Waterproofing strip foundation residential building is necessary to prevent moisture in the concrete and reinforcing elements included in the foundation structure from sedimentary and groundwater. Wetting of concrete provokes destruction of the foundation due to the expansion of frozen water in the capillaries of the concrete tape and leads to corrosion of steel reinforcement, reducing the strength properties of the foundation of the house. Owners of individual buildings are able to independently correctly carry out work on waterproofing the foundation of their home, possessing certain knowledge in this area.
The destructive effect of moisture on the foundation of a building occurs when water interacts with the materials of the foundation structure. The porous structure of concrete, saturated with capillaries, contributes to the constant absorption of moisture from concrete environment and groundwater. In order to make the strip foundation of a residential building as protected as possible from a damp environment, it is necessary, in accordance with (previously SNiP 2.03.11-85), to ensure its waterproofing using methods of primary and secondary corrosion protection (clauses 4.5, 4.6 and 4.7). Foundation waterproofing falls into the category of secondary protection, based on the use of protective coatings or treatment with special compounds.
Scheme of waterproofing strip foundation.
Builders with their own hands or with the involvement of specialized organizations carry out measures to apply waterproofing materials to the foundation, taking into account external factors, affecting the foundation of the house:
- Atmospheric precipitation and melt water;
- Groundwater.
To guarantee protection of the foundation from the penetration of sedimentary and melt water It is enough to make a high-quality blind area around the perimeter of the entire building. To implement waterproofing against ground moisture it is necessary to take into account a complex of initial data, among which the main ones are:
- Type of groundwater near the structure;
- Depth of groundwater passing near the building;
- Heterogeneity of soils in the construction area;
- Purpose and planned operation of the house.
Let's consider how these factors influence the choice of foundation waterproofing method.
Type of groundwater
Groundwater has a direct impact on the formation of groundwater level (GWL) in the area construction site and on the degree of soil moisture near the foundation. The diagram below shows the distribution patterns of the two main types of groundwater in soil:
- Verkhovodkas are local centers of water formation that have a seasonal nature of existence. Verkhovodka lies near earth's surface, is formed and exists only during times of high environmental humidity, disappearing during dry periods;
- Groundwater that occurs near the surface of the earth and has a territorial regional distribution. Groundwater levels are subject to seasonal fluctuations.
As mentioned above, to protect against high water, it is enough to make a good blind area and storm drainage. Protection from groundwater will depend on its depth. This dependence is discussed below.
Depth of groundwater
“Recommendations for the design of waterproofing of underground parts of buildings and structures” Central Research Institute of Industrial Buildings, M., 1996 (amended in 2009), determined that waterproofing of structures must be carried out above the maximum ground level by no less than 0.5 m (p. clauses 1.8 and 1.9). Since the average value of fluctuations in the level of hot water in many regions of the Russian Federation, according to the results of geological surveys, is accepted within 1.0 m, then in order to guarantee protection of the foundation from ground moisture, it is recommended to adhere to this indicator as a basic reference point when choosing waterproofing for the base of a building, depending on the depth of the hot water. . In particular:
- When the water level is less than 1 m below the base of the foundation, it is necessary to waterproof the foundation;
- If the groundwater level is located more than 1 m deeper than the foundation, hydraulic protection may not be installed.
It is necessary to take into account the possibility of increasing the groundwater level as a consequence of infrastructure development in the region. As well as the maximum groundwater level for past seasons.
At high level GW exceeding the lower level of the foundation base, in addition to waterproofing, it is necessary to additionally make local drainage to remove moisture from the foundation, as prescribed in “Design and construction of foundations and foundations of buildings and structures” (Chapter 11).
Soil heterogeneity
The heterogeneity of soils with different chemical compositions leads to chemical aggression of groundwater towards concrete in the foundation, up to its destruction (concrete corrosion). The use of special corrosion-resistant concrete grade W4 is required when pouring the foundation and highly reliable hydraulic protection made from materials resistant to aggressive environments.
Purpose and planned operation of the house
In the presence of self-equipped basements functional purpose such as a gym, workshop, etc. increased demands are placed on the reliability of waterproofing in order to prevent deterioration of the microclimate in these rooms.
Properly arranged waterproofing of the strip foundation of a residential building requires compliance with three basic principles for constructing a waterproofing system for the foundations of buildings of any purpose:
- Continuity of each layer of waterproofing along the entire perimeter of the waterproofing;
- Installation of a waterproofing layer only on the side exposed to moisture, i.e. waterproofing the foundation should be carried out outside, but in no case inside the basement;
- Preliminary special preparation of the outer surface of the foundation for subsequent application of waterproofing material.
Types of waterproofing strip foundations
According to clause 5.1.2 of the set of rules (formerly SNiP 2.03.11-85), waterproofing of a concrete structure is ensured:
- Paint and varnish and mastic coatings;
- Coating and plaster coatings;
- Pasted insulation;
- Impregnation of the surface layer of the structure or other surface treatment methods.
In relation to strip foundations, taking into account modern technologies When applying waterproofing, vertical waterproofing is divided according to the method of installation into the following types:
- Coating (painting);
- Welded;
- Plastering;
- Stickable;
- Injection;
- Impregnating;
- Sprayable.
Coating (painting) waterproofing
Waterproofing using coating technology is based on the use of bitumen and bitumen-polymer emulsions and mastics with the formation of waterproof films on the surface of the foundation.
Coating waterproofing protects the foundation from the penetration of capillary ground moisture in low-moisture soils when groundwater is removed 1.5-2 meters below the basement floor level. In the presence of hydrostatic pressure, it is permissible to use coating technology in the following options:
- Bitumen mastic is used for pressure no higher than 2 m;
- Bitumen-polymer mastic - for a pressure of no more than 5 m.
