Rubble stone foundation: how to lay, advantages and disadvantages, tricks and tips. Rubble foundation for a house Flagstone foundation

The foundation made of rubble is reliable and aesthetic, its service life is at least 150 years, and the upper limit is not limited. After all, buildings made using the same technology several centuries ago have survived to this day. When building with your own hands, the most important thing is to choose quality stones, sort them correctly and follow the instructions.

Rubble - stones with uneven edges of different sizes and shapes, obtained by natural destruction of rocks (sandstone, dolomite, shell rock) or blasting. The average size of the fragments is 30-50 cm in diameter, weight – from 25 to 45 kg.

Types by shape:

torn - all edges of the fragment are uneven and sharp;
bedded - one of the sides of the cobblestone is smoother and more even;
flagstone - flat, arbitrarily shaped with even opposite sides.

This classification is conditional, since the stone is simply sorted based on the shape created by nature or rough mechanical action; no special processing is performed. Especially large cobblestones are sometimes split into pieces.

These stones are used to make foundations for any buildings, strengthening the almost chaotic masonry with cement mortar. In such a structure there is about 90% rubble. Cobblestones are placed in rows in a trench and secured with concrete. It is more convenient to use bedded and flagstone types. The high base is reinforced with a reinforcing belt. The rubble concrete foundation is suitable for any buildings several floors high, the construction of a basement, outbuildings, baths. It can be used to make a strip and column structure.

One of the most important criteria for choosing this material is availability. In regions with mountainous terrain, it is easiest to buy stone, but delivery to remote locations can be very expensive. It is also necessary to select a cobblestone with high level strength - when hit with a hammer, it should not crumble, but only make a ringing sound. Cracking and delamination are unacceptable.

Pros and cons of buta

No columnar or strip foundation it will not be reliable and of high quality if the advantages and disadvantages of the materials used are not taken into account when laying it.

Aesthetic appearance. The part that rises above the ground looks like stonework, giving the building a presentable appearance. Does not require additional finishing.
Environmental Safety.
Withstands temperature changes and exposure to moisture.
If the technology is followed, seasonal soil movements are not dangerous.
Durability amounts to hundreds of years.
The large load-bearing capacity allows the construction of large structures in area and number of floors from heavy products.
Not susceptible to fungus, mold and insect damage.

The construction of a rubble concrete foundation is far from a simple process, requiring time and physical effort. This is due to the characteristics of the material and technology:

The stones have different shapes and sizes; to place them as densely as possible, sorting and careful selection of elements will be required.
The rubble base must be buried 20 cm below the soil freezing level, so you need to dig a deep trench and gradually lay rows of cobblestones.
Construction in regions remote from the location of the stone is much more expensive due to the delivery of material.
All work has to be done with your own hands, since it is impossible to use special equipment.
Concreting is carried out in stages, so several portions of the cement mixture have to be mixed.

If it is not possible to carry out the work on your own, you will have to hire a team of installers. Masonry by professionals is much more expensive than the construction of other types of foundations.

Step-by-step instructions for laying a rubble foundation

You should make a plan for the location of the tape or pillars, sort the stones by fraction and shape. The smoothest and largest ones should be left at the corners. Study the structure and type of soil, establish the places of passage groundwater and the level of freezing - this is necessary to determine the optimal depth. Most often, 1.5-1.8 m is enough; in areas with a harsh climate and moving soil, they are buried 2 m. It is not recommended to use trench walls as formwork, as they will crumble, deform and take a lot of moisture from the raw concrete. Therefore, the width of the ditch with a tape thickness of 0.5-0.6 m should be at least 2.5 m. This is enough to install formwork on both sides.

The technology provides two methods:

Rubble. Laying stone in rows on mortar is similar to brick. With this method, most of the volume is bottled. To implement it, you need to select the most even flat fragments of different sizes and try to place them at the same level.
Rubble concrete foundation. Concreting with rubble, it occupies less volume and serves as reinforcement, and is located less orderly. Cobblestones are selected in the middle fraction up to 30 cm.

A solution should be prepared from a grade of cement not lower than M400. To improve plasticity, it is recommended to add liquid soap or dish detergent. The ratio of the main components is classic - 1 part cement to 3 parts sand. When constructing a rubble concrete foundation, fine crushed stone can be introduced. The consistency should be such that the mixture penetrates well into all voids, but does not spread much.

