Concrete foundations Any building or structure must be protected as much as possible from moisture. Unfortunately, some builders neglect this type of work out of a desire to reduce the overall cost. construction work. But in vain!
The fact is that concrete perfectly absorbs water, which rises through its capillaries, and during the period when the outside air temperature passes through zero, it first freezes and then thaws, which entails cracking and further destruction of the concrete. Thus, without proper protection, the foundation of the house may crack in just a few years, which will entail the need overhaul the entire building. In addition, through cracks in the foundation, moisture, insects and microorganisms begin to enter the house, which do not bring anything good for building structures, and indeed for the owners.
What methods can be used to protect the foundation?
First, installing special flashings for the foundation. Their purpose is to drain rainwater and melt water falling onto the foundation from the roof. They are installed in such a way that the connection to the wall is as tight as possible. If this cannot be done, then it is necessary to fill the junction of the ebb and flow with sealant.
Secondly, waterproofing the foundation from groundwater. All foundation surfaces in contact with the ground are subject to waterproofing. Execution methods depend on design features foundation and groundwater level.
In the event that the water does not rise higher than one meter to the base of the foundation, then it is quite sufficient to carry out waterproofing using roofing material, which is laid before pouring concrete on the bottom and with internal sides for the formwork of the future foundation. This method is applicable not only for strip foundations, but also for drilled foundations. Roofing material is placed at the bottom of the hole drilled for the pile, and to protect the pile along the circumference, it is rolled up into a “tube” and inserted into the hole before pouring concrete.
Of course, this is the cheapest option, which is not entirely suitable if the groundwater comes too high to the base of the foundation, especially if it is flooded during floods. In this case, it is necessary to use more expensive modern materials: penetrating waterproofing or liquid rubber.
Thirdly, the foundation must be protected from surface waters, which fall on the non-buried part of it during rain and melting snow. This is only necessary if no work will be carried out on the base part of the foundation. facing works, with the exception of cladding with panels: moisture may well get into the space between them and the foundation with destructive consequences. There is no need to waterproof the base part even if it is plastered with special base plaster and then painted.
To waterproof the base, the coating method is used. The most popular in this case is bitumen mastic. There are several ways to use it. If the surface of the foundation is without cracks, irregularities and bulges, then the mastic is heated to 30 - 40 degrees and applied with a brush or roller. You can heat it with a burner or blowtorch. You can dilute the mastic with white spirit, but you shouldn’t get carried away with it - when you add it, the mastic cools quickly and, as a result, it will be difficult to mix it into a homogeneous mass.
Before applying mastic, the surface must be cleaned of dirt and degreased. If there are unevenness on the foundation, then it is necessary to knock them down. Cracks and deep depressions in the foundation can be repaired with the same mastic, but without heating it. In this case, it is applied with a spatula, similar to putty.
When waterproofing the foundation, it is necessary to take into account that any building materials fit very poorly on it. Waterproofing the basement part of the foundation must be done after the blind area is ready, which in turn also serves as a drainage system for water from the foundation.
Thus, the sequence of work on waterproofing the foundation should be as follows: waterproof the soil part, fill the blind area, perform waterproofing (or Finishing work) basement part.
When constructing the foundation for wooden house, Special attention It is worth paying attention to its waterproofing. The quality, strength and durability of the foundation will depend on it. Leaks concrete mixture at the flooding stage, groundwater can cause great damage, from constant dampness in the house to subsidence of the building and cracks in load-bearing walls. Therefore, such a process as waterproofing the foundation with your own hands should be approached correctly and responsibly. After all, this is the basis for insulating the foundation.
General rules
- Whatever waterproofing method you choose, you need to take into account several operational points:
- It is necessary to determine the groundwater level (the type of waterproofing will directly depend on this).
- Take into account the possibility of flooding in the event of heavy rainfall and floods (this is especially true for loose soils).
- The force of “swelling” of the soil during periods of frost (water, during the process of freezing/thawing, constantly changes its structure and expands/contracts, leading to both loosening and lifting of the soil, and has a destructive effect on the foundation)
- The conditions under which the building will be operated (if this is a future warehouse, then the waterproofing conditions are correspondingly higher).