Mastics are applied in 2-4 layers. The thickness of the coating waterproofing depends on the depth of the strip base and is:
- 2 mm – for a foundation with a laying depth of up to 3 meters;
- 2-4 mm – for a foundation with a laying depth of 3 to 5 meters.
The advantages of coating bitumen protection are as follows:
- Relatively low cost;
- No special requirements for the qualifications of performers;
- High elasticity;
- Excellent adhesion.
Among the disadvantages, it should be noted the short service life - after 6 years the insulation loses its elasticity. The waterproofing layer becomes covered with cracks, which reduces the overall level of waterproofing. To increase the shelf life of the insulation, polymer additives are added that provide increased performance characteristics waterproofing coating.
The technology for applying mastic is simple. A special primer is applied to the previously prepared surface with a roller or brush, ensuring deep penetration into the foundation material. After the primer has dried, bitumen mastic is applied in layers.
Welded and glued waterproofing
These technologies relate to methods of waterproofing with roll materials. They are used both as independent waterproofing measures and as an addition to the do-it-yourself coating method. When using adhesive waterproofing, traditional roofing felt is used, which is fixed to the foundation surface treated with a bitumen primer.
With glued waterproofing, the thickness of the waterproofing layer reaches 5 mm. The use of 2-3 layers is allowed.
Roofing felt can be fixed with special adhesive mastics in several layers with an overlap of 15-20 cm. If the fixing of roofing felt is carried out by heating with a gas burner, we will obtain fusing technology. From modern materials, instead of roofing felt, roll waterproofing materials are used - Technonikol, Technoelast and other materials for fusing polyester on a polymer base, which increases the wear resistance of the coating. The service life of such waterproofing is 50 years.
Plaster waterproofing
Laying waterproofing using the plaster method is identical to plastering walls using beacons with your own hands. For insulation, mixtures of moisture-resistant components such as polymer concrete and hydroconcrete are used. Minimum thickness the applied layer should be 20 mm.
The advantages of the plastering method include the low cost of materials and ease of implementation.
Among the disadvantages it is necessary to note:
- Average level of moisture resistance;
- Short service life, after 5 years cracks appear through which water can leak.
Injection waterproofing
The injection method of waterproofing is based on pumping special polymer injector mixtures under pressure into the pores of the foundation. For injection technology, materials are produced based on mineral or polyurethane based, in density close to ordinary water. If you use polyurethane-based compounds, then waterproofing each square meter you will need at least 1.5 liters, while acrylic-based mixtures will require much less. Perforation for injection is performed with conventional hammer drills or drills; the dimensions of the holes (from 25 to 32 mm) are determined by the diameters of the injection packers and capsules. Upon completion of the injection process, the perforation is sealed cement-sand mixture regular composition.
Impregnation waterproofing
This technique is based on the impregnation of concrete with special organic binding materials that fill the capillaries of the concrete and form an anti-hygroscopic layer in the concrete up to 30-40 mm deep.
The technology of spraying waterproofing material requires the use of a special sprayer. While the cost of materials is high, their use is economically justified for waterproofing foundations complex configuration, which are difficult to process in other ways.
Drainage as an auxiliary measure
The arrangement of drainage systems is intended to remove excess moisture from the foundation system of a building at a high level of groundwater. According to clause 11.1.15 of the set of rules, drainages are divided into general and local. Their use in combination with waterproofing helps protect the foundation from the penetrating effects of ground moisture.
Do-it-yourself waterproofing of a strip foundation is difficult. technological process, requiring a clear understanding of each stage of the entire event. Only in this case will a long period of trouble-free operation of the house be ensured.
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Content
Groundwater, moisture, weather dampness - all this poses a natural threat to a building if its foundation is not sufficiently protected from water. To ensure that concrete and other materials in the foundation structure do not suffer from moisture, creating a damp atmosphere in the lower rooms, a number of works must be carried out during construction, the main of which is waterproofing the foundation. What materials and technologies are best suited for this and whether you can cope with the process yourself - find the answers below.
What is foundation waterproofing
Any waterproofing is a series of works aimed at insulation, protecting the foundation from the influence, penetration of moisture, and reducing the natural absorbency of concrete. This procedure is especially relevant if the house is located on wet soil or has basement, garage, ground floor. Exist different ways How to treat the base from moisture:
- bitumen and bitumen mastics are common;
- followed by cement-polymer compositions;
- Liquid rubber and self-adhesive roll materials are used.
What is it for?
Concrete is the main component of any foundation; it has a porous, pliable structure, so liquid from the atmosphere and soil always seeps into it, destroying the integrity of the structure, creating and increasing microcracks. Ultimately, this will lead to such serious consequences as partial destruction, rotting, and crumbling of the house at the base.
Protection from water is necessary for every building in order to increase the period of its safe, guaranteed operation, to protect the house from dampness and its unpleasant components - fungus, mold. Modern waterproofing allows you to eliminate all these dangers with the help of functional, affordable building materials and simple technology.
Horizontal waterproofing
Depending on the characteristics of the material and terrain, use horizontal or vertical view procedures. Horizontal provides good protection of ceilings, walls, plinths, terraces and balconies from capillary water, it is laid along the edge of the base, just above the level of the blind area. For implementation, a roll or impregnation method is used. Horizontal waterproofing of the foundation is carried out at the beginning of construction, before the construction of walls.
Vertical waterproofing
Use for this better light ones bitumen mixtures that insulate buildings and do not weigh down its structure. Vertical waterproofing is necessary for protecting the side walls, frame, and components doorways, underground premises, from penetration surface waters. Since this part of the building is often exposed to external factors, it is necessary to apply an additional layer on top of the main protective one.