You will need a set of tools: sledgehammer, hammer, building level, shovel, twine, trowel. To fill the voids, it is advisable to prepare small crushed stone or pebbles.

Preparatory work

Preparing the site for a strip foundation or rubble pillars involves clearing the site of debris, uprooting stumps, bushes and trees. If the relief is uneven, it is corrected by removing the top layer or raising the masonry to different heights above ground level.

Next, lines are marked and the depth of the trench is determined. For large volumes of excavation work, it is better to carry out using an excavator. Sand is poured into a 15 cm layer at the bottom of the ditch and compacted - it will serve as a pillow. The specifics of further stages depend on the type of base.

Installation of formwork

The formwork is made from removable and non-removable bars and boards or panels. Since wood absorbs moisture, waterproofing from a thick film or roofing material will be required - it is attached to the walls of the frame and placed on the bottom.

Install gradually for ease of use. After installing one layer, some of the boards are moved higher. For a concrete base, the frame is installed at once to its full height and is not removed upon completion of work.

Method 1: laying rubble.

Careful sorting by thickness will be required. The general principles are to do the dressing as in the case of bricks, to place the largest and most even pieces in the corners, it is allowed to use large cobblestones in some places that will block two rows at once. Layers of stone are placed alternately with the short and long sides.

Instructions for strip foundation:

Pour concrete 3-5 cm thick into the bottom of the formwork.
Place large cobblestones in two corners of the trench and install a beacon made of twine - this will serve as a level for the first row.
Lay the flattest elements in two layers, fill the resulting voids with fine gravel.
Pour in the next portion.
Each subsequent row of rubble-tape base is laid before the cement sets; the position of the stones can be adjusted during the process.

When the work is completed and the foundation has dried, the formwork is removed, the ditch is filled with sand or soil, the upper part is waterproofed, and a blind area is made.

Method 2: concreting with rubble.

The solution takes up more space, and the stones are sorted only by size. It should be poured one at a time to avoid delamination.

Instructions:

At the bottom of the trench, make a cushion of sand and crushed stone and compact it.
Pour 20-30 cm of mixture.
Lay the first layer of rubble and drown it ⅔ into the DSP. The stones should not touch the walls of the formwork so that they are completely immersed in the solution.
Remove air cavities and bubbles using vibration equipment or a rod.
The layer rising above the ground, or the last 50 cm, is made using reinforcement and without cobblestones.

The formwork is not removed to ground level; the panels are dismantled only above it. The upper part is laid with waterproofing and a blind area is equipped.

Articles

Rubble foundation Any home craftsman can lay it with his own hands. And he will not need any special equipment or any specific knowledge. It is enough to understand the simple technology of constructing rubble stone foundations.

Experts say that rubble foundations for various buildings have been erected for more than 4 thousand years. In the Middle Ages, durable and aesthetically attractive rubble was used to make reliable strip foundations not only for houses, but also for powerful fortresses and defensive structures. Structures made from this stone last 150–500 years, demonstrating unique performance properties.

Rubble foundations for houses are absolutely environmentally friendly. They perfectly resist the effects of soil water and do not lose their characteristics when frozen.

Reliable foundation made of rubble

A rubble base is understood as a strip structure built from natural large-sized stones, which are filled with cement-based mortar.

This natural material is not divided into separate categories based on its size. For this reason, it may contain fractions with different geometric parameters - from 15 to 50 cm.

To build a foundation for a house, it is recommended to use stones with relatively wide and even upper and lower edges. Such material is usually called bedded. But it is also possible to use stones that are less correct in terms of geometry. Their shape does not affect the strength of the constructed foundation in any way.

Nowadays, rubble is most often used to build foundations for 1–2-story houses, as well as for various commercial buildings. The technology for constructing standard five-story residential buildings from rubble stone has existed for more than 60 years. A minimum of financial resources are spent on the construction of such buildings, due to the low cost of natural materials.

It is impossible not to separately note the natural beauty of natural stones. You can use them both to build a solid foundation for your house and to furnish the basement of your home. In the latter case, you will not have to spend money on finishing measures. The rubble base does not need to be plastered or tiled. It will look truly luxurious anyway.

On clay soils, high-density loams and sandy soils, rubble foundations last up to 150 years without any repairs. If such a foundation is being built on heaving ground that is prone to subsidence, the structure should be strengthened with reinforcing elements. And it will serve you for the same 150–200 years.

