Rubble foundation for the house. The strength of the foundation of rubble stone and its construction The foundation of rubble stone
The initial stage of construction of almost any engineering structure is the construction of a foundation. And natural stone, also known as rubble, is the best suited for the role of a reliable and environmentally friendly filler for a sand-cement mixture. Due to the irregular geometry of the material, many believe that working with a stone, the creator of which was Mother Nature, requires a certain skill and skill. In reality, this is not entirely true, and it is possible to competently equip a foundation made of rubble stone with your own hands even with the complete absence of special training: a simple desire and moral and psychological attunement to physical labor will be quite enough.
The process of starting the hand-made "sculpting" of the foundation should be preceded by the purchase of crushed stone of small fractions (it will be needed to fill the voids), the purchase of sand and cement (to form a "cushion" for the future concrete base and the possibility of preparing a working mixture), as well as the delivery of rubble stone to the object ( the latter must meet the stated criteria for strength, frost resistance and water resistance). It is also worth taking care of the presence of waterproofing material (roofing material).
Filling a solid foundation with a rubble stone, and then building a house on top of it, without having the appropriate tools at hand, is an unsolvable task. So inventory. Among other things, you will need:
- several shovels and bayonet shovels;
- durable and sufficiently capacious container for mixing the solution;
- trowels with different working surface area;
- rule-level and its water counterpart;
- construction tape measure and plumb;
- manual or mechanical rammer, heavy sledgehammer, stone hammer (pick), and chisel.
Armed with tools and having prepared all the consumables in the right amount, you can finally start looking for an answer to the question of how to make a foundation from rubble stone without involving specialists.
Technological features of building a foundation from rubble stone: installation of the lower layer
The foundation, the main filler of which is natural stone (but), is laid at a certain depth (depending on the reliability of the soil foundation). Moreover, the installation depth must necessarily exceed the maximum level of soil freezing. Direct digging of trenches is preceded by a breakdown of the area according to the development plan. Digging of the soil is carried out on the basis that the width of the excavation will make it possible to build a foundation “with a margin”, that is, the distance from the edge of the bearing walls of the future structure to the border of the concrete base will be at least 10-15 cm. ”, caused by uncontrolled shedding of soil inside the trenches. The solution to the problem can be a primitive formwork made from improvised boards or sheets of metal, which is removed immediately after the completion of the pouring process.
In dug trenches, the so-called "sand cushion" is created. This is done in several stages, with each layer of sand subjected to thorough compaction with moisture. At the final stage of "trench work", a waterproofing layer is installed on an already prepared "cushion" at the bottom of the excavation: sheets of roofing material, or its analogue, are evenly laid "overlap" (thus, unforeseen loss of moisture during the hardening of the concrete-stone belt is minimized) . It is worth noting that, having no experience in the field of installation of such structures, it is preferable to build a strip foundation from rubble stone, rather than trying to master the technique of pillar laying “with a swoop”. The second option is associated with the need to seek answers to complex questions, such as balancing a monolithic base, calculating the optimal "threshold" points, and the like.
Natural cobblestones with the most even (flat) horizontal surfaces will serve as that “support”, on which both the foundation itself and the structure (house) under construction will subsequently “sit down”. Stones with this geometry should be pressed into the sand base at the bottom of the trench, and at the same time be careful that they do not swing and are directed along the excavation, and not across. It is quite probable that in the purchased batch of buta there will be no such “suitable cobblestones” for laying in the first row of foundations at all.
You should not panic: all you have to do is arm yourself with a chisel and a pickaxe, and independently “correct the defects” of the natural material.
In the course of pressing the buta into the sandy “cushion”, small depressions and openings will certainly begin to form. To get rid of them, you have to resort to tamper again. However, this time the compaction implies the additional use of a smaller filler (crushed stone or pebbles). It looks like this: the voids between the rubble are covered with fine-grained gravel, after which these zones are methodically processed with a sledgehammer until the surface is completely leveled. And only after that, the first layer of the base is poured with a cement-sand mortar (at a ratio of 1: 3).
It is important to understand that by making a foundation of rubble stone with your own hands, you take full responsibility for compliance with building safety standards. So, for example, if the height of the same first layer at the base is not maintained, then there will be a high probability of the formation of a critical deformation of the concrete structure. (It is recommended to lay the rubble on the bottom of the trench in such a way that after the initial filling, the layer height fluctuates between 30-40 cm.)