Roll
The adhesive waterproofing of the foundation is made using materials such as roofing felt, glass insulation, glassine, which are glued in several layers using mastic or special glue. Other methods are film diffusion membranes, which have high vapor conductivity and protect the interior of the building well, or bitumen, polymer rolls attached using a hot, floating method (for better connection to the surface).
You should calculate in advance the amount of material required for horizontal protection from groundwater: the future protective layer should be about 3 mm if the base of the base is at least 3 meters. The thickness and quantity of coatings depends on the quality and strength of the material; recommended standards are often indicated on the packaging.
Coating
Bitumen insulation is used when soil moisture is low, when groundwater lies at least 2 meters below the basement level. It protects well from capillary moisture and is applied in 3-4 layers manually or using a mechanical sprayer. Material – bitumen, bitumen-polymer mixtures and rubber mastics, additional coatings with base, varnish, paint. They are available cold, soft, ready-to-use, or hot, hard, which must be preheated.
How to make waterproofing
Craftsmen recommend laying horizontal waterproofing layers before erecting the main supporting structure: clay is poured into the bottom of the pit, covered with a concrete screed, then two layers of bitumen and roofing felt and another screed. If the soil tends to retain water, it may be necessary to construct a drainage system for better protection. Foundation waterproofing occurs in several stages:
- preparing a trench at least 1 meter wide, 0.5 meters deep below the base;
- grouting of the outer layer for better adhesion to moisture-proof coatings;
- primer using the selected technology.
Waterproofing strip foundation
The strip construction is one of the most reliable, since the layers of reinforced concrete fit tightly to each other, practically without seams. It is influenced by ground, capillary and sedimentary waters, and you can choose a free-flow, counter-pressure or capillary (the most effective) method. All of them will well protect the building from melt water, rain, minor floods, and penetration of soil moisture. When waterproofing a strip foundation, it is important to take into account the degree of swelling of the soil during freezing, the characteristics of the soil, and the amount of precipitation.
Waterproofing a columnar foundation
Columnar foundation – good decision for small, lightweight structures, or to save money on large-scale buildings. To protect such a structure from moisture, use different technologies, depending on the surface material:
- monolithic concrete plates need to be coated with bitumen mastics;
- blocks - with liquid mastics or pasted over with rolled materials;
- for brick foundation would be better suited pasting in rolls.
Before waterproofing columnar foundation it is necessary to thoroughly clean, level the working surface, treat it with mastic and two layers of fixing roofing material; for complete protection can be covered with the same layer outside foundation 30 cm above ground level. This will help maintain the integrity and strength of the material and increase the life of the building.
Which waterproofing to choose for the foundation
Types of foundation waterproofing differ in the type of materials used, method of application and effect on the surface. Prices vary, so you need to choose the right method, taking into account the purpose of the building, soil characteristics and available finances. It is important to consider that not all types can be performed independently; some require special equipment and the help of other people. What methods are there:
- Coating. A cheap option, suitable for small, shallow buildings: sheds, garages, outbuildings. For better protection and insulation, you can cover the top with geotextiles or install drainage.
- Rolled. Hot bitumen mastic and several layers of roofing material are used, a reliable and durable method.
- Plastering. Helps well with the threat of capillary water. Cement-containing mixtures (hydraulic concrete, asphalt concrete) are required; they must be applied hot, just like ordinary plaster, in several layers.
- Sprayable. Using a special construction sprayer, without pre-treatment of the walls. It is recommended to lay a reinforced layer on top of the spraying to secure the insulating effect. Materials: polyurethane foam, liquid rubber.
- Penetrating. Penetrates deeply into the material, fills all cracks and depressions, and protects well from capillary water and humidity. Expensive, high quality and effective method.
- Screen. Used when there is strong exposure to groundwater, it is a layer of fatty clay, geotextile or brick wall.
How to choose waterproofing
When choosing a method to protect a house from moisture, you need to carefully study all the features of the structure and the area in which it is located (weather, soil, proximity to bodies of water). Waterproofing materials for foundations must be selected based on the estimate, without skimping on quantity and quality, so that you do not have to dismantle the structures and repair the foundation in a couple of years.
- For strip design it is better to choose bitumen or polymer compositions; penetrating or plaster coating.
- For columnar and pile-screw foundations, different methods are suitable depending on the required degree protection, but it is recommended to coat them with an anti-corrosion agent on top.
- It is good to combine vertical and horizontal protection, but if the opportunity for horizontal protection has been missed, then it is better to use the roll method or spraying with liquid rubber.
- It is better to determine the method of waterproofing at the very beginning of construction, in order to take this into account when laying and pouring the foundation.
- A combination of several methods can have a good effect.
Price for waterproofing
The cost of waterproofing a foundation of a certain type includes all the basic, Additional materials(glue, primer, roofing felt), construction work (digging a trench, ditch), and the services of craftsmen, if you use their help. You can buy everything you need in an online store with delivery, in a supermarket, or order a service on any website construction company or private specialists. Purchasing turnkey waterproofing for a house can cost 600 rubles per m2; the prices of materials are very different and depend on the composition and manufacturer.
