETEK Baltic, a leading geopolymer soil remediation company in Baltic countries, has answers for. URETEK uses geopolymer injection technology, which allows for an innovative and convenient approach to the above-mentioned problems. URETEK’s technology has a wide range of applications and can be used to raise concrete floors, lift the entire log house or even an apartment building, level the ground, and stabilize the foundation. The technology offered by URETEK’s specialists ensures fast, convenient, and environmentally friendly lifting of the building, and the problem can be solved without disturbing the customer’s daily life and business.

How do URETEK’s geopolymers help to raise and stabilize the foundation?

Due to innovative technology, the work carried out by URETEK´ is a highly valued alternative for raising and restoring the foundations or floors of buildings. Such technology has many advantages over conventional methods, which are more complex from both a human and an environmental point of view. Geopolymeric injection differs from conventional building lifting procedures- it does not require excavation or demolition work, thus contributing to both human comfort and environmental protection. Also, URETEK’s technology does not cause vibration or disturbance.

When using the geopolymer technology offered by URETEK´, the subsidence is stopped quickly. The essence of soil problems, which is the cause of the subsidence of the foundation and floors, is reached through a 12-32 mm wide borehole, and an ecologically neutral resin or geopolymer resin mixture is “injected” into it. The resin is introduced into the soil, where it expands until it hardens, filling in all gaps and cavities in the soil. During the resin injection, the house or other structure will rise higher if possible and return to its correct position. It is not necessary for people to move out of the house or even remove furniture from the building for this procedure. The building can continue to be used during the work process. It usually takes only one to three days to complete and the work area remains clean and free of dust.

The material that is used is a patented geopolymer resin blend. In order to increase the load-bearing capacity of weak soils, the unique expansion properties of the geopolymer resin mixture can be used, which quickly and efficiently restores the building to its original condition. Geopolymer is a strong, insoluble and time-resistant material that doesn’t damage the building’s structures. Geopolymer resins can fill any surface.

Lifting and leveling of the foundation

It may be thought that the polymer, as a chemical, could have a toxic effect on the soil or contaminate the water in the soil. URETEK’s technology has been used for more than 40 years. A number of scientific studies and experiments have been carried out on the safety of these materials. The results confirm that the fear of pollution is not backed up. The materials are safe for both humans and nature. Everything is regulated and certified according to European standards

URETEK’s technology is seen as an environmentally friendly approach. As URETEK’s technology does not require demolition or excavation to lift the foundation, does not require the transport of large materials or the use of large vehicles- it reduces CO2 emissions, saves resources and preserves nature. If there is a need to dispose of material, the process is no different from disposing of other building materials. Just like bricks, concrete or other construction materials, polymers are regulated construction waste that must be disposed of at construction waste collection points.

So it is confirmed that the procedure carried out by URETEK saves time and money and is an environmentally friendly solution to the problem of the subsidence of the load-bearing structures of the building.

Under standard conditions, URETEK provides a 2-year warranty for the work performed, and the material itself has a warranty of 10 years. At the same time, experience shows that objects stabilized 40 years ago remain solid and secure to this day.

The price of URETEK’s service depends on many factors, from the nature of the problem to the size of the foundation of the object. Visual assessment of the problem, consultation and initial underground inspection of the object are free of charge. After a visual inspection and inspection of the underground soil, a personal price offer is prepared for each customer.

URETEK´s team offers a free professional consultation to assess the condition of the load-bearing structures of the building.

URETEK Baltic compacts the soil

Stages of soil compaction:

  1. Visual inspection and survey by URETEK’s specialist, during which, the initial survey and inspection are carried out in order to understand the size and nature of the problematic area. After the visual observation and survey by URETEK’s specialist, an initial price offer can be made for the client. Visual observation and survey are free of charge for the client.
  2. If necessary, the soil under the flooring is inspected. In case, that the problem is more serious, a hole is drilled in the floor with the consent of the client, and a camera will find the empty spots under the floor, which have caused the floor and the building to subside. The initial underground inspection is free of charge for the customer.
  3. Geological research is done if necessary – in some cases, it is also necessary to carry out geological research of the soil to map out the state of the soil, which can be ordered by the client or with the help of specialists of URETEK Baltic. A geological survey shows what soil is under the building, how deep is the problem, and what is the nature of it.
  4. If the terms and the final quote work for the client, a time plan is agreed upon with the client, and work begins.

Compacting, leveling and lifting a subsided soil


Elimination of floor subsidence in stores and warehouses without changing their opening hours

Concrete floors of large warehouses, supermarkets and logistics centres may also suffer from subsidence or tilting

Modern URETEK geopolymers injection method allows lifting concrete floor slabs and stabilise them without vacating the premises and disrupting daily work.