There are only two types of foundation waterproofing - horizontal and vertical.
Advice: at the foundation construction stage, you should not skimp on the so-called “sand cushion”. It is not only necessary to reduce concrete leakage, but is also protected against erosion of the foundation. Moisture protection is also necessary to protect the floor of the house from moisture.
Horizontal waterproofing
It is carried out at the stage of constructing the foundation for a wooden house and will require Extra time(12-17 days) at the stage preparatory work. The drainage system also refers to horizontal waterproofing and is used when the groundwater level is high.
Strip foundation waterproofing scheme
This option is best suited for waterproofing the foundation belt type for a log house and a monolithic slab foundation.
Preparation and styling
Clay is poured into the bottom of the pit dug for the foundation and carefully compacted; the laying layer should be around 20-30 cm (you can use a “sand cushion” instead of clay). On top of the clay it is done concrete screed 5-8 cm. After the concrete has hardened (10-12 days), it is carefully treated with bitumen mastic and the first layer of roofing material is laid. Then the process is repeated again, treatment with mastic - laying roofing felt. Another concrete screed (5-8cm) is made on the second layer of roofing felt.
After the concrete has hardened, the main process of constructing the foundation is carried out, which can be additionally insulated in various vertical ways.
Also, do not forget about waterproofing the top of the foundation, because the first crown of the log house will be laid on it wooden house, which can lead to rotting of the base of the log house.
Installation of a drainage system during foundation waterproofing to lower the groundwater level
When performing the procedure as: DIY foundation waterproofing may need to be applied drainage system. It is necessary if the depth of the foundation is lower than or equal to the flow of groundwater or if the permeability of the soil is poor and the water does not go into the soil itself and begins to accumulate.
How does it work
A small trench is dug along the perimeter of the building at a distance of at least 70-100cm. The depth of the trench should be 20-25 cm below the foundation pouring level, the width should be 20-30 cm. The trench should have a slight slope towards the well collecting water.
The edges of the geotextile are laid on the bottom, which is wrapped on the walls of the trench by 60-70 cm. Next, the trench is filled with a 5cm layer of gravel, on which a special drainage pipe is laid with a slope of 5mm/1m of pipe (Tip: the desired slope can be achieved by adding gravel). Another 20-25 cm layer of gravel is poured over the pipe and all this is wrapped in the protruding edges of geotextile and sprinkled with earth.
This design allows moisture to reach the drain pipe and prevents it from clogging. The pipes, in turn, drain water into a special water collector (the dimensions of the pit or well are calculated individually depending on the influx of water).
Vertical waterproofing
Vertical waterproofing means treating the walls of the foundation itself directly. It contains many ways to protect the foundation (will be discussed below) and is possible both at the construction stage and after the construction of the building.
Do-it-yourself methods for vertical waterproofing a foundation
The essence is to completely treat the foundation with bitumen (mastic), which, penetrating into cracks and gaps, prevents moisture from entering the building.
The process is very simple, having purchased bitumen in the form of a bar on the market, you need to heat it in a container until it becomes liquid. Next, apply the bitumen in several layers to the foundation (2-4 layers will be enough), remember: do not let the bitumen cool in the container, otherwise when it is reheated to a liquid state, it will lose some of its properties.
Advice: it is worth adding a little oil waste to hot bitumen.
As an option, you can purchase ready-made mastic with increased moisture-resistant qualities. This mastic generally does not need to be heated and the number of applied layers is reduced to two.
strip foundation treated with bitumen
- Simplicity, easy to do without outside help.
- Availability.
- Price.
- Speed. The need to apply multiple layers is time consuming.
- Fragility. After 5-10 years (depending on the mastic), re-treatment of the foundation is necessary.
- Mediocre water resistance. Even high-quality treatment will not provide complete protection from moisture.
Waterproofing using roll method (roofing felt)
This method can be used either independently or as additional protection for bitumen insulation.
It is customary to take roofing felt (technoelast and isoelast) as a basis. The process itself is similar to covering a roof. From the beginning, the surface of the foundation is covered with mastic (the continuous application of bitumen is not so important here). Afterwards, the roofing material is heated using a gasoline burner and presses against the bitumen-treated foundation. The joints of the roofing material are overlapped (10-15 cm) on each other and processed with a burner.