Cost of work per m2
You can buy waterproofing for the foundation from any construction company; this procedure is often included in the general price list of the work. You can order it separately from specialists, with a complete diagnosis of the area and possible threats. Plaster and coating waterproofing are cheap, the most expensive price in penetrating, spraying procedures. Approximate prices for moisture protection work on foundations in Moscow and the region are shown in the table:
Materials
To protect the foundation of the house from moisture yourself, or to control the cost of services, you need to focus on the prices of materials. In large cities (Moscow, St. Petersburg), all possible tools, mastics, roll, and spray coatings are available for sale. Additional mixtures will be needed to treat the finished waterproofing layer. When buying material for foundation waterproofing, you can save money if you follow promotions and sales in stores: often required product You can buy it at a discount. See the table for average prices in Moscow:
Do-it-yourself foundation waterproofing
Waterproofing a strip foundation helps prevent Negative influence moisture on the load-bearing parts of the house. Since the cement base has high capillarity, moisture penetration will lead to oxidation of the reinforcement, which can lead to distortions and shrinkage of the entire structure. In the article we will look at the structure of a strip foundation, as well as methods for waterproofing its main parts.
What is a strip foundation?
The structure of the strip base is quite complex, since the structure is a closed concrete contour located on a sand and gravel bed. To strengthen the base, a reinforcing mesh is used, which consists of metal rods. The structure can be located directly on the ground or on piles, which take on the static load created by the building.
For what purpose is waterproofing a strip foundation done with your own hands? It should be taken into account that the strength concrete base During operation, sedimentary, groundwater and capillary water will have a destructive effect. To prevent damage to building materials, it is necessary to implement a number of measures to drain water from the building. These include:
- installation of a drainage system;
- laying a waterproofing cushion;
- hydroprotection of load-bearing parts of the structure (support piles, plinth, formwork).
Main types of waterproofing
After installing the strip base, it is important to ensure that moisture is “cut off” from the structure. To do this, use various waterproofing materials, namely:
- Coating - insulation occurs using polymer or bitumen compounds that prevent moisture from penetrating into the foundation;
- Rolled - materials with good water-repellent properties are suitable for finishing the base, pile-strip base ( load-bearing supports), as well as hydraulic protection of the foundation under a monolithic slab. The most popular among roll moisture insulators are roofing felt, polyethylene film, geotextiles;
- Sprayed - waterproofing agents are applied to concrete structures using spray guns. Liquid solutions based on bitumen and polymer additives are used as a spray mixture;
- Impregnating agents are mixtures of liquid consistency that easily penetrate the structure of the concrete coating, filling all the pores. Thus, it is possible to prevent moisture from entering the foundation and destruction of the reinforcing mesh.
Horizontal waterproofing
Horizontal moisture insulation – complex construction work, which prevents moisture from penetrating into concrete structures from underground. This type of water protection is needed when constructing any type of foundation:
- tape;
- monolithic;
- pile;
- pile-tape.
How to do it horizontal insulation? To provide reliable protection structures from negative impact groundwater, horizontal water protection is used. It literally “cuts off” moisture, which rises to concrete structures due to soil capillarity. To ensure quality work, you must do the following:
- Take care to lay a waterproofing cushion of sand and gravel. The layer thickness must be at least 25 cm;
- Do concrete screed with a thickness of about 10 cm, then postpone work until the cement has completely hardened (at least 12 days);
- Then they make calculations for breeding required quantity bitumen mastic, with which you need to treat the concrete strip;
- After this, the base is covered with roofing felt in several layers;
- Next, the formwork is installed to fill the second layer of screed;
- The final stage involves insulating the floor and laying the finishing coating.
To understand how horizontal waterproofing is done concrete structures, you can watch a video clip that describes the sequence of performing all the necessary work.
Vertical water protection
Vertical insulation of a structure from moisture involves treating exclusively the vertical parts of the structure, in particular the base, piles, etc. This procedure is recommended for use if there is a basement in the house. In this way, it is possible to prevent excess moisture from entering the underground space, from where it can penetrate into floor base first floor of the building.
How is vertical waterproofing of concrete structures done? In this case, to ensure water-repellent properties foundation, can be used various methods processing:
- plastering;
- pasting with roll insulators;
- spraying with bitumen compounds.
But before you make a calculation of the materials required for insulation, it is worth choosing the best option for waterproofing. Experts recommend using two methods of waterproofing at once: coating and gluing. How to do it? If there is a feeder in the building, the work progress will be as follows:
- First of all, the working surface must be coated with bitumen mastic;
- After this, cover the ground floor for the basement with technoelast (a type of roofing felt);
- When calculating rolled materials, keep in mind that they must be overlapped with a margin of at least 15 cm;
- To ensure the seams are sealed, melt them with a gas torch, causing adjacent sheets to stick together.
The structure and nuances of treating a strip foundation with vertical waterproofing are shown in the video material.
Features of foundation and basement insulation with roofing felt
Waterproofing monolithic foundation most often done using roofing felt. It can be used either independently or in combination with bitumen solutions. When covering a concrete structure with roofing felt, several important rules must be followed:
- Moisture insulation under the slab begins with the application of a bitumen solution;
- The required amount of roofing material is calculated taking into account an overlap of 15 cm;
- After this, using gas burner the insulator is softened and placed on the working elements of the structure;
- When carrying out waterproofing work to finish the foundation under a monolithic slab, you can use special mastics to seal the seams.
Moisture insulation of the structure with roofing felt should be carried out using only quality materials. Ezoelast and tehnoelast insulators are considered optimal for protecting concrete bases. The process of laying materials is clearly demonstrated in the video clip.
Moisture insulation of pile-tape foundation
How to properly insulate when installing a pile-strip foundation? The absence of a supply presupposes additional processing not of the basement of the structure, but of the load-bearing concrete parts themselves - the piles. They take the maximum static load created by the weight of the structure itself.
Why is protection needed? support pillars? Under the influence of moisture, the supports begin to collapse over time due to corrosion processes occurring in the reinforcement of the pillars. To prevent distortion and subsidence of the base, additional water protection of the load-bearing parts is required. How to protect a pile-strip foundation without a basement?