Laying and, accordingly, pouring the second and subsequent rows of rubble foundation is carried out according to the algorithm described above. The only difference is that the seams are periodically dressed, as in standard brickwork, and the natural stone itself is mounted directly on the uncured mortar.
A separate topic is reinforcement. A high foundation needs additional stabilization with strong wire or reinforcement. As a rule, the last 3-4 layers of the structure are subjected to reinforcement. Regular tamping and staggering of the moving mass of each new level will guarantee that the construction of the rubble stone foundation will take place without technological deviations.
Practical recommendations for arranging a rubble foundation: optimizing the workflow
Professional builders have long developed algorithms for optimizing certain processes, and no one can forbid amateur beginners who, say, set out to learn from their own experience how the foundation is laid from rubble stone, to arm themselves with this knowledge. So, a few practical tips that can significantly reduce physical activity during self-assembly of a concrete base:
- the presence of gentle slopes in trenches dug for pouring a rubble foundation makes it possible to equip a comfortable working platform between the bottom of the excavation and its walls (accordingly, the supply of mortar and stone is accelerated);
- the problem of steep slopes is solved by installing wooden scaffolds;
- on the sides of narrow and shallow trenches, it is advisable to place containers for a cement-sand mortar, and in the intervals between them - pile up a quarry;
- advance “booking” of a place for openings for laying communications and ventilation reduces the time for building a foundation by several days;
- the required volume of all consumables must be calculated before pouring, so as not to violate the installation technology.
The relevance and demand for foundations based on rubble stone is largely due to their high bearing capacity and durability, but its impeccable aesthetic appearance also plays an important role in the popularization of natural material. Structures made with the use of natural cobblestone often eliminate the need for additional finishing work. In addition, the rock is very "friendly" in relation to other facing products, which, of course, plays into the hands of supporters of economical construction. And most importantly: in order to make a foundation of rubble stone yourself, you do not need to be an architect with a world name or have seven spans in your forehead! Armed with patience and following simple rules and recommendations, almost anyone is able to master the technology, the history of which dates back centuries...
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The construction of any building begins with the construction of the foundation, the strength of which determines the stability and durability of the structure. Trying to reduce the amount of estimated costs, developers use building materials of natural origin and independently build a foundation of stones. Booth is one of the most popular building materials due to its increased strength, inexpensive price, and resistance to moisture. Consider the properties of building materials and the technology for performing foundation work.
Booth is one of the most popular building materials due to its increased strength.
Foundation stone - features of natural building materials
When planning to build a stone foundation for a house, many prefer butu, due to the proximity of the quarries in which it is mined. The construction of a rubble base is similar to the construction of a brick box of a building - the rubble is laid out tightly and fixed with concrete mortar. When deciding to use rubble stone for the foundation, you should study:
- building material properties;
- types of natural stone;
- boot selection rules.
It is also important to know how to prepare the material for construction activities. Let's dwell on these issues in detail.
Advantages and weaknesses
The study of the characteristics of the material is mandatory when deciding on the construction of a stone foundation. Despite the fact that the buta stone foundation has increased strength and can be used for more than a hundred years, the advantages of natural building materials should be studied, as well as its weaknesses should be analyzed.
Natural building material has a set of advantages:
- increased margin of safety;
- increased bearing capacity;
- environmental cleanliness;
Do-it-yourself concrete foundation
- long period of use;
- resistance to moisture;
- resistance to temperature changes;
- attractive appearance;
- affordable, in comparison with other building materials, price.
Natural rubble is able to maintain integrity under the influence of forces exceeding 100 kilograms per 1 cm² of surface. This allows you to use it for the construction of the foundations of two-story buildings. However, the use of the material has weaknesses:
- significant time spent on adjusting the size of rubble stone for masonry;
- increased labor intensity of masonry work, caused by the selection of the form of building material;
- the need to preliminary perform complex calculations that determine the bearing capacity of stone foundations;
- the impossibility of using rubble stone for the construction of foundations for multi-storey buildings.
Despite the disadvantages, environmentally friendly building materials are often preferred due to their affordable price and availability.