Tip: if there is no access to the burner, you can use a special mastic with adhesive capabilities, although this option is less reliable.
Heat treatment of roofing felt
- Availability.
- Price.
- Good durability (up to 50 years).
- It is impossible to cope with this work alone.
- When using roofing felt, the most reliable water resistance is achieved. The use of more expensive materials, but this requires additional, more thorough treatment with mastic (this negates the plus in price).
Plaster waterproofing
The method is quite simple and serves both as a waterproofing for the foundation and as a way to level it.
IN plaster mixture Water-resistant components are added and it is applied with a spatula to the foundation. In order for the mixture to stick to the foundation, a putty mesh is attached to it using dowels.
Treatment of concrete with plaster
- Price of materials.
- Simplicity and high speed of work.
- Low hydraulic stability.
- Possibility of cracks.
- Short life (up to 15 years).
Liquid rubber is sprayed onto the foundation, providing excellent waterproofing. If you are waterproofing the foundation with your own hands, then the same type of liquid rubber (“Elastomix” and “Elastopaz”) will do.
Before application, the surface of the foundation is treated with a primer. Then you need to decide on the type of tire.
- "Elastomix" - applied to the foundation in one layer and hardens within two hours. Once opened, the container containing Elastomix cannot be stored further.
- "Elastopaz" - the price is slightly lower than for "Elastomix", but it is applied in two layers. After use, the remaining mixture must be stored.
Rubber is applied using a brush or roller; if possible, use a sprayer, this will significantly speed up the process.
Average consumption liquid rubber is 3kg/1m2.
Application of liquid rubber
- Excellent waterproofing.
- Durability.
- Does not require special skills.
- Relatively expensive tires.
- Without a sprayer the process is quite long.
- It is not possible to get liquid rubber everywhere.
Penetrating waterproofing
After cleaning it from dust and wetting it with water, a special solution (“Aquatro”, “Penetron”, etc.) is applied to the foundation using a sprayer, which penetrates 10-15 cm into the structure of the foundation. The solution must be applied several times.
Spraying a solution in a protective suit
- Effective waterproofing.
- Durability.
- Easy to apply.
- Possibility of use in processing from the inside of a building (processing the basement)
- Price.
- Low prevalence of the mixture.
Clay castle
Quite simple and reliable way hold back moisture. A trench about 50-60 cm deep is dug around the foundation, the bottom of which is covered with a layer (5 cm) of crushed stone or gravel. Next, the clay is laid and compacted in several stages. Clay serves as a buffer against water and does not allow it to pass under the building.
Almost the only advantage of this foundation is its simplicity. This method can be used for small outbuildings and wells. For a residential building, it can only be used as an addition to the existing waterproofing.
Screen waterproofing
Screen waterproofing option using slabs
One of the new ways to protect the foundation is to nail mats filled with clay to the foundation using dowels or a construction gun. The mats should be laid with an overlap of 10-15cm. Sometimes, instead of mats with clay, you can find clay concrete panels on the market, but their joints will require additional processing. In fact, it is a modern analogue clay castle.
Like the previous type of foundation waterproofing, this method is considered only for non-residential buildings. Or combined with other waterproofing options.
Video waterproofing the foundation with roofing felt:
Which type is better to choose for a particular foundation?
Waterproofing monolithic slab foundation may contain combined system vertical and horizontal protection from moisture. But if during the construction phase the opportunity was stifled horizontal insulation, then roll-bitumen waterproofing or insulation using liquid rubber is best suited. They are more preferable due to good penetration into possible gaps between the foundation slabs.
When waterproofing a strip foundation, preference should be given to bitumen, penetrating or plaster waterproofing.
Waterproofing of pile-screw and columnar foundation or, in addition to the proposed methods, it may require additional treatment of the metal parts of the foundation with an anti-corrosion solution. Although each foundation should be approached individually.
- A combination of different methods can be very useful.
- You should not skimp on waterproofing material; remember, the stingy pays twice.