- Bored piles. Bored supports are concrete pillars, reinforced metal fittings. As a rule, they are installed in casing pipes, which do not provide the proper level of protection from moisture. During the construction of the structure, it is advisable to insert roofing material into the wells for the racks, which will play the role of formwork and waterproofing;
- Screw piles. The elements of the concrete structure are represented by steel screws that are screwed into the ground. To protect them from corrosion, the spiral legs of the piles are treated with hydrophobic anti-corrosion solutions;
- Driven piles. The supports in this case are reinforced concrete or wooden posts . To protect them, antiseptic and anti-corrosion treatment is required. It won't be superfluous special impregnation
and coating with bitumen.
Do you need moisture protection for a sand cushion? What are the functions of a sand-foundation cushion? A mound of sand and gravel that is often created during the laying process strip bases
- , performs two tasks at once:
- Cuts off water from the structure;
Helps to distribute the load evenly.
Laying a pillow is a must when constructing a basement in a house. As a rule, it is in this room that it is quite damp, which creates all the conditions for the accumulation of condensation under the floor and the proliferation of fungus. Is waterproofing of the pillow necessary in this case?
If the building itself is installed on soil with strong heaving, during the process of laying the sand cushion it is necessary to calculate the required amount of waterproofing material. It is laid on a layer of sand and gravel, which disrupts capillarity and the flow of moisture from underground into the concrete structure.
Moisture insulation of formwork
To answer the question whether waterproofing is needed for formwork or not, let’s consider its main functions. The design is designed to limit the space into which the concrete solution will be poured to form the foundation. In other words, the main function of formwork is to form a liquid solution, which, when hardened, forms the necessary geometric shape. To assemble formwork, as a rule, use, which are hygroscopic. Because of this, structural elements may be deformed, which will lead to distortion of the geometric shapes of the poured concrete base. In this case, the answer to the above question becomes obvious: waterproofing for formwork is really necessary.
What types of insulators are used for finishing formwork? For guard wooden elements formworks can be used:
- bitumen solutions;
- hydrophobic impregnations;
- water-repellent varnishes;
- roll insulators.
When calculating the required amount of waterproofing agents, it is worth noting that for formwork processing the most budget option will be painted with bitumen.
Is insulation necessary for a strip foundation?
Why is concrete structures insulated? There are three main reasons why it is necessary to insulate strip bases.
At the construction stage of a building, many craftsmen make a gross mistake, which subsequently leads to a violation of the building's structure. This mistake lies in the insufficient and poor-quality arrangement of the foundation. This means waterproofing the strip foundation and basement, if any.
It is extremely necessary to complete this stage of work, since the impact of groundwater on outside the grounds are quite destructive. Especially considering that chemical composition groundwater can vary dramatically depending on the location of the house in relation to chemical or metallurgical industry facilities, agricultural activities, etc.
The lack of waterproofing on the external walls of the basement can lead to at least dampness in it
Important: the lack of waterproofing on the outer walls of the basement can at least lead to dampness in it. IN worst case constant flooding and the resulting destruction of the premises will be his fate.
Waterproofing a strip foundation with your own hands is quite simple. The main thing is to understand the principles and technologies of performing work, and also to know about all possible types and types of waterproofing. About this in our material.
It is worth knowing that you can choose a different group of materials to complete the work. They are:
Depending on the type of materials chosen, waterproofing technology is also used.
Coating type insulation
For waterproofing strip foundations and basements, including in this case, bitumen-based materials or bitumen mastic are used. According to the type of materials, it becomes clear that the waterproofing of the strip foundation in this case is carried out by spreading mastic along the entire perimeter of the base.
To carry out work using mastic, it is necessary to perform a number of such actions:
- Free the foundation (basement walls) from debris, dust and dirt;
- Coat the surface of the outer and inner walls of the foundation with a deep penetration primer;
- After the primer has dried, use a special brush (mastic brush) to apply the mastic in an even, continuous layer so that the waterproofing does not have any gaps.
The advantages of waterproofing using the coating method include:
- Low cost of materials;
- Ease of work;
- Good elasticity of the finishing coating;
- Excellent waterproofing properties of bitumen;
- High adhesion of the coating to concrete.
However, such waterproofing also has disadvantages. The main one is the low service life of the material. Thus, the layer of bitumen mastic remains elastic and intact for only 6 years. Then it begins to crack, as a result of which groundwater still penetrates to the walls of the foundation. The problem can be solved by purchasing coating waterproofing materials with the addition of softening polymers.
In addition, the integrity of the coating layer may be damaged during backfilling of the foundation. Small pebbles can scratch the coating and depressurize it. They solve the problem by laying a protective layer of roofing felt or geotextile over the applied layer of bitumen.
Roll type waterproofing (adhesive)
Here, materials in the form of a roll are used to protect the foundation from moisture. It can be roofing felt, geotextiles, Aquaizol, Isoplast with Helastopley. Most often, such materials are used if it is planned to build a house without a basement. In this case, both horizontal insulation is used (coating the foundation plane before its contact with the walls) and vertical (applying rolled material to the base walls).
Roll materials are attached to the base of the building in two stages:
- Adhesive (using bitumen mastic as an adhesive);
- Floating (using a gas burner to melt the material and make it pliable).
The technology for installing waterproofing is as follows:
- The foundation walls are cleared of debris and treated with a deep penetration primer;
- Next, after drying, the walls are coated with bitumen mastic and sections of waterproofing material are applied, pressing them well;
- The waterproofing joints are overlapped by 15 cm, and to ensure a good fit, a torch is used to fuse the cuts together.
The advantages of roll waterproofing include:
- Long service life;
- Excellent waterproofing ability;
- Easy installation;
- High resistance to any type of mechanical impact;
- Reliability of the entire structure.
