Country areas with ideal hydrogeological conditions are extremely rare. Basically they come with natural flaws, which can and must be dealt with. So, to combat the groundwater and flood water, wall drainage of the foundation is constructed. To work effectively, you need to know the specifics of the device. Do you agree?
We suggest to get acquainted with the rules of the construction of near-wall drainage, tested in practice. Reliable information is useful to owners who want to make their own water drainage system. The article will also be useful for those who order work in a profile company in order to control their quality.
We have spelled out a step-by-step technology for the installation of a system that drains the soil next to the base of the house. The article provides recommendations for the operation of drainage. In the analysis of a difficult topic will effectively help photo and video applications.
The content of the article:
- Purpose of wall drainage
- The principle of the drainage system
- Step # 1: Planning and Performing Calculations
- Step # 2: Preparing Materials and Tools
- Step # 3: Select Drainage Pipes
- Step # 4: Trenching Device - Excavation
- Step # 5: Waterproofing the foundation with a membrane and bitumen
- Step # 6: Laying the pipeline around the perimeter
- Step # 7: Installing a Drainage (Manifold) Drive
- Valuable tips and tricks
- Conclusions and useful video on the topic
Purpose of wall drainage
Quite simple, but designed according to a precisely calculated project, the drainage system performs several important functions.
For example, it effectively protects the basement (if available) from the basement or the basement, which is usually equipped with both cottages and small country houses of temporary residence.
Deciding on the need for construction activities should be based on two "signals": the location of water horizons at a distance of less than half a meter from the lowest point of the foundation or the probability of the appearance of a water pipe in dangerous proximity to the building.
Another reason for the device of the wall drainage of the foundation - an aggressive composition of groundwater. The substances dissolved in a liquid medium have a negative effect on the base material, destroying it over time. In this case, it is necessary to calculate the feasibility of double protection - drainage and reliable waterproofing.
An all-round wall drainage system drains a large area around the perimeter. buildings, while draining nearby ornamental and small architectural forms landscape
In case of violation construction of a blind area or permanent water leaks in the basement zone (for example, in case of improper installation of drainage equipment) shifts occur in heaving soils saturated with excess moisture. To avoid deformation of concrete or brick structures, drainage is also necessary.
Sometimes in the process of building a building it is necessary to carry out activities that provoke a change in the location of groundwater. Accordingly, in these cases it is also necessary to take care of the functional drainage system.
Here is a list of some unwanted design decisions:
- the device near the construction of closed areas without proper pumping of fluid;
- insufficiently thought-out system of drains and elements of storm sewer;
- equipment near the house of a pool, pond or other reservoir with a disturbed filtration system and emergency drainage;
- violation of building construction technologies (backfill filtration coefficient is not considered);
- retaining walls are installed in the ground to prevent the outflow of water.
Each of these factors at any time can cause flooding of the foundation, which will later be difficult to cope with.
If we take into account the statistics, the wall drainage is the most common type of drainage in private property. It protects the structures better than others from the destruction by water, which necessarily appears during heavy rains or spring thawing of snow.
Measures for the installation of drainage structures are performed, based on the provisions of SNiP 3.07.03-85 (specifically on drainage) and SNiP 3.05.05-84 (on pipelines).
The principle of the drainage system
The action of drainage is fully consistent with its main purpose - the removal of excess moisture to a safe distance. It would be a mistake to assume that one pipe laid along the perimeter of the house can cope with this problem.
In fact, it is a whole engineering and construction complex, which fights against an excess of moisture, protecting foundations and basements, but without overdrying the surrounding area.
Wall drainage type is advisable in conditions of clayey soil and loams, when thawed, rainwater and groundwater cannot independently leave the zone located around the building. The complex construction of pipes, wells and outlets removes excess water quite effectively, despite the budget cost.
One of the simplest designs of wall drainage: installation of drains around the building’s perimeter, inspection wells at the corners (sometimes two are enough), retraction outside the garden area (+)
One of the popular schemes involves the connection of two systems - drainage and storm - in the zone of the accumulation well, which is usually located at the lowest point of the territory adjacent to the house.
