How to break an old concrete foundation with your own hands

October 3, 2016 Stroyexpert Home page » Foundation » Repair

Dismantling secrets: how to remove the old foundation

Often, when purchasing a plot of land or inheriting it, you end up with a dilapidated house that can no longer be used. And if breaking the upper part of the structure does not present any special difficulties, then in order to remove the old foundation of the structure, you will have to suffer quite a bit. Not everyone knows how to remove the old foundation. Today we will talk about this.

Required Tools

The list of tools that will be needed to complete the task depends on the design of the base and the dismantling technology.

If the work is done manually, you will need:

Jackhammer (perforator);
Sledgehammer;
Scrap;
Cutter with diamond tool.

Mechanized dismantling methods will require the use of special equipment:

An excavator equipped with attachments - a drill, a hydraulic hammer, shears, etc.;
Hydraulic wedge;
Ultrasonic emitter;
Diamond cutter, disc or wire.

The above list cannot be considered exhaustive; in each specific case, additional tools and devices may be required. The most necessary tools are indicated, without which you cannot do without them.

Attention! Working with power tools can be very noisy, especially when using a jackhammer. It is prohibited to carry out such actions near schools, hospitals and kindergartens.

How is the cost of dismantling determined?

The cost of dismantling the old foundation is influenced by the following factors:

How deep is the depth?
Shape and dimensions of the foundation.
To carry out the work you will have to use a variety of special equipment. The price includes payment for its use.
The scope of work depends on the type of foundation with which work must be carried out. At the same time, dismantling a pile or reinforced concrete structure is more expensive compared to a columnar one.
The distance to the nearest buildings or structures is important. The closer they are, the higher the price will be.
In the process of removing the remains of the foundation, you will have to work with the communication system. The price depends on its vastness and density of location.

Dismantling the foundation is a complex set of works. When determining the price, all the main features of a particular job are taken into account.

Manual dismantling Source xn—7-jtbufr.xn--p1ai

Manual methods

The cheapest way, which will cost weeks or months of exhausting labor. It is very difficult to break a concrete block reinforced with thick reinforcement using a crowbar and a sledgehammer.

If the old foundation is made of brick or stone, then it is quite possible to break it manually. With some stretch, this method is suitable for a strip foundation, if the old house was not too large and its foundation is small. Slab and large strip foundations cannot be dismantled manually.

One of the effective methods is an explosion, but the presence of other buildings, structures and communications in the immediate vicinity, which does not allow blasting, forces one to resort to other, more gentle methods.

How to break the foundation

Dismantling secrets: how to remove the old foundation

Types of foundations and methods of their dismantling
Columnar brick foundation
Pile foundation with and without grillage
Reinforced concrete foundation
Mechanical methods for dismantling concrete
Manual dismantling of a concrete base
Scientific approach to solving the problem

Types of foundations and methods of their dismantling

The abundance of different types of foundations for a house or outbuilding does not imply the use of one universal method of dismantling. Let's look at the main types of foundations and how to destroy them using mechanical devices or on your own.

Columnar brick foundation

The simplest option for both installation and dismantling is a brick columnar foundation, which consists of several separate supports partially buried in the soil and protruding above it. It is made by laying it on a cement-sand mortar. Sometimes reinforcement is placed in the seam for strengthening.

Columnar brick foundation: diagram and implementation

In order to be able to break such a foundation, it is enough to have a construction chisel and a hammer or sledgehammer, since removing the foundation of such a structure is not difficult. The main task is to break the masonry joint. To do this, just place the chisel on the seam and hit the striking part several times. This way you can gradually break each old column.

Difficulties may arise when working with the underground part. To facilitate the process, you will need a simple bayonet shovel, which is used to dig around the perimeter of each foundation to the very foundation. After this, you can continue working. After removing all the supports, all that remains is to level the site as it was and you can use it at your own discretion.

Pile foundation with and without grillage

The next type of foundation that should be discussed in detail is a foundation on piles. The latter are cylindrical supports that are screwed or driven into the ground. Sometimes, to strengthen the pile caps, they are connected by a common bond made of wood, metal or concrete - a grillage.

They begin to break such a foundation by dismantling the top trim. The wooden and steel grillage is attached to the piles using bolts or welding. In order to conveniently remove such connections, you will need a grinder with a metal disc. It is used to cut off bolt heads or welding seams. How to break up a concrete grillage will be described in more detail below in the section on how to remove the old strip foundation.

Pile foundation with grillage: diagram and implementation

If a problem arises, how to break a foundation on piles, carefully read this paragraph. Steel screw piles are buried into the ground by screwing them in manually or using specialized construction equipment. It is also not difficult to remove them from the soil. It is enough to drill a through hole in the pipe of the old support, insert a piece of pipe of suitable diameter about two meters long into it and unscrew it, rotating counterclockwise.