But it is worth remembering that rolled materials for waterproofing based on fiberglass or fiberglass have less resistance to deformation in contrast to materials based on polyester.
Penetrating waterproofing
This type of waterproofing of foundation and basement walls is considered one of the most effective, but also expensive. Here, the waterproofing material is based on a special mixture of cement, quartz sand and special plasticizing additives. The result is a plastic material that is applied by coating to the walls of the base and penetrates into all the pores of the base, forming crystalline solidification in the voids. They will push water away from the underground part of the building.
Penetrating waterproofing is widely used for treating the walls of basements and other underground tanks, and for treating foundations of any kind.
The advantages of this type of waterproofing include:
- High quality insulation from groundwater exposure;
- Excellent ductility during application;
- High wear resistance of the finished coating;
- Durability of the entire structure;
- Resistance to aggressive environments.
The technology of waterproofing using penetrating mixtures is as follows:
- The walls are completely cleaned and treated with a primer;
- After the primer has dried, the insulating mixture is applied with a special brush or from a spray bottle;
- The coating is allowed to dry completely.
Spray insulation
This method of waterproofing a strip foundation is one of the most modern. The method of applying insulation by spraying is widely used in roofing work, during repair work of an old waterproofing coating or to create a new first layer. In comparison with the mass of advantages, the sprayed mixture has one significant drawback - high cost.
The technology for creating a waterproofing layer by spraying is as follows:
- The walls of the foundation or basement are cleaned of debris, dust and dirt;
- The moisture protection agent is applied to the finished surface using a construction sprayer, forming a seamless smooth coating;
- For greater reliability, the sprayed mastic is reinforced with a layer of geotextile.
The advantages of this method of waterproofing are:
- Long service life (50 years or more);
- High adhesion properties of the material to concrete;
- Simplicity of work, which saves labor costs and time on the construction site;
- Absolutely smooth coating without seams or joints, which prevents the slightest ingress of moisture onto the surface of the concrete base;
- Environmental friendliness and absolute non-toxicity of the material;
- Excellent elasticity that resists any small inclusions in the soil;
- High resistance to ultraviolet rays.
If the house is built without waterproofing the foundation
Important: waterproofing the base of a new building should be carried out during the construction stage. However, it happens that a house is purchased, but there is no insulation from moisture. In this case, it is possible and necessary to save the house. In this case, you need to act like this:
- The house or basement is completely excavated along the entire perimeter of the foundation. Moreover, you need to start from the corners, moving towards the walls of the base, so as not to disturb the strength of the building.
- Now you should clean all the walls around the perimeter from dirt and dust. This should be done exclusively without the use of moisture. It is important to clear all recesses, cracks and pores of the base from soil, earth and dirt.
- All cleaned cracks should be filled with special glue for tiles or cement mortar.
- After the foundation or basement walls have dried, they should be treated with bitumen mastic.
Important: under such conditions it is better to combine vertical and horizontal insulation.
- Rolls of roofing felt or other insulation material are cut into pieces the right size and using a special gas burner is applied to the walls of the structure with overlapping joints. The pieces are placed horizontally.
- Now you need to apply another layer of material in the same way, but with a vertical orientation.
Important: at the corners of the building it is worth wrapping the rolled material and making overlaps. But, under no circumstances should you cut the waterproofing. This installation method will break the tightness of the foundation winding.
- Lastly, a drainage system and a blind area for water removal are formed.
- All that remains is to backfill the base with good compaction of the soil.
Waterproofing a strip foundation with your own hands
Review of types of waterproofing material for strip foundations. Coating, roll, penetrating and other types of waterproofing.
The distinctive feature of a strip foundation lies in its very name. It is a closed chain - a “tape” (a reinforced concrete strip laid under load-bearing walls). Thanks to the use of a strip foundation, resistance to soil heaving forces increases, while the risk of skewing or subsidence of the building is minimized.
Strip foundation - photo of a freshly poured structure
This type of foundation is constructed on dry or heaving soils. Moreover, the greater the weight future design, the deeper the foundation is laid (sometimes even up to 3 m, depending on the depth of soil freezing and the level of groundwater).
These and other characteristics are regulated by GOST 13580-85 and SNiP 2.02.01.83.
GOST 13580-85. REINFORCED CONCRETE PLATES FOR STRIP FOUNDATIONS. Technical conditions. File for download
SNiP 2.02.01-83. FOUNDATIONS OF BUILDINGS AND STRUCTURES. File for download
During construction, special attention is paid to waterproofing, since the strength, quality and durability of the structure will depend on it. In the absence of protection, groundwater and precipitation can significantly damage concrete, and the consequences can be the most tragic - from permanent dampness to subsidence and cracking of walls. For this reason, waterproofing a strip foundation with your own hands is one of the most critical stages.
Waterproofed foundation - photo
Below is the average soil freezing depth in different regions. If your region is not in the table, then you need to focus on the one that is closest to others.
Regardless of the chosen insulation method (we will talk about them a little later), you must adhere to a number of technical requirements in your work.
- You should definitely take into account the groundwater level, because the type of insulation depends on it.
- It is also necessary to take into account the conditions of future operation of the facility (if, for example, a warehouse is being built, then the requirements for waterproofing will be more stringent).
- It is also necessary to remember about the possibility of flooding during large floods or precipitation (this especially applies to loose soil).
- The force of “swelling” of the soil during frost also plays an important role (during defrosting/freezing, the structure and volume of water change, which can lead not only to the rise of the soil, but also to the destruction of the foundation).
Basic methods of water protection
Waterproofing can be of two types - vertical and horizontal. Let's consider each of the options.