Natural rubble is able to maintain integrity under the influence of efforts
Applied varieties of rubble stone
Professional builders call a rock of natural origin mined in quarries:
- various types of limestone, differing in structure and color;
- multi-colored granite mined in various deposits;
- calcareous tuff, as well as siliceous and volcanic rocks;
- dolomite, representing carbonate rocks of sedimentary origin.
The material has the following characteristics:
- color scheme;
- structure;
- overall dimensions;
- weight;
- form.
Natural bottle has differences in shape
The material used for laying the foundations is subject to certain requirements:
- the maximum weight should not exceed 30 kg;
- the overall dimension in the largest dimension should not be more than 50 cm.
Depending on the configuration of the building material, it is divided into the following types:
- ragged. It is easy to distinguish externally by its irregular contour and oblique edges, as well as numerous chips. This is due to the mining technology carried out by the explosive method;
- cobblestone. This type of rubble is distinguished by a rounded shape, as well as a size not exceeding 30-35 cm. Round boulders look harmoniously in rubble masonry and do not require external decoration;
- bed stone. It reaches a length of 0.5 m, has two parallel faces. This type of mineral is a part of a layered stone mass, mined by breaking out of layered rocks;
- flagstone. This type of buta is characterized by a reduced thickness compared to the length and width. The upper and lower planes of the mineral are parallel, which facilitates laying and reduces labor costs.
When choosing a stone for the foundation, its features should be taken into account.
Bedrock but “Volga” made of sandstone
Despite the fact that the booth can be found by yourself in natural conditions, it is problematic to assemble it on your own in the right amount to perform foundation work. When purchasing a stone for a foundation, it is important to be able to determine its quality. Sequencing:
- visual inspection. Cracking and delamination of the material is not allowed.
- Strength test. When struck with a hammer, the rubble stone must remain intact.
- Density estimation. As a result of hitting with a hammer, there should be a sonorous sound.
It is also important to pay attention to the cleanliness of the outer surface. The concrete mortar will not be able to contact the dirty material normally, which will affect the strength.
Preparation of building materials
When planning to build a stone foundation for a house, you must first prepare the material. To do this, split large blocks into small pieces weighing up to 25-30 kg.
Rubble stone has been used for the construction of foundations and plinths, and in some cases walls, from time immemorial. This was due to its strength, as well as its availability on a par with such building materials of natural origin as clay and wood. Booth is a synonym not only for reliability, but also for aesthetics. The article will discuss how to make a foundation of rubble stone with your own hands.
- ecological cleanliness;
- high moisture resistance;
- durability (buta constructions will last for several centuries);
- resistance to sharp temperature fluctuations, as well as resistance to vertical and horizontal loads;
- invulnerability to destruction by exposure to fungus, mold and insects;
- small financial investments, but taking into account the proximity to the stone quarry;
- beautiful appearance.
Rubble stone photo
Well, from the negative sides it should be noted:
- the difficulty of fitting stones for tighter placement;
- high time costs, including the selection of buta of the optimal shape, mixing and pouring the concrete solution.
rubble stone
- Booth is a stone with jagged edges. It can be obtained both by the natural destruction of rocks, and through blasting in quarry areas. The rock can be absolutely any: dolomite, shell rock, sandstone, etc.
- The most convenient stone for arranging the foundation and basement is flagstone. Such a material has a flat shape and has relatively flat planes of opposite sides. The bedded type of buta reduces labor costs by reducing the fit of the masonry element.
- When choosing a stone, a visual inspection should be carried out: it should not show cracks, delaminations or other defects. The quality can be determined by a strong blow with a hammer on the surface of the buta - a sonorous sound in tone, as well as the absence of any damage, indicate the strength of the material.
How to make a stone foundation
Mortar for laying rubble stone
- The solution is kneaded on cement M300, M400 or M500. With the use of such brands, the mixture will turn out to be a denser consistency. Sand must be clean with a minimum content of impurities, their presence will reduce the strength of concrete even when using high-quality Portland cement.
- For 1 part of cement, 3 parts of sand are taken. If a rubble concrete foundation is being erected, then it makes sense to add 3 parts of crushed stone of a fraction no larger than 5x20 mm. A portion of water should ensure the fluidity of the solution so that it can fill the voids between the stones.