Floor slabs in large warehouse and commercial areas are designed in view of daily impact of stationary structures. Concrete floor must also handle loads caused by loading machinery and other warehouse equipment. In case of exceeding permitted maximum static or dynamic loads or in case of changes in soil properties under the structure (weakening of soil due to changes in surface water level, breakage of water or sewerage pipes), it is likely that floor slabs sink or tilt.

The damage described above can cause minor discomfort resulting from changed position of commercial and warehouse equipment, but it can also lead to accidents and situations that endanger human health and life.

Complexity of lifting and stabilising concrete slabs

Unfortunately, subsidence of concrete floor in a warehouse or commercial premises is not always noticed in time. Considering that restoration of concrete floor and strengthening of the soil under the floor requires dismantling of concrete slabs when using traditional methods, the repairs are often postponed as they cause major loss to the owners of premises resulting from long-term work stoppage.

Instead of applying systemic measures, owners often seek temporary solution by using all kinds of supports and bases. However, such an approach to the problem may obviously lead to unpleasant consequences.

Lifting and stabilisation of floor by using geopolymers

Sunken sections of concrete floor can be lifted and the soil under the structure can be strengthened by using URETEK geopolymers injection method.

In that case, there is no need for dismantling concrete slabs, involving heavy machinery or performing earthworks. In order to stop subsidence of concrete slabs and levelling them, geopolymer material has to be inserted deep under the floor in the soil under the structure (Deep Injection method) or in the space between soil and concrete slab (Slab Lifting method).

Immediately after injection, geopolymer resins expand and take up all vacant space in the soil under the structure, compact the soil and harden within only 15 minutes. URETEK geopolymers injection technology allows increasing compressive strength of soil up to 10.6 МPа.

Injection can be done without dismantling sunken slabs. It requires drilling just a few technical holes with diameter of 16mm in the concrete for pipes intended for inserting geopolymer material. Meanwhile, URETEK equipment can be located up to 120 m from the actual place of injection.

Geopolymer material is inserted in soil through special hoses that can easily be moved in the room between shelving and other equipment. Thus, it is not necessary to vacate premises from goods and equipment. Furthermore, the hardening speed of URETEK geopolymer resins allows lifting and stabilisation of concrete slabs at night. But warehouse or store does not have to stop work even if the floor needs to be lifted during working hours. Due to mobility and compact dimensions of the equipment, there is only minimum disturbance in daily operation.

Advantages of URETEK technology

The process of lifting and levelling sunken concrete slabs is monitored in real time. This is done by using special laser levels with measurement accuracy of ± 1 mm. Ground floor slabs can be lifted by maximum 20 cm. After restoration of former floor height, cracks can be eliminated in partition walls supported by sunken slabs. Restoring floors by means of URETEK method allows saving up to 25% compared to traditional methods.


Stabilistaion of concrete floors in industrial and utility rooms

The floors of industrial and utility buildings may subside over time

Covering consisting in concrete slabs are often damaged at joints or become curved due to large load. Thanks to geopolymers, concrete floors can be repaired without disrupting the operation of the facility.

Subsidence of concrete floor slabs in buildings is allowed only to certain extent. When building such floors, all appropriate preparation works must be performed prior to assembling concrete slabs. However, in case of defective floor assembly or excessive loads on concrete floor, the premises need urgent repairs. Otherwise, sunken, deformed and tilted concrete slabs will obstruct normal work process.

Strengthening and repair of concrete floors

Slab Lifting method is used for stabilisation, lifting and strengthening of concrete floors. This method enables complete repair of concrete floor with the shortest possible time. Furthermore, it does not require dismantling concrete slabs, shelving and installed equipment, which saves much more time and money compared to traditional repair methods.

Slab Lifting method stands out by the fact that when injecting geopolymer resins, the load on concrete floor slabs are no longer considered a disadvantage, but an advantage instead. In some cases, it is even recommended to install new equipment in the room and only then commence lifting and stabilising concrete floor slabs. When concrete floor is exposed to additional load, it is much easier to direct the pressure generated during injection of geopolymer resins into deeper soil layers. This allows better quality of soil compaction and strengthening of concrete slabs.

How concrete floor is levelled

Repairing concrete floor by means of Slab Lifting method allows quick commissioning of restored floor sections. There are no work stoppages that otherwise occur when dismantling and re-installing concrete slabs. Therefore, using this method has minimum effect on client’s business activities.