Important information! When constructing the foundation, there is no need to save money and abandon the sand “cushion”. Sand is needed not only to prevent concrete leakage, but also to prevent washout of the structure.
It is carried out during the construction of the foundation, and may require Extra time(15-17 days) for preparatory activities. The main function of such insulation is to protect the base in the horizontal plane (mainly from capillary groundwater). An important component of horizontal waterproofing is the drainage system, which is installed when the groundwater level is high.
It is worth noting that under the “tape” there must be a fairly strong base, on top of which the waterproofing layer will be laid. Often, for this purpose, a “cushion” is cast that is slightly wider than that of the future foundation. In the absence of a need for high quality(for example, if the foundation is being built for a bathhouse), it is enough to prepare a screed of sand and cement in a 2:1 ratio. During the Soviet era, asphalt screed was made, but today this technology is practically not used.
The horizontal waterproofing procedure consists of several stages.
Stage 1. The bottom of the pit dug under the foundation is covered with a sand “cushion” about 20-30 cm thick (clay can be used instead of sand) and thoroughly compacted.
Stage 3. When the screed dries (this takes about 12-14 days), it is covered with bitumen mastic and a layer of roofing material is attached. Then the procedure is repeated: applying mastic - attaching roofing material. Another screed of the same thickness is poured on top of the second layer.
Stage 4. When the concrete hardens, the construction of the foundation itself begins, the surfaces of which are additionally covered with vertical types of waterproofing (they will be discussed later).
Important information! If the building is constructed from a log frame, then it is necessary to waterproof the top of the foundation, since the first crown will be installed there. Otherwise, the wood may rot.
Drainage
Drainage may be required in two cases:
- if soil permeability is low and water accumulates rather than being absorbed by it;
- if the depth of the foundation is lower than or corresponds to the depth of groundwater.
The algorithm of actions for arranging the drainage system should be as follows.
Stage 1. Along the perimeter of the structure - approximately 80-100 cm from the foundation - a small pit is dug, 25-30 cm wide. The depth should exceed the depth of pouring the foundation by 20-25 cm. It is important that the pit has a slight slope in the direction of the drainage basin, where water will accumulate.
Stage 2. The bottom is covered with geotextile, and the edges of the material must be folded onto the walls by at least 60 cm. After this, a 5-centimeter layer of gravel is poured.
Stage 3. A special drainage pipe is installed on top, maintaining a slope towards the catchment of 0.5 cm/1 linear. m.
Laying the pipe on geotextiles and backfilling with crushed stone
Thanks to this design, water will flow into drainage pipe, and it (the pipe) will not become clogged. The moisture will be drained into a drainage tank (this can be a well or a pit, and the dimensions depend on the influx of water and are determined individually).
Prices for a drainage well
drainage well
Vertical waterproofing
Vertical type insulation is the treatment of walls of a finished foundation. There are several ways to protect the foundation, which are possible both during the construction of the building and after construction.
Table. Strengths and weaknesses of the most popular waterproofing options
| Material | Operational life | Easy to repair | Elasticity | Strength | Cost, per m² |
|---|---|---|---|---|---|
| From 5 to 10 years | ★★★☆☆ | ★★★★★ | ★★☆☆☆ | About 680 rubles | |
| Polyurethane mastic | From 50 to 100 years | ★★★☆☆ | ★★★★★ | ★★☆☆☆ | About 745 rubles |
| Rolled bitumen materials | From 20 to 50 years | ★☆☆☆☆ | - | ★☆☆☆☆ | About 670 rubles |
| Polymer membranes (PVC, TPO, etc.) | From 50 to 100 years | - | ★☆☆☆☆ | ★★★☆☆ | About 1300 rubles |
Inexpensive and simple, and therefore the most popular method of waterproofing the foundation. It involves complete treatment with bitumen mastic, which penetrates into all cracks and voids and prevents moisture from entering the house.
Important information! When choosing a particular bitumen mastic, pay attention to the markings - this will help you find out the heat resistance of the material. For example, mastic marked MBK-G-65 has a heat resistance (for five hours) of 65°C, and MBK-G-100 – 100°C, respectively.
Advantages of bitumen mastic:
- ease of use (can be done alone);
- affordable price;
- elasticity.
Flaws:
- low speed of work (requires application of several layers, which takes a lot of time);
- not the best water resistance (even high-quality application does not guarantee 100% protection);
- fragility (after 10 years you will have to re-treat the foundation).
The process of applying mastic itself is extremely simple and consists of several stages.
Stage 1. Surface preparation. Below are the basic requirements.
- The surface of the foundation must be solid, with chamfered or rounded (ø40-50 mm) edges and corners. In places where the vertical and horizontal transitions, fillets are made - this way the joining surfaces will be joined more smoothly.
- Sharp protrusions that appear where formwork elements meet are extremely dangerous for bitumen. These projections are removed.
- Areas of concrete covered with shells of air bubbles are rubbed down with fine-grained cement mortar based on a dry building mixture. Otherwise, bubbles will appear in the freshly applied mastic, which will burst 10 minutes after application.
Also, dirt and dust should be removed from the surface and then dried thoroughly.
Important information! The humidity of the substrate is very important indicator and should not be higher than 4%. At a higher rate, the mastic will swell or begin to peel off.
Testing the base for moisture is quite simple: you need to lay it on concrete surface a piece of PE film measuring 1x1 m. And if after 24 hours there is no condensation on the film, then you can safely proceed to further work.
Stage 2. In order to increase adhesion, the prepared base is primed with a bitumen primer.
You can go the other way and prepare a primer from bitumen yourself. To do this, bitumen grade BN70/30 must be diluted with a quickly evaporating solvent (for example, gasoline) in a ratio of 1:3.