- Before choosing the type of foundation, if you are unsure, it is better to consult a specialist.
- It is worth thinking about what type of waterproofing method will be used even at the stage of pouring the foundation (this will reduce further costs and simplify the process).
- When using the bitumen method, you can do without caulking small cracks; the bitumen itself will perfectly penetrate and seal them.
- If necessary, using the roll method, you can apply several layers of roofing felt, one on one, and do not forget to make a bitumen layer between them.
The foundation is a reliable and durable basis for any structure. Concrete, being its main component, can simultaneously be a durable, strong and fragile material. It is water and humidity that affect the basic indicators of concrete.
The use of mastic plays an important role in this case, so that the foundation of the house is truly a reliable, solid foundation. Treating the foundation with bitumen mastic waterproofs the concrete, thereby extending its service life, maintaining all specifications.
The advantages of using this material make it an indispensable product when waterproofing the base of a building. 
The advantages of its use include:
- High adhesion rate to any type of surface;
- Possibility of creating an elastic and seamless layer;
- Affordable price;
- Ability to perform work in any weather;
- Uniformity and stability of the composition;
- Increased resistance to influence various conditions environment;
- Possesses antiseptic qualities.
The advantages of treating the foundation with bitumen mastic also include its practicality, reliability, environmental friendliness, frost resistance, heat resistance, durability of the coating (up to 30 years), and ease of application to any surface.
Results of use
The use of this technology for waterproofing the base guarantees a positive result. 
Namely:
- Reliable protection from the influence of moisture of the entire structure of the building;
- Prevention of corrosion;
- Extending the service life of all building elements;
- Maintaining the functionality of building elements.
This type of waterproofing material is one of the oldest but most reliable methods of protection. These indicators confirm the need to treat any base with mastic.
Types of mastics
Mastic is a homogeneous organic mass containing modifiers, solvent, bitumen (a by-product of oil distillation), and an antiseptic. Depending on the method of preparation, two types are used for the base: cold and hot. 
Hot - cooked directly on construction site two hours before use. When preparing it, you must observe personal safety precautions. Most often, this type is used in the construction of large objects, since its cost is much lower than cold.
Cold appearance - does not require use during cooking high temperature. It is commercially available ready-made, so it is much easier to use and safer than hot. The only drawback is the high price.
Preparation for processing
When carrying out waterproofing work, you need to prepare special tools. 
Namely:
- Bulgarian;
- Construction hair dryer;
- Cement mortar;
- Primer;
- Putty knife;
- Roller or brush.
You can start coating only on a properly prepared base surface. It is necessary to carefully inspect its surface, and if bubbles, cracks or chips are detected, they must be rubbed with a fine-grained cement solution.
If such work has not been carried out, the applied layer of material will burst after some time. As a result, the quality of waterproofing will deteriorate sharply, and the work will have to be done again. The presence of “ridges” with sharp protrusions on the base is also unacceptable. They must be removed with a grinder. 
The corners of the base are being processed. They are slightly cut off or rounded. Transitions to the vertical surface are arranged with “dumbbells” to make the connection of elements smoother.
Don't forget to remove debris and dirt. Then it is necessary to reduce the humidity of the treated surface. A hair dryer is used for this. If the surface is not dried well enough, the applied mastic may swell or peel off completely.
Important! To be completely sure that the base is sufficiently dry, you can conduct a small test. Cover part of the base with film for a day. If at the end of this time condensation does not form on it, then the foundation is well dried. You can start processing it.
Primer treatment
To reduce the consumption of mastic and improve the quality of its connection to the surface, it is necessary to prime the entire base. Priming with a primer is carried out taking into account the type of mastic chosen. 
The primer is applied with a roller (brush) over the entire surface of the base. When coating the foundation with it, it will be possible to apply only 1 layer. After completing application, leave the primer to dry for several hours.
Application of its second layer is possible only at the points of connection to the base of the building structure.
Mastic application process
Treatment of the foundation with bitumen mastic begins with the surface where the water pressure is greatest (on its outer side). After opening the can, the material is thoroughly mixed. To apply it, depending on the consistency, use a spatula, roller, or brush. 