The quality of rubble for laying foundations for residential buildings is determined very simply. You just need to hit the stone well with a regular hammer. If the bottle does not break from a strong blow and at the same time produces a clear and ringing sound, it means that you have excellent material in front of you.

Stones are also checked for quality by splitting them. If you break the rubble, and it does not generate dust and does not break into small fractions, feel free to use it to build a foundation. Believe me, a foundation made of such stone will last for many decades.

Rubble house foundation

The rubble must be washed before laying. This procedure, let’s say right away, is labor-intensive. Please be patient and have some free time. You have to thoroughly wash every stone. If this is not done, the concrete mixture will not bond with the stones at the proper level, which will significantly worsen the strength of the foundation.

Large pieces of rubble for laying the foundation of a house require additional preparation - breaking them into smaller stones weighing no more than 30 kg. This procedure is called plinting. It is done with your own hands using the following technology:

Using a soft pencil, draw a line on the stone along which you plan to break the rubble.
Stretch the nylon rope and forcefully press it into a piece of pre-prepared chalk.
Pull the cord marked with chalk over the line marked on the stone and suddenly release the rope. As a result, you will get a clearly visible chalk mark on the rubble. This is where the material needs to be split.
Use a hammer to drive a steel chisel into the cut line on the rubble. You are splitting a stone. The hammer blow should be performed quite strongly. Do not be afraid. A high-quality stone, as we said, will not crumble, but will clearly separate into separate fractions along the split line.

Now that the material has been prepared, you can proceed directly to laying the foundation for the house.

The laying of the structure we require is carried out in several stages:

Clearing the land.
Dig a trench of the required size. The ditch must be made with a small margin. Maintain a distance between the boundary of the future foundation and the edges of the walls (load-bearing) of the house being built at a level of 15–20 cm. The depth of the trench is below the freezing mark of the ground in your area.
You do. It will protect the ditch from soil falling into it. The formwork structure is dismantled immediately after pouring and setting of the concrete mixture.
Place a 30-centimeter sand cushion at the bottom of the pit. Sand must be poured into separate layers, tamping each of them.
Lay sheets of roofing felt over the made pie. They will be an excellent waterproofing material for the foundation.

Creating a rubble stone foundation

After this, start laying the rubble. It must be moistened with water before starting work. Then the stones will adhere well to the cement mixture. Note! Stones cannot be placed back to back in the trench. Leave a small gap between individual pieces of rubble.

The masonry technology itself is simple. You need to remember that the short side of rubble stones is called a poke, and the long side is called a spoon. In one row of spoons should alternate when laying with a poke. The total thickness of the masonry is usually taken at 0.6–0.7 m. For a residential building, this is quite enough. Installation of stones is carried out using a small sledgehammer or a massive hammer.

The construction of a rubble foundation is carried out according to three different schemes. The operation can be performed “under the bay”, “under the scapula” and “under the bracket”. If you plan to make formwork, it is recommended to implement the “flooded” scheme. It is given below:

Place the butt row in the prepared ditch (on a sand bed). Pour fine gravel or crushed stone into the gaps. Compact the layer.
Fill the stones with liquid concrete (3 parts sand plus 1 cement).
Lay the spoon row. Repeat all the described procedures.

The topmost row is filled with thicker concrete (add less water to the mixture). The layer of mortar should have a thickness of about 0.5–0.6 m. Then, using a vibrator, compact the concrete until the mixture no longer penetrates into the gaps between the rubble stones.

Creating a foundation from rubble

Important point. If the foundation is developed according to the “bay” scheme, only light buildings (for example, a small or outbuilding) are allowed to be erected on it. Structures with a large mass are not installed on such a foundation.

For loaded houses, the foundations are usually built according to the “shovel” and “bracket” schemes. In the first case, you are allowed not to choose a bottle by size. But the “under the bracket” option involves careful selection of stones in height (it should be the same for all pieces used).

Laying according to these two options is done as follows:

Place the bonded row dry on a bed of compacted sand.
Compact the stones, pour small stones into the gaps between them.
Pour liquid concrete.
You install a row of spoons, tamp it, pour the concrete mixture.
Next, lay the bond row again, then the spoon row, and so on.

Note! It is imperative to tie the seams between all mounted rows of reinforcing bars and steel wire. You need to ensure that the rubble in the masonry does not wobble, but stands really firmly.