The situation is more complicated with the process of removing driven piles, since it was only possible to remove the foundation from the site on such supports using special equipment - a truck crane or an excavator. Renting such equipment with a driver will cost a certain amount. You cannot cope with such a difficult task on your own.

Reinforced concrete foundation

The old concrete base is considered the most difficult to work with. Even a foundation that has stood for decades is very difficult to break. This is due to the structure of the concrete itself, consisting of a mixture of cement, sand and natural stones of the middle fraction - crushed stone, and the presence of steel reinforcing rods with a diameter of 10-12 mm in the frozen mass.

There are several main types of monolithic foundations. In construction you can find strip concrete foundations of one or another depth and slab foundations. The technology for dismantling them is the same.

Reinforced concrete foundation: scheme and implementation

Before breaking a concrete foundation, it is necessary to study all possible methods of dismantling it. They are divided into mechanical, manual power and physical, using the laws of physics. Some of them are more expensive, but allow you to remove the old foundation in a matter of hours, others do not require finance, but their implementation will take from several days to several weeks.

Mechanical methods for dismantling concrete

In order to make it possible to break a concrete structure, the following types of mechanical assistants are used:

Excavator with a set of hydraulic attachments (scissors, drill, jackhammer, hydraulic hammer). With one machine, you can remove the soil around the foundation, break the foundation into pieces, load them into trucks and fill the resulting trenches with soil.
A hydraulic wedge is specialized equipment used to break rocks and break concrete foundations. The device uses the ability of a liquid to transmit pressure applied to it in all directions evenly.
An ultrasonic emitter allows you to break concrete foundations by exposing them to high-frequency sound waves reaching 100 MHz.
Diamond cutting with disk or cable cutters allows not only to break the foundation into separate parts, but to obtain them of the correct geometric shape for further use in construction.

Manual dismantling of a concrete base

If you don’t want to spend your own money on work that you can do yourself, we’ll tell you how to break a concrete foundation on your own. For work, prepare:

shovel;
construction chisel (differs from a metalworking chisel by a much larger length);
sledgehammer;
perforator;
grinder;
wheelbarrow

We begin the work by digging in the concrete base so that it can be easily accessed along the entire perimeter. We remove the soil and put it in a dump nearby, since it will later be useful for backfilling the trench.

Carefully inspect the surface of the foundation for cracks. It is more convenient to start work from them. If you have a hammer drill, you can drill many holes arranged in rows in the transverse direction. After this, installing a pointed bit to make it easier to break the concrete, we break off the foundation in pieces.

It will not be possible to break steel reinforcement with a hammer drill. For this purpose, we cut the previously released rods with a grinder, observing safety precautions. Be patient, as it will not be possible to quickly remove the old foundation from the site manually. Small pieces of concrete base can subsequently be used as rubble stone when making a new foundation, installing a fence, etc.

Scientific approach to solving the problem

In addition to the listed forceful methods of influence, there are several methods that were used in ancient times and appeared relatively recently. The first uses the pressure force of wood when it swells. The method is not quick, the first results will be noticeable after 10-12 hours. It is better to use it together with subsequent power, since it will not be possible to completely remove the old foundation in this way.

To carry it out, wooden cylinders are driven into pre-drilled holes in the concrete. You can use cuttings of birch cuttings for shovels or carpenter's dowels. A plastic cup with a hole in the bottom is attached to each of them and water is poured into it. The principle of operation is based on the gradual swelling of wood and its expansion of layers of concrete. In Ancient Egypt, megaliths for the pyramids were broken using this method.

The second method appeared in the 80s of the last century. It consists of using an expansion of certain chemical compositions. On sale you can find non-explosive expanding materials of the brands NRV-80, NRS 10, which are fine powders.

To prepare the working solution, the substances are diluted in water in a certain proportion and poured into pre-drilled holes in rows. After some time, the concrete can be easily broken into pieces. This method is convenient from the point of view of preserving the peace of neighbors, since it is very rare to break an old foundation without noise.

Cutting reinforcement

Reinforcing bars located inside concrete strips or slabs cause a lot of trouble during dismantling. They must be cut as they are removed from the thickness of the concrete, otherwise after a while it will become impossible to break through the frame.

It will not be possible to do without cutting, since the work will simply stop as the first reinforcement bars are exposed. Conversely, if the reinforcement is removed, the concrete will break and be removed much more easily.

The rod is cut using a grinder, specialized scissors and an excavator tool.