In practice, it is often used option when the drainage pipe is cut into the manholes storm sewer. However, this is possible only under one condition - if the total amount of waste does not exceed the norms calculated for the installed equipment.
If the discharge zone is located above the water level in the tank, it is necessary to install pumping equipment. The popular option is the submersible. drainage pumpmatched by power.
There are two options for arrangement drainage around the foundation: traditional and more reliable. Traditional - is the installation of pipes with gravel filling, filter and clay lock. Its performance has been proven for decades.
The clay lock, which is one of the important elements of the system, is tamped in layers to increase the water resistance. It cuts off the groundwater from the basement, thus creating an insurmountable barrier to water (+)
More reliable modern drainage differs in design of the base. A geomembrane is fixed over its entire width, the characteristics of which are not inferior to a clay castle.
The installation of the geomembrane is more economical in terms of the device: you do not need to dig a deep ditch, look for the right grade of clay, transport heavy loads to the construction site, remove excess soil (+)
The installation process is much simpler if only because it is not necessary to do calculations and calculate the angle of inclination of the clay “plug”. Now almost all wall drainage schemes include the use of a geomembrane, because it is reliable, practical, fast and efficient.
The process of the device drainage for the foundation can be divided into several stages. The first step is to create a project that is best left to a professional engineer. The project should contain general drawings and diagrams, a detailed description of the drainage equipment, an action plan, an estimate.
Step # 1: Planning and Performing Calculations
According to the standards, the drains are laid along the walls of the building at the level of the foundation base or below it on 0.3-0.5 m. This prevents the accumulation of moisture in the upper layers and provokes the drainage of groundwater to the lower levels. Slope parameters are standard - 0.02 m per meter of pipe.
Suppose, when taking into account the norm, the difference between the beginning and the end of the 40-meter pipeline is 0.8 m (2 cm x 40). These calculations are important for trenching equipment.
If the house is a simple rectangular configuration, manholes arrange only 2 corners. Larger buildings with a more complex shape are equipped with 4 wells.
Throughout the pipeline, it is necessary to withstand the slope from the upper points towards the accumulation well, which is located at the lowest point in relation to the whole site. Removal from the well is also laid with a slope - but already in the direction of the gutter (ravine, reservoir)
When calculating the total length of the pipeline, we do not forget that it will be located at some distance from foundation, that is, the length of a branch along one wall will be at least 2 m longer than the length of the walls.
If it is not possible to provide a gravity system, it is necessary to connect pumping equipment. When choosing a drainage model, pressure (height of water rise) and performance are important. The optimal power of household models is 400-1000 watts.
Step # 2: Preparing Materials and Tools
With the advent of new building materials on the market, designing a drainage system has become much easier. Polymer pipes and fittings for them, elastic insulation, geomembrane, geotextiles - all of these products can be purchased at the building supermarket.
You do not need to prepare, as before, special solutions for waterproofing the foundation or look around the area for clay with special technical characteristics.
So, to trench the device will need the following tools:
- pickaxe or crowbar;
- tamper for sealing backfill.
The main tool - working hands, the more of them, the faster the process of digging and backfilling.
If necessary, you can rent a mini-excavator and a truck for the removal of soil. The equipment is usually necessary for digging a deep pit, and for arranging the drainage of a country house, ditches can be dug by hand.
For the pipeline system, polymer pipes (HDPE, polyvinyl chloride, polypropylene) are needed, as well as couplings and elbows of similar material. Does not interfere and sealant for exterior work.
If the area of pipe laying is not below the level of freezing, as recommended by SNiP, and at a shallow depth, artificial insulant may be required to prevent the formation of ice and ice plugs.
The device of the filtering layer is made with the help of geotextile and crushed stone (gravel) backfilling with a fraction of 0.3-0.4 cm, you will also need coarse sand. For waterproofing, you can use traditional bitumen mastic or profiled membrane, but it is better to use the combined method of protecting the foundation.
Step # 3: Select Drainage Pipes
Separately, we will focus on the choice of drainage pipes, because they are the main parts of the drainage system. According to the recommendations of the SNiP, it is possible to use ceramics, asbestos cement and plastic, but recently the first two options are practically not used.