And one last point. When installing rubble in rows, you must constantly monitor the horizontal and vertical positions of the corners of the masonry and the surfaces of the stones themselves. Then you will have an impeccably reliable foundation.

The most popular building material today is rubble, which is made from parts of natural rocks. It can be artificial and natural. A rubble stone foundation is a strong foundation, the main component of which is rubble. Finished design 9 out of 10 parts consist of it.

These stones come in various shapes, sizes and weights, but the most commonly used stones on construction sites are tile rubble, with smooth and even sides. It is much easier to install it in any of the structures.

A rubble foundation is built similarly to brick walls - the component parts are stacked on top of each other and reinforced with concrete.

Disadvantages and advantages

The decision to lay a rubble foundation for a house should be made only after considering all the characteristics of this material, as well as weighing all the pros and cons. This is motivated by the fact that building such a foundation is not so easy. Firstly, this will take some time, secondly, it is necessary to take very careful measurements, and thirdly, the selection and distribution of stones over the foundation area is quite a troublesome task.

Rubble stone foundations are usually widely used when it is necessary to build a high load-bearing structure. And this is no coincidence; a foundation of this kind has a number of positive characteristics:

environmentally friendly material;
strength, reliability, and a guarantee of durability;
natural water resistance;
attractive appearance that does not require additional cladding.

But at the same time, there are also disadvantages to it. The most pronounced are:

quite high price of natural material;
difficulties arising during the construction of rubble structures;
high time costs;
difficult calculations that are made before construction begins.

A positive feature of a rubble foundation is the ability to combine different materials. For example, to make the structure a little cheaper, you can use rubble for the base located in the ground, and a brick on top. It should be remembered that the laying technology for these materials is different and must be adhered to.

Rules for laying rubble

Bite is mined through a special kind of explosion. To work with the foundation, you should select those elements that have two flat sides. The laying of a rubble stone foundation is carried out using a cement mortar using the “under the blade” principle. The thickness of the seam between each stone should be at least one and a half centimeters. It is not recommended to do more, since the rubble will settle and the structure itself will collapse.

Before laying, the stones must be cleaned of various types of contaminants and slightly wetted. Seams with minimal dimensions, as well as the strength of the ligation of foundation parts, will facilitate the use of fragments of different sizes.

All work on laying the rubble foundation is done by hand. The largest stones are usually located at the bottom and in the corners. Due to them, the stability of the structure is achieved. This can sometimes be very difficult, because sometimes you need to turn the bottle over more than once before you find the most best option its location.

To increase the bearing capacity of this type of foundation, a cement mixture solution is poured under the first row of stone. The area where the rubble will be missing is covered with small stones. Later they can be used as wedges.

All subsequent rows of masonry are made using a thicker mortar. Here they already use stones no more than 30 centimeters thick. All elements of the rubble foundation are laid in such a way that they are located close to each other with maximum density and the consumption of concrete is minimal. The top row of masonry should cover vertical seams bottom row.

The rubble base can be expanded by creating ledges consisting of at least two rows. The connecting parts of the future structure must be correctly “tied” with the upper masonry. And remember that in some places excessive load is unacceptable, since this may be followed by a shift of the stones and complete destruction of the laid layers.

Cladding of rubble foundation

If your house or other premises has a basement, then the foundation is made of rubble, at its location it must be covered with facing bricks. The lining work is carried out at the same time as the construction of the foundation. Every 4 or 6 rows are tied together with pokes.

As a result, you will receive a facing surface, the rows of which will completely coincide with the horizontal seam of the load-bearing structure. The brick base must have a thickness of more than 75 centimeters. And the rubble is laid in rows about 25 centimeters high. It is also necessary to fill with mortar all the voids that formed during the installation process.

Working on a rubble strip base

To make a strip foundation from rubble stone, you need to select a suitable site. Often this type of foundation for a building is used in places with complex soils that are prone to swelling. Before starting the main work, you need to explore the construction site and study the hydrogeological features of the area. You need to pay attention first of all to the level of groundwater, soil moisture, as well as the depth to which the ground freezes. And only then can you dig a trench.

You must first mark the area using a regular tape measure or wooden pegs and twine. You can dig a ditch yourself using a shovel or use an excavator to do the work.