One layer of primer is applied over the entire surface, and two at the junction points. This can be done with either a brush or a roller. After the primer has dried, the actual mastic is applied.
Stage 3. The bitumen block is broken into small pieces and melted in a bucket over a fire.
It is recommended to add a small amount of “working off” during heating. Then liquid bitumen is applied in 3-4 layers. It is important that the material does not cool down in the container, because when heated again, it partially loses its properties.
The total thickness of the waterproofing layer depends on the depth of pouring the base (see table).
Table. Ratio of bitumen layer thickness to foundation depth
Stage 4. After drying, the bitumen should be protected, since it may be damaged when backfilled with soil containing debris. To do this, you can use rolled geotextiles or EPS insulation.
Prices for bitumen mastic
bitumen mastic
Video - Insulating the foundation with EPPS
Reinforcement
Bituminous insulation needs reinforcement for:
- cold seams;
- the junction of surfaces;
- cracks in concrete, etc.
Fiberglass and fiberglass fabrics are often used for reinforcement.
The fiberglass material must be buried in the first layer of bitumen and rolled using a roller - this will ensure a tighter fit. As soon as the mastic has dried, the next layer is applied. It is important that the fiberglass material is laid with an overlap of 10 cm in both directions.
Reinforcement will ensure a more uniform distribution of the load over the entire insulating strip, minimize the elongation of bitumen in places where cracks have opened and, as a result, significantly extend the service life.
Prices for fiberglass
fiberglass
It can serve as both the main protection and an addition to the applied bitumen mastic. Typically, roofing felt is used for this.
Among the advantages of the method are:
- low cost;
- availability;
- good service life (about 50 years).
As for the shortcomings, this can only include the fact that you cannot cope with the work alone. The algorithm of actions should be as follows.
Stage 1.
Unlike the previous method, there is no need to carefully apply the material, since mastic is necessary solely for attaching the roll waterproofing to the base.
Stage 2. Using a burner, the roofing material is slightly heated from below, after which it is applied to a layer of hot bitumen. Sheets of roofing felt are joined with an overlap of 10-15 cm, all joints are processed with a torch.
Stage 3. After attaching the roofing felt, you can fill the foundation, because... additional protection not required here.
Important information! Roofing felt can be replaced with more modern materials that are fused to the base. It can be polymer films or canvases with bitumen-polymer coating (for example, Izoelast, Technoelast, etc.).
Prices for roofing material
roofing felt
Video - Waterproofing with roofing felt
This method is extremely simple to perform and is used for waterproofing and leveling the foundation surface. Here advantages of plaster waterproofing:
- simplicity;
- high speed;
- affordable cost of materials.
Flaws:
- low water resistance;
- small service life(about 15 years old);
- possible appearance of cracks.
There is nothing complicated in the application process. First, a putty mesh is attached to the foundation using dowels, then it is prepared plaster mixture with waterproof components. The mixture is applied to the foundation using a spatula. After the plaster has dried, the soil is filled in.
Essentially, it is a dispersion of polymer-modified bitumen particles in water. The composition is sprayed onto the base, providing high-quality waterproofing. Advantages this method are as follows:
- high quality waterproofing;
- no need for special skills;
- durability.
But there is also flaws:
- high cost of the composition;
- low speed of operation in the absence of a sprayer.
In addition, liquid rubber cannot be purchased everywhere. The same type of composition, which comes in two types, is quite suitable for the foundation.
- Elastomix - applied in 1 layer, hardens for about 2 hours. No further storage after opening the package.
- Elastopaz – more cheap option, however, it is already applied in 2 layers. Typically, Elastopaz can be stored even after opening the package.
Stage 1. The surface is cleaned of dirt and debris.
Stage 2. The foundation is coated with a special primer. Alternatively, you can use a mixture liquid rubber and water (ratio – 1:1).
Stage 3. After an hour, when the primer has dried, apply waterproofing material(one or two layers, depending on the type of composition). It is advisable to use a sprayer for this, but you can use a roller or brush instead.
Prices for liquid rubber
liquid rubber
Video - Treating the base with liquid rubber
Penetrating insulation
On the base, previously cleaned of dirt and slightly moistened with water, a special mixture (Penetron, Aquatro, etc.) is applied with a sprayer, penetrating into the structure approximately 150 mm. It is important that the solution is applied in two or three layers.
Basic advantages:
- effective protection;
- the ability to treat surfaces inside the building;
- ease of operation;
- long service life.
Flaws:
- low prevalence of such solutions;
- high price.
Making a clay castle
Simple, but at the same time effective method protect the base from moisture. First, a pit 0.5-0.6 m deep is dug around the foundation, then the bottom is filled with a 5-centimeter gravel or crushed stone “pillow”. After this, clay is poured in several stages (each layer is carefully compacted). The clay itself will serve as a buffer against moisture.
The only advantage of the method is its ease of implementation.
A clay castle is only suitable for wells and household objects. If we are talking, for example, about a residential building, then this method can only be used as an addition to the existing waterproofing.
This method of protecting the foundation appeared relatively recently and consists of the following: mats filled with clay are nailed to the cleaned surface of the foundation using a mounting gun or dowels. The mats should be laid with an overlap of approximately 12-15 cm. Sometimes special clay concrete panels are used instead of mats, and in this case the joints must be additionally processed.
Overlap - photo
In principle, screen insulation is an improved option clay castle, therefore can only be used for utility buildings.
To sum it up. Which option should I choose?
The optimal option for waterproofing a strip foundation should include both horizontal and vertical waterproofing. If, for one reason or another, horizontal insulation was not laid during construction, then it is better to resort to bitumen mastic or special plaster. But, we repeat, this will be most effective only in combination with horizontal type protection.