When applying it, it is important to remember that the layers must have the same thickness, be continuous, have no breaks, and the coating itself is carried out from top to bottom. The next application must be carried out after the previous one has dried.
The coating thickness is on average from 2mm to 4mm. This value is affected by the depth of the foundation. If it is located at a depth of up to 2 meters, then the layer of applied material is 2 mm. If the depth of occurrence exceeds this value, then the thickness of the coating increases to 4 mm.
It is easy to determine the readiness of the surface for applying the next layer of coating. It is enough to touch the first layer. If there is no sticking to your fingers, then you can safely apply the next layer. To extend the service life of the mastic, after completing the application of the last layer, soft soil is poured onto it.
Useful video:
If the technology of waterproofing with bitumen mastic is followed and its type is correctly selected, the process of treating the base of the building can be done independently with high quality.
Foundation waterproofing in modern low-rise construction is an almost integral part of the zero-cycle construction process. This is due to the presence of moisture in the soil in the vast majority of territories of our country. Water itself is not particularly dangerous for concrete; on the contrary, in a slightly moistened state, concrete continues to gain strength over many years. However, there are three big “BUTs”.
Firstly, concrete has the property of capillarity. This is the rise of water up through the smallest pores located inside the material. The simplest example of this phenomenon is wetting a piece of sugar slightly lowered into a glass of tea. In construction, the capillary rise of water leads (unless, of course, waterproofing is done) to the penetration of moisture, first from the outer layers of concrete to the inner ones, and then from the foundation to the walls that stand on it. And damp walls mean increased heat loss, the appearance of fungi and mold, and damage to interior finishing materials.
Secondly, a modern foundation is still not concrete. This is reinforced concrete, i.e. it contains reinforcement, which upon contact with moisture begins to corrode. In this case, the iron in the reinforcement turns into iron hydroxide (into rust), increasing in volume by almost 3 times. This leads to the formation of strong internal pressure, which, when reaching a certain limit, also destroys the concrete from the inside.
Thirdly, we do not live in the tropics, and subzero temperatures for our climate in winter period- this is the norm. As everyone knows, when water freezes it turns into ice, increasing in volume. And if this water is deep in the concrete, the resulting ice crystals begin to destroy the foundation from the inside.
In addition to the above, there is another danger. There are often cases when groundwater in a site contains chemical elements (salts, sulfates, acids...) that have an aggressive effect on concrete. In this case, the so-called “concrete corrosion” occurs, leading to its gradual destruction.
High-quality waterproofing of the foundation allows you to prevent all these negative processes. And how it can be accomplished will be discussed in this article.
By by and large You can protect the foundation from moisture in two ways:
1) when pouring, use the so-called bridge concrete with high coefficient water resistance (different grades of concrete and their characteristics will be discussed in a separate article);
2) cover the foundation with a layer of some waterproofing material.
Ordinary developers most often now follow the second path. What is this connected with? At first glance, it would seem that it could be simpler - I ordered waterproof concrete from the factory, poured it and that’s it, sit back and be happy. But in reality, not everything is so easy, because:
- the increase in the price of a concrete mixture with an increase in the coefficient of water resistance can reach 30% or more;
- not every plant (especially a small one) can produce a grade of concrete with the required water resistance coefficient, and attempts to produce such concrete on your own can lead to unpredictable consequences;
- and most importantly, there are problems with the delivery and placement of such concrete (it has very low mobility and sets quite quickly, which in most cases limits the possibilities of its use).
Application waterproofing coating accessible to everyone and with certain skills you can even do it yourself.
Materials for foundation waterproofing.
All materials used to protect foundations from moisture can be divided into the following groups:
- coating;
- sprayed;
- roll;
- penetrating;
- plastering;
- screen waterproofing.
Let's take a closer look at each of them.
I) Coating waterproofing is a bitumen-based material that is applied to the surface (often in 2-3 layers) using a brush, roller or spatula. Such coatings are usually called bitumen mastics. You can make them yourself or purchase them ready-made, poured into buckets.