Ceramic and asbestos-cement products are heavier than polymer analogues and have a more fragile structure. Plastic pipes (drains) differ in small weight that is welcomed when transporting and installation, and also high rates of durability and wear resistance.
Material for the production of pipes - PP, HDPE and PVC. Plastic drains are not deformed under the pressure of the soil, they tolerate an aggressive composition of groundwater, have a long service life (up to 40-50 years).
Along with polymer pipes, fittings of the same material are used: couplings, adapters, tees. A set of fittings should be purchased with drains
The main difference between drains and ordinary pipes is the cuts, which, when laid, are located on the sides. To protect the holes from clogging with soil and sludge pieces, an effective geotextile filter is used. There are smooth and corrugated types, the latter are more elastic and at the same time rigid.
The choice of the type, section and method of installation of drains depends on the type of soil and volume of water. For example, if macadam soil predominates at the construction site of a building, no additional measures are needed to create a filter - just dig a trench and install a pipeline.
An economical and practical version of drains - pipes with a geotextile layer. Factory filter wrap reduces installation time and increases drainage efficiency
For pipes located in clay soils, crushed stone is required, 0.20-0.25 m thick, and in loams additional protection is required against silting in the form of geotextile winding. The structures placed in sandy ground require maximum attention: crushed stone and geotextiles are also needed.
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Almost all polymer pipes for drainage, regardless of the presence or absence of the outer winding of the filter material, have a corrugated surface with slots and holes
Choosing pipes with geotextiles, which are most effective in sand and loams, you should pay attention to the density of the material. For household needs, usually enough density of 160-200 g / m²
Coconut winding pipes are used less frequently, although they have several advantages: they consist of natural material that does not contaminate the soil, filter well and protect the pipeline
A layer of polystyrene foam can be recognized by the large volume. Artificial material excellently replaces gravel, relieves from laborious work on the transportation and laying of rubble "pillow"
Corrugated pipes with perforation
Geotextile wrap clogging
Coconut fiber - natural filtration
Polystyrene foam fillers
Step # 4: Trenching Device - Excavation
Having prepared the material, you can begin to mark the place for laying drains. To make it easier to determine the scope of work, pegs are placed along the contour of the trenches and a string is drawn between them. Earthworks is the most labor-intensive part of the drainage device.
Pulling trenches, you need to follow a slight slope of the bottom in the direction of the drive. For accuracy use a level and landmarks with which it is easy to determine the height difference.
For more accurate slope compliance usually use sand, which is part of the filter. By the way, when using factory-made decks, equipped with a geotextile layer, another “cushion” will not be needed - rather sandy.
After the excavation work, a large amount of soil will remain. Part of it is useful for backfilling, the rest of the land can be used for decorating a garden plot, lawn, garden or flower garden
Having equipped a trench along the foundation, it is necessary to dig a pit for an accumulation well and another ditch - for diversion of water outside the fence (if all the water is not planned to be used for irrigation or technical needs).
A few tips with an eye to SNIP:
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Before starting work, the site must be cleaned: remove large stones that can damage the drains, and make sure that trees with large roots do not grow nearby
You need to count on the maximum level of freezing to dig trenches even deeper. If you focus on the average level of freezing, the pipeline will burst during the harsh winter
Usually they heat the drains to avoid freezing of water in them, but in the most northern areas they also produce thermal insulation of the ditch.
In closed drainage systems, crushed stone or gravel of various sizes are used: the lower layers are covered with large stones, closer to the surface - smaller
Laying drains on crushed stone or gravel is not recommended. The basis for the installation should be a "cushion" of river sand, preferably at least 15 cm in thickness
No need to experiment with branches and building a complex drainage system. Wall drainage is always laid along the walls of the house - around the perimeter.
The well is pulled out along with the trenches. Its location is at the lowest point so that water can be collected naturally.
The inclined position of the pipes (2 cm / m) must be considered when digging a trench. First you need to make calculations to take into account the differences for the installation of the well, septic tank, etc.