- When mixing, it is important to respect the proportions. The mixture should not be too thick, otherwise air bubbles may form during pouring, which over time will lead to the destruction of the supporting structure. But at the same time, the mortar should not spread without residue between the masonry elements.
- For work, you can use ready-mixed concrete. However, it is supplied in concrete mixers in rather large batches, which is not very convenient. After all, it takes a lot of time to select stones of a suitable configuration, and it is highly doubtful that the equipment will wait until the next row of rubble masonry is ready.
Basic moments
- The maximum strength of the rubble strip foundation is achieved through careful selection of material and adherence to masonry technology.
- To increase adhesion between mortar and rubble, the stone is cleaned and moistened immediately before laying.
- The voids between the stones are minimized. In addition to the solution, they are additionally filled with small stones or gravel of various fractions (mainly 40x70 mm).
- The thickness of the solution layer should not exceed 15 mm, with a larger indicator, there is a possibility of subsidence of the structure with subsequent destruction.
- For the initial and final layer, a large bedded rubble with the most even planes is used. In the first case, the bottom row will serve as a reliable support for the entire masonry, and a grillage will subsequently be installed on the top row.
- When laying, dressing must be observed, as when using blocks or bricks.
- Particular attention is paid to the corners of the foundation. The material should be free of cracks and inhomogeneous inclusions, as they will be subject to a high load-bearing load.
- During work, take care in advance of all technological openings (ventilation, vents, sewers, etc.). Otherwise, after solidification, it will be very problematic to make them.
For work you will need:
- a sledgehammer, which is necessary for plinting large stones weighing up to 30 kg;
- hammer. With its help, sharp corners are chipped, as well as the sediment of the buta during the masonry process;
- shovel for mixing the solution;
- Master OK;
- building level for measuring operations;
- twine, plumb line and tape measure.
Preparation
- Before work, geological surveys are carried out, on the basis of which the type of soil is determined. It is not recommended to use rubble for a foundation built on heaving, clay, peat and sandy soils.
- First, the site is cleared: debris is removed, stumps are uprooted. For the construction of light buildings, it is enough to remove a soft layer of soil (approximately at a depth of 5-10 cm). With the help of driven pegs and stretched string, lines are marked for the future foundation.
- When preparing, it is important to pay attention to the horizontality of the relief. If the height difference is minimal, then leveling is carried out by uneven removal of the soil layer. With significant irregularities, the foundation body is adjusted to the horizon during construction, by “raising” at the necessary points.
- If you plan to build a solid house made of wood or brick, then the depth of the trench can be from 50 to 100 cm, this indicator depends more on the type of soil. The presence of weak soils implies a greater depth of the ditch. If necessary, formwork is arranged to prevent shedding of earthen walls. As for the width, it should exceed the actual width of the walls by 10-15 cm on each side, but the minimum figure is 35 cm.
- Compacted sand acts as a sealing layer, the height of the pillow should be at least 15 cm. It would be useful to have waterproofing, here you can take ordinary sheets of roofing material that overlap. This material prevents leakage of moisture from the poured concrete mixture.
Rubble stone laying
- Rubble material is laid in rows of the same height, while it is allowed to have a large stone overlapping 2 rows in height in the masonry. The work is carried out according to the principle of brickwork, that is, dressing must be observed. Of course, the ideal cannot be achieved, but, nevertheless, the width and height of the stones must be selected with great care.
- It is allowed to lay the bottle alternately with the short and long side (poke and spoon). Then, subsequently, spoon rows are laid on the rows of rows and vice versa. If necessary, the voids formed due to the irregular shapes of the stones are filled with gravel. Pebbles can be used as a kind of wedges, they are knocked out with a hammer at the right point.
- The laying of each row begins with the installation of lighthouse and corner stones, which will set the height of the entire strip. They are stretched with twine, which serves as a guide and observance of straightness during masonry work.
- The bottom row is made of bedded buta. Large and relatively flat stones are laid dry. The flattest side should be facing down. The voids are filled with gravel or broken stones.
- Fitting stones for a stable position in the masonry is first done dry, taking into account the standard row height (25-30 cm). After pinning, the bottle rises and part of the solution is supplied. The material is seated in place with a sledgehammer or hammer. There should be enough sand-cement mixture so that when pressed on the material, it can also fill vertical seams. Thus, the foundation will gradually acquire the desired height.