Recipe for homemade bitumen mastic: buy a bitumen briquette, split it into small pieces (the smaller the smaller, the faster it will melt), pour into metal container and put on fire until completely melted. Then remove the bucket from the heat and add waste oil, or better yet, diesel fuel (20-30% of the volume of mastic), and mix everything thoroughly with a wooden stick. How this is done is shown in the following video:
Ready-made bitumen mastic is sold in buckets. Before use, for more convenient application, it is usually mixed with the addition of some solvent, for example, solvent, white spirit, etc. This is always indicated in the instructions on the label. There are several manufacturers of such mastics with at different prices and various characteristics of the finished coating. The main thing when buying them is not to make a mistake and not take material, for example, for roofing coverings or something else.
Before applying bitumen mastic, it is recommended to clean the concrete surface from dirt and prime it. The primer is made with a special composition, the so-called bitumen primer. It is also sold in stores and has a thinner consistency than mastic. Coating waterproofing is applied in several layers, each of which after the previous one has hardened. The total thickness of the coating reaches 5 mm.
This technology is one of the cheapest compared to those described below. But it also has its drawbacks, such as the short durability of the coating (especially when prepared independently), the long duration of the work and high labor costs. The process of applying mastic with a brush is shown in the following video:
II) Sprayed waterproofing or the so-called “liquid rubber” is a bitumen-latex emulsion that can be applied to the foundation using a special sprayer. This technology is more progressive than the previous one, because allows you to perform work with better quality and in a fairly short period of time. Unfortunately, mechanization of work significantly affects its cost.
The characteristics of liquid rubber and the process of its spraying are shown in the following video:
III) Roll waterproofing It is a modified bitumen or polymer material, previously applied to any base. The simplest example is the well-known roofing material with paper base. In production more than modern materials Fiberglass, fiberglass, and polyester are used as a base.
Such materials are more expensive, but also much higher quality and durable. There are two ways to work with roll waterproofing - gluing and fusing. Gluing is carried out on a surface previously primed with a bitumen primer using various bitumen mastics. Fusing is carried out by heating the material with gas or gasoline burner and its subsequent gluing. How this is done is shown in the following video:
The use of rolled materials significantly increases the durability of foundation waterproofing compared, for example, with coating materials. They are also quite affordable. The disadvantages include the difficulty of performing the work. It is quite difficult for an inexperienced person to do everything efficiently. You also can't do the job alone.
The appearance of self-adhesive materials on the market several years ago made it much easier to work with roll waterproofing. How to protect the foundation with their help is shown in the following video:
IV) Penetrating waterproofing- this is a coating of concrete with special compounds that penetrate 10-20 cm into its thickness through the pores and crystallize inside, thereby clogging the passages for moisture. In addition, the frost resistance of concrete and its protection from chemically aggressive groundwater increases.
These compounds (Penetron, Hydrotex, Aquatron, etc.) are quite expensive and have not found wide application for complete waterproofing of the foundation in a circle. They are more often used to eliminate leaks in already built and operated basements from the inside, when it is no longer possible to repair the waterproofing from the outside using other methods.
Learn more about the properties of penetrating materials and their correct use says in the following video:
V) Plaster waterproofing by and large, it is a type of coating insulation, only here it is not used bituminous materials, but special dry mixtures with the addition of waterproof components. Prepared plasters are applied with a spatula, trowel or brush. For greater strength and to prevent cracks, a plaster mesh can be used.
The advantage of this technology is the simplicity and speed of application of materials. The downside is the low durability of the waterproofing layer and lower water resistance compared to the materials described above. The use of waterproofing plasters is more appropriate for leveling the surfaces of foundations or, for example, for sealing seams in foundations made of FBS blocks, before subsequently covering them with bitumen or roll waterproofing.
VI) Screen waterproofing - this is sometimes called the protection of foundations from moisture using special swelling bentonite mats. This technology, which is essentially a replacement for the traditional clay castle, appeared relatively recently. The mats are attached to the foundation with dowels overlapping each other. More details about what this material is and its properties are discussed in the following video:
How to choose waterproofing for the foundation?
As you can see, there is currently great amount all kinds of waterproofing materials to protect foundations. How not to get confused in this variety and choose exactly what is suitable for your specific conditions?