The size of the stone blocks directly determines what the foundation will be like. The walls of the trench should be several centimeters wider than the rubble, since experts do not recommend laying stone end to end. And the depth of the ditch should be at least a meter.

With a professional approach to work, you can reduce the time required to pour the foundation by several times. There are instructions for this:

The site is marked.
Trenches are dug and formwork is installed.
A little sand is poured into the finished trench and stones are placed there, pressing them into the created “cushion”.
All gaps resulting from laying are filled with crushed stone and compacted.
Prepare a concrete mixture (1:3) and pour it into the first row to make it more durable.
Another row is laid out using the same principle. At the same time, do not forget to “bandage” the seams, as when laying brick material.
The rows that will protrude above the ground are reinforced with wire or relief reinforcement.

Some tricks in constructing a rubble base

To achieve a fairly good result, you need to know something about how to simplify your work and at the same time increase its efficiency:

In order to build a strip foundation from rubble stone, you need to prepare a cement mortar. It is almost the same as for masonry brick materials. Powder grade M 400 or M 500 is used for preparation. To prevent the concrete from cracking in the end, the sand should not contain clay particles. It also needs to be cleaned of various debris and all kinds of impurities.

Initially, you need to mix cement and sand, and then add water. The consistency of the solution should resemble sour cream.

When laying a strip base made of rubble, you can use 3 methods: pouring, “under the blade” and “under the bracket”.

The first is chosen when constructing small buildings no higher than 10 meters. The stone used is different and is not selected. On top of the laid blocks, pour crushed stone (a layer of 5-10 centimeters) and compact it well.

After the preparatory work, the rows are filled with concrete mixture. Remember that the material is initially laid dry, and only then the solution is poured. Using a vibrating compactor, it is distributed over all the voids that have arisen. These measures will greatly increase the strength and reliability of the foundation.

The other two methods are characteristically different from the first. First of all, it requires careful selection of stones. When laying them there should be minimal gaps and voids. These options are of course optimal, but require a lot of time and additional labor costs. The stone blocks are laid out horizontally, and in order to achieve absolute evenness along the entire length of the foundation, a rope is pulled. And the main aspect is the presence of rubble stones of approximately equal size.

If there is cheap "bed" in the region natural stone A do-it-yourself rubble foundation will cost much less than a monolithic or prefabricated structure made from FBS blocks. Rubble is not sorted into fractions and does not have smooth edges, so instead of cords for masonry or pouring, formwork is often used.

Rubble stone ensures a reduction in the foundation construction budget by at least one and a half times. The strength of the structure is comparable to a monolith, the main filler of which is the same material, only of smaller fractions. Basement part the house does not have to be decorated; the underground part is waterproofed by treating the seams with special compounds.

The construction of a rubble foundation is similar to masonry or concreting. In the first case, a cement-sand mortar is used with the addition of penetrating mixtures or liquid glass, which impart water-repellent properties.

There are two options for constructing a rubble foundation:

concreting with laying rubble stone;
rubble masonry.

The foundation is made using rubble masonry.

Attention! If the rubble concrete foundation is not planned to be lined in the basement, this massive structure will become a cold bridge. Heat loss through floors and ceilings will increase, since at subzero temperatures the material will freeze through.

Earthworks and foundation

At the stage of moving the full-scale axes of the house into the building area, it is necessary to take into account several factors that significantly affect the productivity and quality of work:

the size of the stone is much larger than the brick, the tape is 45 - 60 cm minimum;
It is very difficult to reinforce masonry, so sometimes plaster mesh or fine mesh Chain-link mesh are used;
even for masonry, it is better to make formwork that can be moved in height, which will sharply increase the pace of work;
The rubble material should be sorted into small and large stones before starting work.

The construction of trenches is standard, 0.5 - 0.7 m is added to the width of the tape from the inside (comfortable for rearranging the formwork, opening joints), 1.2 m from the outside (necessary for insulating the blind area, laying drains). The trench is dug to the design depth, since below the freezing mark there are guaranteed to be no heaving forces, and there is no need for an underlying layer of non-metallic material.

Attention! If you plan to pour a rubble concrete foundation, in order to avoid leakage of cement laitance into the lower drainage layer, it is necessary to make a footing 5–10 cm thick, twice the width of the tape, and fuse 2 layers of rolled waterproofing onto it.

Features of formwork design for different technologies

The technologies for rubble masonry and concreting a foundation strip using rubble stone are very similar. The differences are:

when laying, stones are laid on mortar;
When concreting, the formwork is filled to 30 cm with concrete, into which large stones are embedded.