- It is possible to make the foundation more durable and reliable by means of a “stepped” design. For this, the trench is made 2 times wider than the bearing wall. Rubble stone is laid according to the previous technology. The difference lies in the gradual narrowing of the bearing base. Concessions are made at least every 2 rows. Two or three steps are enough to increase the bearing capacity several times.
- Masonry work is necessarily accompanied by regular measurements of horizontality and verticality by means of a level or laser. While the solution has not hardened, the location of individual elements is adjusted.
- At the end of the work, waterproofing of the upper part of the foundation is carried out and a blind area is constructed, which will protect the structure from the adverse effects of rain, dew and melt water flowing from the roof. It is mandatory to equip a drainage system that will ensure the removal of excess moisture from the structure.
Rubble concrete masonry
- This technology allows you to significantly reduce both the time and effort for the construction of the foundation. It should be noted that the "for pouring" method is suitable only for non-sagging soils, under buildings erected no higher than 2 floors. It is better to build a foundation in one breath, that is, without interruptions.
- The depth of the trench in this case must be increased with the calculation of laying a sand cushion (10-15 cm) and a layer of crushed stone of a fraction of 20x40 mm (10-15 cm) on the bottom. Be sure to perform fixed formwork, the walls of which must be carefully strengthened and provided with spacers, especially in the corners.
- This technology allows additional use of broken bricks, gravel and crushed stone of a large fraction. A distance of approximately 5 cm is left between the stones and the walls of the formwork. This is necessary so that the material is covered by the concrete mixture, forming a monolithic structure.
- Despite the simplicity of the process, it is impossible to throw stones into a trench and then fill it with a sand-cement mixture. A chaotic arrangement will reduce the strength of the structure, and hence its bearing capacity.
- As in conventional masonry, but is used only in a clean and moistened form. A layer of mortar is poured onto the bottom of the trench, after it dries, bedding material is laid out, forming an almost even and stable base. The bottom layer is covered with a sand-cement mixture, into which the next row of stones is pressed. The material to be laid must “drown” at least 2/3 of its height.
- Ideally, each layer is treated with vibratory equipment. Pressing allows not only to compact the bottle, but also to prevent the formation of air bubbles. If it is not possible to apply the technique, then the work is done manually. To do this, the largest stones are slightly lifted with a bayonet shovel or crowbar. Each row is laid with wire, metal rods or reinforcing mesh.
- Although this method involves the use of stones of arbitrary shape, their width (diagonal) should not be more than 2/3 of the width of the structure under construction.
- If for some reason it is necessary to interrupt construction work, it is recommended to fill only vertical joints with mortar. When pouring the entire row after the resumption of work, large notches are made in the frozen mass, fragments and dust should be removed.
Rubble stone foundation video
- The masonry is covered with wooden flooring or any roll materials to protect against premature drying. This method is especially relevant in windy or sunny weather. If possible, the first few days of the unfinished foundation are moistened with water.
First of all, when building a house, you need to decide on the foundation. Decide what type and what material it will be, what type of insulation and waterproofing to apply.
If we talk about the material, then the choice will be represented by concrete, rubble and rubble concrete options, and asbestos-cement pipes are also used for the foundation. Most often, rubble is used to build a private house.
What is a rubble and rubble foundation
Booth or rubble stone are stones obtained as a result of the development of such rocks as limestone, sandstone, dolomite. It is either stones of various shapes with irregular angles and irregular shapes, or stones with even edges - platy or bedded.
A rubble foundation, often of a strip type, is a masonry in which an incomparably small amount of auxiliary materials (liquid mortar on clay, lime or cement) is required for its execution. Priority can be given to bedded butu and a stone of the correct form. Firstly, they are obviously more convenient when laying - even edges and corners are much easier to lay closer to each other, and secondly, the strength of laying from bedded and regular stone is 1.5 and 3.5 times higher than from chipped stone, respectively.
What you need to know when choosing a foundation
Cons of rubble foundation:
- the construction process itself is very long, laborious and expensive;
- it is difficult to provide construction "with your own hands";
- long preparation for construction.