First, let's look at what you need to pay attention to when choosing waterproofing:
- presence or absence of a basement;
- ground water level;
- type of foundation and method of its construction
The different combination of these three factors determines which waterproofing should be preferred in this case. Let's look at the most common options:
1) Columnar foundations.
can only be protected with roll waterproofing. To do this, cylinders of the required diameter are first rolled out of it, fixed with tape, lowered into drilled wells, reinforcement cages are installed and concrete is poured.
Most cheap option- use of ordinary roofing felt. If it is with sprinkles, it is better to roll it with the smooth side out so that in winter, when it freezes, less soil will stick to it. It is advisable to ensure that the thickness of the waterproofing along the entire circumference is at least two layers.
When used for columnar foundation asbestos or metal pipes, they can first be coated with any coating bitumen waterproofing in at least 2 layers.
If you are going to build on pillars, before pouring it, for greater reliability, the tops of the pillars also need to be covered coating waterproofing(even better not like in the picture below, but straight from the ground). This will prevent possible capillary rise of water from the soil into the grillage.
2) Shallow strip foundations(MZLF).
inherently must always be above the groundwater level. Therefore, for its waterproofing, ordinary roofing material and bitumen mastic are quite enough to prevent capillary suction of moisture from the soil.
The figure shows one of the working options. Before installing the formwork, a folded roofing material with a small outlet is spread on the sand cushion. Then after pouring and setting the concrete, side surfaces the tapes are covered with coating waterproofing. Above the level of the blind area, regardless of what kind of base you have (concrete or brick as in the figure), cut-off waterproofing is done by gluing on bitumen mastic 2 layers of roofing felt.
3) Recessed strip foundations (house without a basement).
Waterproofing of a buried strip foundation, regardless of whether it is monolithic or made of FBS blocks, when the house does not have a basement, can be done according to the scheme shown above for MZLF, i.e. the bottom is rolled material, and the side surfaces are covered with coating insulation.
The only exception is the option when the foundation is not poured into the formwork, but directly into a dug trench (as you understand, coating cannot be done). In this case, before installing reinforcement cage and pouring concrete, the walls and bottom of the trenches are covered with rolled waterproofing with gluing or fusing joints. The work is certainly not very convenient (especially in a narrow trench), but there is nowhere to go. This was discussed in the article.
Also, do not forget about the layer of cut-off waterproofing above the level of the blind area.
4) Recessed strip foundations, which are the walls of the basement.
The use of coating and spraying materials to waterproof basement walls from the outside is permissible only in dry sandy soils, when groundwater is far away and the perched water quickly drains through the sand. In all other cases, especially with a possible seasonal rise in groundwater, it is necessary to do roll waterproofing in 2 layers using modern materials based on fiberglass or polyester.
If the foundation is made of FBS blocks, before waterproofing it, it is advisable to cover the seams between the individual blocks with a plaster waterproofing mixture, at the same time leveling the surface.
5) Slab foundations.
Foundation slabs (basement floors) are traditionally protected from moisture from below by gluing two layers roll waterproofing onto a pre-filled concrete preparation. The second layer is spread perpendicular to the first. This was discussed in more detail in the article.
To avoid damaging the waterproofing layer during subsequent work, try to walk on it as little as possible, and cover it with extruded polystyrene foam immediately after installation.
At the end of the article, let us pay attention to two more points. Firstly, when the groundwater level rises above the basement floor level, drainage must be done (a system of drainage pipes laid around the perimeter of the house and wells for inspection and pumping of water). This is a big topic that will be discussed in a separate article.
Secondly, the layer of vertical waterproofing of the foundation requires protection from damage that can occur during backfilling and soil compaction, as well as during frost heaving of the soil in winter, when it sticks to the waterproofing and pulls it up. This protection can be achieved in two ways:
- the foundation is covered with a layer of extruded polystyrene foam;
- install special protective membranes that are currently commercially available.