Construction equipment

The most effective types of construction equipment used for dismantling foundations include:

Excavator. A construction machine capable of developing greater power and performing a variety of types of work. To dismantle the foundation, attachments are used - a hammer, scissors, a drill, a chisel. Convenient for loading debris and debris when cleaning an area.

Hydraulic shears. A mounted tool capable of cutting through reinforcement or thicker metal profiles, crushing concrete and slabs.

Hydrocline. A tool that destroys a concrete monolith using water hammer energy. Liquid is pumped into a pre-drilled hole, in which high pressure is created, bursting the concrete mass. The productivity and power of such a tool are extremely high. For the destruction of powerful slabs, such a tool is the optimal choice.

Diamond wire cutting. A special rope in the form of a loop wraps around a section of a concrete block and is threaded into a rope machine. When the rope moves, the concrete is cut without a large amount of dust, the formation of microcracks and debris. The use of this technology is limited due to the high cost of work. The specifics of cutting are not entirely convenient for dismantling foundations.

Concrete destruction methods

During construction, it is often necessary to destroy old concrete structures.

Concrete is a very durable building material, because it supports the entire house. Therefore, many builders are wondering how to destroy concrete. This can be done in several ways:

When planning an apartment or building, for example, you need to destroy a wall, a hand-held hydraulic tool that can destroy concrete up to 15 cm is ideal. Or a light series jackhammer.

A small structure can be split with a sledgehammer; in particularly difficult places, a hammer drill can be used. This is a rather difficult method that will require physical effort. A particularly strong foundation cannot be destroyed in this way.
You can destroy concrete by using a special acidic mixture. This is the most common method.
Non-explosive substances are often used, for example, NRS-1 powder.
The methods for destroying reinforced concrete are slightly different. Conventional methods will not work here. Only cutting with a special diamond wire is effective.

In order to understand which method is suitable for your case, you need to familiarize yourself with each of them in more detail.

Easy way

Options for the type of destruction of concrete and reinforced concrete structures.

A small structure can be crushed into pieces with a sledgehammer. The speed of destruction in this case will depend only on your physical capabilities. If your physical capabilities are small, then this will take a lot of time and effort. You can drill holes in several places with a hammer drill, then the strength of the material will decrease and it will be much easier to break it. It is believed that it is quite possible to crush a reinforced slab with a sledgehammer, but is it worth doing this if there are other easier ways?

Destruction with powder

Very often, chemical powders are used to destroy solid building materials. They are non-explosive and non-flammable. The popularity of this method is due to the fact that during the destruction process no excess debris is formed and there is no noise, as happens with a regular explosion. NRS-1 powder is widely used. It has a high fracture force (more than 30 MPa).

The method of using the powder is quite simple. To begin with, holes are drilled in the structure. Then powder mixed with water is poured into these holes. The diameter of the holes should reach 8 cm. The distance from one hole to another should be at least 56 cm. The substance poured into them will crystallize and destroy the building material. You need to wait two days for complete destruction. After this time, only pieces of scrap can be found at the foundation site, which can be easily transported to the disposal site.

Sour mixture

Calculation table diagram: destruction of concrete when exposed to a high-speed jet.

Everyone knows the harmful effects of acid on concrete. Therefore, an acid mixture is often used to destroy durable structures. She simply dissolves it. If it is necessary to remove a small amount of solid matter from a surface, it may be sufficient to simply pour acid on top of it. For example, salt. You need to act very carefully so as not to get burned or damage anything else. But acid in its pure form is used very rarely; usually a special mixture is made. It helps to dissolve concrete, clean bricks from it, and wash off excess from the wall. The mixture consists of concentrated acids and inhibitors.

Inhibitors are necessary to prevent damage to another surface along with the concrete. For example, if you need to clean a frozen concrete mixer. This mixture quickly penetrates deep into the material and destroys it so that after some time it turns into dust, easily swept away with a regular brush. If some time has passed and the building material has not yet been completely cleaned, the mixture can be reapplied.

Use of mixtures

An alternative way to destroy concrete is to use special mixtures (for example, NRS-1).

When not in use, it is a white powder. It is diluted with water to a maximum of 35%. The principle of operation is based on the expansion of the mixture with which the holes are filled. Changing the volume of the mixture leads to splitting of monolithic concrete blocks.

The force developed by the mixture during expansion allows it to destroy the most durable and hard types of concrete.

Order from specialists

Independent dismantling is not accessible to everyone. The problem arises in the work itself, which requires a certain number of people and equipment.

The foundation, broken into pieces, must be removed, and removal of the debris is an equally labor-intensive task, including loading and transportation.

The ability to attract a team of specialists becomes a significant bonus, reducing time and labor costs. This will cost a fairly large amount, but these expenses will be fully justified.