Unlike brick, rubble has an uneven shape and it is very difficult to lay it along a thin cord. Therefore, it is easier to fix two shields along the outer and inner edges of the tape in order to lay the stones close to them.

Therefore, the formwork design for these two technologies for building a house foundation will be different:

for concreting, standard shields will be required for the entire height of the tape with a polyethylene film stretched along the inner surface so that the mixture does not flow out through the cracks and the concrete does not dehydrate upon contact with wood;
for masonry, a shield 30–50 cm high is sufficient, so that it can be conveniently moved in height as the foundation walls are built up.

Attention! It is not recommended to use slot foundation technology when the formwork is trench walls. If the soil does not crumble from its surfaces, this indicates a large percentage of clay, which is guaranteed to swell in winter and destroy the masonry. It is necessary to widen the trench, lay drains, backfill with sand, and ASG.

For secure support wall material At home, on the upper edge of the rubble foundation, it is necessary to select stones with a flat surface for the last row. Unlike classical masonry, the construction of a rubble structure is more reminiscent of concreting:

a film is laid on the underlying layer;
a bed of mortar 3–5 cm thick is applied to it;
two longitudinal rows of stones of approximately the same size are installed;
then the mortar is laid again, the bed is leveled;
ligation is performed with a butt row on the outer or inner side;
in the third row the poke is placed on the other side;
then several rows of spoons are installed (long side along the wall);
At the corners it is necessary to bandage with whole, ¾ stones.

Some experts wet the stone with water (dipping before installation without soaking). However, this material is not fired in ovens and usually has natural moisture, so the procedure is not necessary.

Attention! The consistency of the solution should ensure that the joints in the previous row are completely filled. To increase plasticity, add a Superplasticizer or a few drops (5 - 7 per concrete mixer) of Fairy type detergent.

Concreting using rubble stone

Laying the rubble concrete mortar into the formwork is a little more difficult; you will need a reinforcing bar or an internal vibrator. The crushed stone fraction in the mixture should be small (5/10 mm) for better filling. The technology looks like:

laying concrete - a 30 cm layer is poured inside the formwork without compaction;
stone distribution - the rubble is not covered, but laid out in a 20 cm layer so that the outer edges come into contact with the formwork panels;
recessing the rubble - with fittings or the tip of a deep vibrator, on which a special visor is put on.

After immersion, the stones should not stick out from the concrete. The break between laying the mixture and stones should not exceed a quarter of an hour. If it is planned to stop work, concrete or rubble runs out, the laid stone must be covered with a mixture compacted with a vibrator attachment.

Attention! The upper 30–50 cm are concreted without stone; before laying the mixture, a reinforcement cage is installed on the last row of rubble so that the upper belt of the longitudinal rods is recessed into the concrete by 2–5 cm (standard protective layer).

Waterproofing

Depending on the technology used for making the foundation of a house using rubble stone, the surface of the tape does not have the same roughness. Therefore, different methods of waterproofing the underground part are used:

rubble concrete foundation - the surface is more even, possible over a primer;
rubble masonry - the surface is uneven, plastering with moisture-resistant mixtures, coating with bitumen, polymer or epoxy mastics is used.

Attention! If penetrating compounds are introduced into the solution or concrete, waterproofing of the structure is not required.

Advantages and disadvantages

The main advantages of a rubble strip foundation for a house are traditionally:

reduction of the construction budget;
reducing work time through the use of large-format material;
high performance characteristics(weather resistance, strength).

The disadvantage of rubble masonry is the lack of reinforcement and excessive mobility of elements inside the structure. When concreting into formwork using rubble stone, there are no disadvantages at all. The tape can be qualitatively waterproofed and covered with thermal insulation. It is a monolithic structure with an upper reinforced belt, which compensates for tensile loads from possible swelling of soils.

Thus, the construction estimate country house can be completely reduced through the use of budgetary building material. It is more difficult to work with rubble stone than with brick, but the large format allows you to reduce construction time.

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The main component of a rubble foundation is rock fragments of various sizes. Individual specimens intended for construction can reach sizes up to half a meter on the largest side and weight up to 50 kg. More bulky stones cannot be used without the use of special equipment, so the average dimensions of the stones used for the construction of the foundation range from 30-50 cm.