The rubble foundation has such advantages as:
- does not require protection from moisture and decorative processing;
- strength and long service life;
- resistant to water and frost;
- but material of natural origin.
From the above, we can conclude that the rubble foundation is suitable for a rather large private house, requiring increased strength from it, and also designed for a very long service life. But also a strip foundation made of rubble can be used for a variety of small buildings, from a cottage to a bathhouse.
Foundation on your own
For a country house, a strip foundation made of rubble is perfect. It is possible to build a columnar one, but it is much more difficult than the first one.
The first step is to determine the volume of the material. The size of the foundation in height is calculated based on the fact that it should be buried 20 cm below the freezing depth and at least 30 cm above ground level. The width of the base should be 20-30 cm more than the width of the wall. Having calculated the volume of material, it is better to purchase it with a small margin. You will need sand for a pillow under the foundation, you can calculate the volume, knowing that the thickness of the pillow will be about 20 cm. Next, you need to select and prepare the material, if the latter requires it in size or shape. Cement for a liquid solution is selected grade not lower than M100. The rubble stone for the foundation must not only be clean and without cracks, but also not exceed 30 kg. The larger one is cut to the desired size. This process is called plinting, sometimes after it a trick is made - a change in the shape of the stones closer to the parallelepiped. Immediately before laying, the stones must be cleaned of dirt and wetted.
A trench is dug for laying a rubble strip foundation, its depth is determined based on the fact that the foundation must be at least 20 cm lower than the freezing depth. A layer of sand about 15-20 cm thick is poured onto the bottom of the trench and carefully compacted. It should be noted that in heaving soils, first of all, gravel is also poured, and then sand. After the formwork is arranged. Next, the roofing material is laid, this is done with an overlap. When constructing a strip foundation, laying "under the bay" is used at a distance from the formwork or trench walls, if the formwork was not arranged. The first layer of stones is arranged from the largest and most even stones. This row is laid along the base, compacted, filled with crushed stone and poured with liquid cement mortar. The next row is laid across the trench, the next along, and so on, the laying direction alternates.
Having considered the process of building this foundation, you can be sure that it is really long and quite expensive, if hired workers are involved, with self-construction, the price of construction will be lower, although this work will take a lot of time and effort. If there are any, the result will be durable, strong, resistant to water and frost, and beautiful.
WITH weapons made of "wild" stone or buta, one of the most economical in terms of cost of constructive materials. In addition, the same do-it-yourself rubble stone foundation much easier to do than, for example, . Equipment may be needed except for earthworks.
Rubble stone is the oldest building material, actively used in construction to this day. They use but for the construction of artificial foundations in road construction, for, and how to make a rubble concrete foundation can be read in any building guide.
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What is rubble stone
Booth, "savage", "wild stone", "rock" - as soon as it is not called at a construction site, in most cases it is mined in a quarry, blowing up or otherwise crushing rocks.
Rubble stone is rarely transported over long distances, I use it mainly near the place of extraction. In the estimated norms, it passes under the section "local building materials" and at a price cheaper than the same rubble.
The choice of rocks for rubble stone depends on the region of extraction. Both metamorphic or igneous and sedimentary rocks are used, from granites and basalts, to marble or chalk.
The sizes of stones do not exceed 500 mm, weight 45-50 kg. The shape of the stones depends on the breed of their component, and partly on the method of extraction. Lamellar stones are obtained from layered sedimentary rocks, rocks that do not have a pronounced structure also give a stone of an arbitrary shape, smooth rounded stone is mined in riverbeds.
Whether this type of stone is suitable as a material from which a rubble foundation can be made depends on its properties studied in the construction laboratory.
Constructions of rubble foundations
Structurally, rubble foundations are not much different from their counterparts made of monolithic concrete. The foundation of rubble concrete, the foundation of buta can be either, have the same width over the entire height or be stepped. However, unlike reinforced concrete foundations, whose structures can work in bending, rubble and rubble concrete foundations perceive only compressive loads.
The problem of how to make a rubble foundation so that bending forces do not destroy it is solved by adding a reinforced concrete component to the rubble masonry.
For example, a reinforced concrete belt is arranged over the rubble masonry. Or they perform a reinforced monolithic support pad, on which they then build a rubble foundation with their own hands.