For lifting, stabilisation and levelling of concrete slabs, geopolymers are injected under the concrete surface through 1–142 mm holes. Geopolymer components are mixed in special compact devices at the time of injection. Almost immediately after reaching the soil, geopolymer components undergo chemical reaction which makes the material expand. The material fills all hollow cavities under the concrete, force liquid from the soil under a structure into other soil layers and expand towards the weakest parts of the soil.

Soil is strengthened at the distance of 500 mm from geopolymer injection point. A new layer with increased load-bearing capacity is formed in the process, which allows lifting the concrete slab. The process of lifting and levelling of the slab is monitored in real time with accuracy of ± 1 mm.

Stabilisation of floor in cold chamber

Cold chambers in warehouses stand out by strict requirements for insulation, including floor insulation. It is not always easy to insulate the floor when converting existing premises into cold chambers. Using geopolymers when levelling and strengthening concrete floor has an indirect effect of improving floor insulation.

The reason for that consists in the fact that geopolymer used for strengthening and compacting the soil spreads evenly under the concrete and forms a hermetic layer with low thermal conductivity. Thus, in addition to strengthening the concrete floors in cold chambers, geopolymers allow reduce the costs of floor insulation.


Using URETEK technology for solving problems with industrial and construction platforms

Frequently, the equipment on construction and mining platforms lacks reliability due to their poor quality or ineligibility for particular operation. However, the problem may often be related to land subsidence.

Even the smallest deviations occurring in soil due to subsidence may cause disruptions in the operation of machines and mechanisms that require precision and cause excess burden on such equipment. Eventually, such situation may cause remarkable disturbances in operation and be costly in monetary terms. Ignoring the problem may lead to breakdown of the equipment, resulting in work stoppage and costly repairs (technical maintenance), loss of productivity and, in some cases, risk of danger.

First signs of potential problems

Division operator is recommended to check the alignment of equipment. Frequent deviations include:

  • Unusual noise generated by equipment;
  • Abnormal wear and tear of equipment, especially in case of conveyor belts and crane tracks;
  • Excess wear and tear of tracks and surfaces under equipment due to excess vibration that causes land subsidence.

The most common causes of subsidence (gradual collapse, compaction or sinking of ground surface) include problems related to drainage, poorly compacted filling material and mechanical vibration.

It is crucial to apply early countermeasures

It is always advisable to stop land subsidence before equipment fails, as it allows minimising expenses related to work stoppage and repairs. By using modern soil technology methods, it is much easier and quicker than people would think. For instance, URETEK resin injection technology is a reliable, convenient, effective and cost-efficient alternative solution instead of traditional methods such as concreting or cementing. URETEK technology involves using low pressure to insert resin in unstable soil or rock that has fallen apart or suffered structural damage due to compaction, in order strengthen it. Operative and effective URETEK technology can also be applied in a situation, where it is impossible to intervene in the operations on construction site. Depending on volume, the procedure may take a few days and it can be performed parallel to construction works and without taking breaks. That’s what makes the method so flexible.

Light and yet durable resins used in URETEK technology are sustainable, have low environmental burden and help performing variety of technological and geotechnical tasks. Areas of application include e.g. decommissioning of fuel tanks, underground storages, water pressure pipes, stormwater pipes and tunnels, also filling large cavities, voids and even abandoned mines with bulk material.


Comparison of concrete works and URETEK technology. Pros and cons

Causes of deformation in building foundation

Formerly, foundation was repaired by cementing, now a new solution is used – URETEK technology. It represents a rapid and secure alternative to concreting and piling of foundation. URETEK technology deploys unique strengthening methods for foundation repairs, somewhat similar to advanced surgery. This technology allows eliminating the reasons for structural subsidence and deformation by re-levelling slab covering of concrete foundations, strip foundations, pile foundations and floor slabs and even solving problems related with access roads.

Work process

URETEK resin is inserted in the soil under a structure through small holes (usually with diameter of 16 mm, only 12 mm in case of interior works).

Then URETEK resins expand, filling cavities, compacting subsoil and stabilising the foundation (or other load-bearing structures), thus allowing re-levelling of the house.

For optimum results and safety purposes, the pressure generated in the course of expansion is constantly checked with laser equipment.

  • Cracks in the walls usually shrink. However, in case of brick wall, it only requires secondary treatment of joints with mixture or joining with special fixture, patching and painting of cracks in case of plastered walls.
  • Windows and doors will usually function normally again.
  • Gaps between floor slats and fixed floors generally disappear as well.


Materials used comply with strict ecological and safety requirements and have been designed specifically to resist drying and subsidence. Quality is guaranteed for more than 50 years.