Most builders prefer the first method, because... it allows you to “kill two birds with one stone” at once. EPS also protects waterproofing and insulates the foundation. The insulation of foundations is discussed in more detail
To make the building more reliable and stand for a long time, you need to think about this initial stage construction. Most all building materials are porous and tend to absorb water. Moisture dissolves salt crystals; with constant wetting and drying, the structure of materials gradually deteriorates and their strength decreases. Naturally, this reduces the strength and reliability of not only the foundation, but also the building itself as a whole. Water is the constant enemy of building materials also because when it freezes, it increases in volume by up to 10%. As a result, this creates a pressure in the pores of the material in excess of 200 MPa. Even the most durable materials such as brick, concrete and natural stone cannot withstand such internal pressure and form microcracks. If you don’t know how to treat the foundation against moisture, it’s worth considering two options, each of which has its own pros and cons.
Waterproofing
The choice of waterproofing method depends on the purpose of the building under construction and the type of foundation. The climate of the area and soil characteristics are also taken into account; only correct calculation can guarantee the reliability of the chosen option. Waterproofing can be vertical and horizontal. Vertical waterproofing settles down with outside foundation. At the same time, it is correct to apply it to the level of the blind area or sidewalk. This way the foundation will be protected from groundwater. Horizontal waterproofing is performed to protect basement walls from moisture. It is from the water that penetrates from the base of the foundation. This happens through the capillaries of the materials used in construction. In any case, waterproofing forms protective layer, preventing water from penetrating into the structure of the building material.
Waterproofing can be liquid, roll or film.
In addition, waterproofing prevents the penetration of air, which worsens the microclimate of the room. The second method of removing moisture does not have these disadvantages.
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Hydrophobization: process features
Hydrophobization will not only protect the foundation from moisture, but will also allow it to breathe. For this process, water repellents are used - organosilicon compounds that are diluted with organic matter or water. Among them there are those that not only protect the material from moisture penetration, but also give additional protection from dirt and dust.
- Walls impregnated with a water repellent are also protected from graffiti, from this we can conclude that the protection is quite reliable. After all, you can often see graffiti on the walls of serious establishments, but this means additional costs for repairs.
- Also, the foundation and walls treated with a water repellent become more frost-resistant, their thermal insulation increases, their service life increases and the microclimate in the building improves due to the fact that the materials can “breathe”.
- This impregnation will protect the surface from mold, because fungus will not form on a dry surface. When using colorless impregnations natural color the building material does not change and lasts much longer than without such a coating.
- Some formulations allow you to process wet materials. Efflorescence, which is the name given to the salts contained in building materials and protruding on the surface over time.
The essence of the protection is that after treatment a hydrophobic coating is formed on the surface, a thin polymer film, which, when exposed to water, closes the pores and prevents moisture from entering inside. Water repellents remain in the pores of the material for many years, that is, it also provides long-term protection.
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How to treat the foundation
Before treating the foundation with a water repellent, you need to walk over the surface with an antiseptic.
You can treat the foundation from moisture by purchasing ready-made solutions or their concentrates. The method of applying them to the surface to be treated is quite simple and does not require any special expensive tools or special skills; you can use any of the proposed tools:
- roller;
- brush;
- spray.
Any of these tools are suitable for comfort from moisture. If you are not using a spray bottle, you will need a convenient container for the protective liquid.
- If you are using a concentrate, then carefully read the instructions and find out in what proportions it should be diluted. If you purchased a ready-made solution, you can start working right away, but first prepare the foundation surface for processing.
- If the surface to be treated is already affected by fungus, mold or efflorescence, it should be treated with special chemical solutions or antiseptics. When treating walls with loose plaster, it must be removed mechanically.
The water repellent is applied in a uniform, generous layer over the entire surface to be treated until a shine appears. If the material is highly porous, the solution is applied in two layers, with an interval of approximately 10-15 minutes, for more effective protection from moisture. Most water repellents are recommended to be used in dry weather, since otherwise the hydrophobic effect is reduced. The foundation must be completely saturated with water repellent, so calculate required amount liquid is necessary taking into account the porosity of the material.
Foundation elements: not only concrete surface The foundation can be treated with a water repellent, but also its wooden, steel or iron elements. This will also give them protection from moisture, and therefore from rotting, corrosion and will significantly increase their service life.