An example of a finished rubble stone foundation

Rubble stone is widely used not only in the construction of various structures, but also as a decorative element.

They are used to decorate walls and perform other structures in landscape design.

The characteristics of rubble stone are quite varied and each of them has its own impact on its cost.

First of all, the stone is divided into types - it can be sandstone, limestone or dolomite. In addition, there are also classes of rocks:

Sedimentary, formed under the influence of the external environment;
Metamorphic, formed due to changes in the structure of minerals under the influence of pressure or temperature;
Igneous, created as a result of crystallization or solidification of magma.

But for construction, what is most important is not so much the composition and reason for the appearance of rubble stone, but rather its shape.

Existing types natural stone

There is also a classification based on the origin of the material:

The most commonly used industrial rubble is produced in crushed stone mines. Actually, the stone itself is the raw material for this material;
A rounded rubble is formed due to natural reasons, and takes on a smoothed shape due to the influence of external factors such as water or wind. Most often used in the construction of large industrial facilities due to its irregular shape;
The bedded rubble is ideal for private construction, including the construction of foundations. The main feature of this type is at least two parallel edges, which make it quite easy to lay the stone on the mortar.

The location where the stone is mined also matters, since in different areas the composition of the material has its own characteristics.

Pros and cons of a rubble foundation

The main advantage of this type of foundation is its very high strength and reliability, regardless of the rock from which it is created. In turn, this guarantees the durability of the use of such a base. Moreover, in case of poor-quality installation, if the mortar has crumbled in some places, the defect can be eliminated without any problems, and the quality of the base will not be affected.

Rocks are less susceptible than others to the influence of the external environment, including moisture, due to which the foundation, and with proper waterproofing and the house, flooding is completely harmless.

Rubble is not subject to freezing, so it is quite possible to save money on thermal insulation of the house.

In addition, the foundation, made of rubble stone, looks more than presentable even without finishing.

The process of building a rubble foundation

The rubble stone itself is an inexpensive material; the increase in cost, and a significant one, occurs due to the delivery of the material to the construction site. Therefore, in areas located near the mine, its price is low. In these areas, rubble stone is the most budget option for construction.

You will incur additional expenses during construction if you plan to hire employees. Laying rubble stone is carried out only by hand, which increases the labor intensity of the work by an order of magnitude, and, accordingly, its cost.

In what cases can a rubble stone foundation be used?

For all its attractiveness, a rubble foundation cannot be used for all types of buildings. The problem is that a rubble foundation is quite mobile compared to other types of foundation.
It is ideal for very heavy buildings of 2-3 floors, which crush it with their mass. They also stand well on it, which are quite resistant to tensile loads. But if the building has concrete or brick walls, and their weight is not enough, then such a house will not last long and will soon be covered with quite extensive cracks.

The soil on which the foundation is planned to be built also has its own requirements:

In order to determine the characteristics of the soil on the site and the location of groundwater, it makes sense to order geological surveys. Based on the results obtained, you can decide whether a rubble stone foundation is suitable for you, and also calculate its parameters, such as the depth and width of the base.

The procedure for pouring concrete into a rubble stone foundation

Production of rubble foundation

It is worth mentioning right away that strip foundations are mainly made from rubble. The fact is that creating a columnar base is a rather complex and time-consuming process, so such a base is used quite rarely.

In some cases, they are used when the soil under construction has complex characteristics. The main difficulty in making these two types of foundations is that in order to select a suitable stone, sometimes you have to sort through dozens of specimens, the weight of which is quite noticeable.

Rubble stone strip foundation

The manufacture of this type of base is very similar to, however, it has its own characteristics:

First of all, a system of trenches is broken under the foundation with a depth below the freezing depth of the soil. In this case, the width of the ditch near the bottom should be 20 cm greater than along the upper edge, that is, in cross section the trench should have a trapezoidal cross-section.

If necessary, the soil at the bottom of the pit is carefully compacted, after which sand is poured to a height of 15-20 cm.

If the soil is highly saturated with water, the first layer is laid with medium-fraction crushed stone, which will play the role of drainage system. Sand is also poured on top with mandatory pouring to create a dense base.

Often, a reinforced concrete layer of 30 cm is poured on top of the pillow for reliability.

Ready strip foundation made of rubble stone

In this case, additional waterproofing is laid between the cement and sand cushion to prevent concrete destruction.