Strengthening methods using concrete works

Over many years, concrete works have been used as a classical method for foundation repairs. Compared to traditional concrete works, the advantages of URETEK technology include speed, cleanness, durability and predictability, economic efficiency and an opportunity to avoid interfering with normal use of the structure.

URETEK material ensures durable soil stabilisation and building re-levelling faster than concrete works, where nothing can be guaranteed. Now it is possible to heave a house to desired height within a day or two, or a couple of weeks, depending on its construction technology. Furthermore, resin injection does not generate waste, there is no need for excavation works, water, cement or concrete.

It is important to mention that injection works do not require vacating entire room. Unlike concrete works that need lots of preparation and interior works, URETEK technology does not need any of that. Small holes (diameter of 12–14 mm) can be drilled between cover plates and even through carpeting and there is usually no need for moving the furniture.

URETEK method is ideal for foundation repairs even in case of clay and other porous soils, as it solves subsidence problems. The method ensures load-bearing capacity of substrate and uniform properties of load-bearing layers.

In the course of concrete works, it is necessary to improve poor soil conditions, such as unbound, dusty and wet substrate or substrate containing poorly compacted filling material. This is due to the reason that extra weight of concrete may further aggravate the situation.

Cost of concrete works

Besides being more convenient, safer and durable, URETEK injection solution is usually also cheaper than traditional concrete base.

The cost of concrete works depends on many factors, including:

  1. Location of building,
  2. Actual cause of the problem,
  3. Properties and condition of the soil under a structure,
  4. Type and profile of building foundation,
  5. Surroundings, e.g. access to the plot, adjacent buildings and support walls,
  6. Unknown, unpredictable condition of the soil under a structure,
  7. Quantity of required material,
  8. Time spent on work.

If only one corner of the house requires re-levelling, concrete base may be cheaper, but it may still lead to further problems over time. For instance, new cracks may develop in the house if concreting is performed in only one section of the foundation, not to mention additional load on the base affecting the substrate that was used to former loads.

In most cases, resin injection is cheaper than other methods, including concreting of foundation.


Restoration of historical monuments

Sites of great historical and cultural value are threatened by natural ageing and going to ruin just like any other structure.

Sites belonging to national and global cultural heritage must be restored or reconstructed to keep structural damage to minimum, be it then repair of walls and floor or lifting and strengthening of foundation. Damage of historical buildings can be minimised by using URETEK geopolymers technology.

Manor buildings and palaces, castles and fortresses, churches and temples, but also many other sites of historical interest age, break down and go to ruin. Condition of walls, roofs and ceilings of the building is affected by constantly alternating external factors: pressure, temperature, humidity and airborne gases.

Equally dangerous are changes in soil on which the site of historical interest has been erected. Thus, weakening of soil under the structure may cause subsidence of ground floor and reduce stability of foundation, which leads to damaging other structural elements of the structure.

Complications related to strengthening soil

Subsidence of foundation and floor of sites of historical interest often causes occurrence of cracks in floor and walls. In that case, simple cosmetic repairs of walls and floor are not enough to improve the situation, because the cause of cracking is not eliminated. Without improving the condition of substrate and lifting foundation or floor, the situation continues to worsen and may ultimately result in complete destruction of architectural monument.

Although sites of historical and cultural interest are generally renovated by using state-of-art technologies and building materials, lifting of floors and strengthening of foundation in these structures is often performed using traditional methods. However, traditional technology along with involvement of heavy machinery and concrete and earthworks may damage the site of historical or cultural interest.

Elimination of cracks in the floor and walls of an architectural monument, as well as strengthening of substrate and lifting of foundation or floor is much more efficient when using URETEK geopolymer resins injection technology. That technology makes it possible to perform works without affecting the historical and cultural value of the site and also reduces the budget for repair and restoration procedures.

Provided technology

There are two URETEK geopolymers injection methods that can be used for strengthening the soil under historical monument and eliminating floor and foundation subsidence – Deep Injection and Slab Lifting. In the first case, geopolymer material intended for strengthening the soil and lifting the foundation is inserted deep into the soil under the structure, in the second case geopolymer is inserted immediately under ground floor.

Geopolymers are injected in soil or under the floor through special pipes with diameter of 12–16 mm, inserted in holes drilled in ground floor or soil around the perimeter of the building. Borehole diameter may be 12–32 mm. No other interventions are required on the site. The equipment for injecting geopolymer resins is compact and mobile. Using it has no effect on the historical or cultural value of the site. Injection holes can be easily eliminated later on.

All procedures performed with URETEK geopolymer resins, be it then strengthening of soil, securing or lifting foundation or floor, do not take long. After injection, geopolymer material expands, filling all cavities in soil and hardens within just 15 minutes, exerting vertical pressure. Lifting of foundation and floor is monitored in real time by using laser level.


Stopping subsidence of concrete pools and elimination of cracks

Water level may drop in concrete pools. In hot summer, it is sometimes explained by natural vaporisation. But it may also result from occurrence of cracks in pool structure due to foundation subsidence.

Problem can be solved by using geopolymers injection.

Unlike other structures, pool structure does not prescribe even minimum subsidence of concrete frame. If the pool subsidence has occurred due to insufficient compaction of soil or excess humidity of the soil under the structure, cracking of concrete is inevitable. As a result of cracking, water starts to leak gradually. This, in turn further aggravates the condition of soil around the pool. It may become unsafe and the site cannot be used any more.

When repairing a pool, just patching the cracks is not enough. It does not remove the initial cause of damage. If the cracks occurred due to weakening of soil under the structure and subsidence of pool frame, it is necessary to address the problems with soil and foundation first.

In that case, soil is strengthened before eliminating cracks, foundation lifted and stabilised if necessary. It is worth noting that when using modern URETEK geopolymers injection methods, the work cycle lasts only a day or two and it does not require earthworks or concrete works.

Deep injection

Cracks in concrete pools can be eliminated by using Deep Injection method, which allows filling cavities and voids in the soil under the pool with special geopolymer resins. After reaching the soil, geopolymers expand and harden quickly, exerting vertical pressure. That way it is possible to strengthen weakened and excessively humid soil under the structure.

Furthermore, geopolymers can be used to stop pool subsidence and stabilise its position, or even lift it to its former height where necessary. Due to their structure, geopolymers do not react with water, but force it into surrounding soil. Therefore, geopolymer resins not only strengthen the soil, but also function as waterproofing material.

Cracks in concrete can be patched only after strengthening soil and stabilisation of foundation.

Works algorithm

Geopolymer resins are injected through special holes (diameter of 12–16 mm), drilled in concrete or soil around pool’s perimeter. Holes are quickly closed after completing the injection.

URETEK geopolymer resins are not destructive. They are suitable for strengthening soil, lifting and levelling concrete structures. Everything related to altering the position of concrete frame is monitored in real time by using laser level (precision up to ±1 mm).

Due to their physical and chemical properties, geopolymers remain stable for a long time, including in humid environment. Material is chemically inert, ecologically safe and tested across the world during long term use.


Resistance to cracking of reinforced concrete structures

Resistance to cracking is definitely observed when studying the durability of reinforced concrete structures. Builders can ascertain the resistance of the studied material to various internal and external factors. This indicator is expressed by the amount of time until the occurrence of first cracks. The longer the period when the structure remains intact, the greater the resistance of material to cracking. Crack develops when the stress factor significantly exceeds material’s permitted threshold value.

Accurate estimation can be obtained only by expert assessment of concrete samples. That currently most efficient method of study predicts future durability of the structure.

Factors affecting resistance of concrete to cracking

Occurrence and progression of minor defects in concrete can be induced by external factors – humidity and temperature – as well as the properties of the material itself. Determination of resistance to cracking takes into account information regarding the quality, flexibility, creep, settling and other properties of the material. Important factors include structural form and dimensions of the building.

Furthermore, the technology of manufacturing the cement must be considered. Materials with low hardening speed develop cracks less frequently cracking. That is why determination of resistance to cracking is a rather complex process and requires versatile analysis.

Options for increasing resistance of concrete to cracking

Even the appearance of small cracks in concrete structures is considered rather dangerous. Minor damages may cause cement to chip off, leaving the fixture exposed. This leads to corrosion, which causes further degradation. Concrete can be made more durable by using the following methods:

– using additives with special strengthening properties;
– magnetisation of water;
– inspecting the composition of concrete;
– covering the surface with iron;
– installing a special protective layer to avoid occurrence of small cracks;
– creating concrete with the best possible structure for particular purpose.

Optimum concrete composition requires using correct ratio of chosen components, which makes the concrete structure more durable.

If the crack has already occurred

Prior to repairing concrete structures, it is important to ascertain the cause of cracks. Restoration works can be divided in two:

– repair of structural defects;
– erection of new structures to replace the damaged parts.

Injection method represents optimum way of removing cracks. Special mixture is inserted in the problem area by using pressure. Where it is necessary to restore protective layer, shotcreting method is used. In that case a special construction mixture is prepared, which is then applied to prepared surface under pressure.

If the defects occur due to the soil, the problem needs to be solved urgently by strengthening or stabilising the subsoil.

URETEK specialists have everything they need to analyse, repair and restore concrete structures. When you contact us for help, every client may consider all their problems solved.