Clean area in the arrangement zone
The depth of the trench is more than the level of freezing
Trenches or pipes are insulated with geotextile
Crushed stone of various fraction
The pipe is laid on a layer of sand
Trench around the perimeter of the house
Well for drains - at the lowest point
The drains are laid at an angle
Step # 5: Waterproofing the foundation with a membrane and bitumen
Waterproofing concrete parts of the foundation is necessary in any case: even if there is no utility room or storage for canned vegetables inside the basement. A dense layer of protective material will increase the strength of concrete structures and protect them from regular washing out with groundwater, if the drainage system does not cope with their volume.
Bitumen mastic is traditionally used to treat the walls of the foundation - to increase its water-repellent qualities, it is applied in several layers. In the joints of concrete structures can additionally be made of fiberglass reinforcement.
The thickness of the bitumen layer depends on the depth of laying: up to 3 m is enough 2-millimeter bitumen layer, more than 3 m - up to 4 mm. When the bitumen dries, PPM is fixed over the entire width of the foundation - a profiled polymeric membrane of the roll type.
PPM is a dense waterproof polyethylene film with a corrugated surface. Projections with a height of 8 mm to 20 mm increase the strength of the material and allow water to freely roll down.
More expensive types of PPM are initially equipped with a layer of geotextiles. There are three-layer products, further reinforced with plastic wrap. Roll roll along the basement, trying to leave as little as possible docking places.
The layout of the drains and waterproofing. The membrane is mounted spikes outward, toward the ground. In the absence of a factory geotextile layer, it is fixed separately, from the side of the projections
The principle of membrane protection is simple: water seeps through geotextiles, collides with waterproof polyester material and rolls down to drainage pipes.
Depending on the method of hydroprotection of the foundation and laying of drains, it is necessary to prepare separate construction materials:
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Unlike pit sand, river sand does not contain impurities (clay, biological particles, peat) and has a filtration speed one and a half times higher.
When arranging the drainage backfill, granite rubble is more often used; it is more frost-resistant and durable - the service life is 50 years. Limy serves only 15 years
Less effective than rubble, due to the smooth surface, but cheaper material. To increase the filtering ability is used in conjunction with sand.
Geofabric from natural fibers can not be used - only suitable synthetic fabric, made according to the technology of thermal bonding
Thick material made on the basis of bitumen is applied with a brush on the surface of the foundation in several layers. Plus - inexpensive cost, cons - fragility, complexity
The main material that prevents the penetration of moisture - bitumen or a modified polymer deposited on the base
Brush applied to concrete blocks penetrate into the porous material, crystallize, increase frost resistance, strength and resistance to aggressive media
In the cottage and low-rise construction is often used ready-to-install material - profiled membranes. They come from PVC, EPDM, thermoplastic polyophene
Large and clean river sand
Gravel - river or sea pebbles
Geotextiles for pipe protection and filtration
Obmazochnaya waterproofing - bitumen mastic
Roll on or glued roll waterproofing
Penetrating compounds - Penetron, Hydrotex
Profiled membrane for waterproofing
Step # 6: Laying the pipeline around the perimeter
Suppose that the required slope of the trench bottom (2 cm / 1 m) is taken into account even at the digging stage.
The conventional method of laying pipes looks like this:
- A layer of sand (0.15-0.20) m is filled to the bottom.
- Spread geotextiles roll over the entire length of the trench, the edges of the canvas are fixed in the upper part of the trenches.
- A thick layer (also not less than 0.15 m) of clean rubble is poured on the cloth. After each event, check the magnitude of the slope.
- Lay pipes with a diameter of 0.11-0.20 m with holes in the side, short fragments are connected by couplings.
- If the pipes do not have a protective layer, they are wrapped with geotextile and fixed with polymer twine.
- On turns, in places of drops and connections of drains, inspection wells are arranged. It is possible to use pipes of wide section, equipped with covers (further they will be required for flushing the pipeline).
- The drains are covered with a layer of pure rubble (0.15-0.20 m).
- The free edges of geotextiles are laid with an overlap on top, for fixation they are covered with a heavy layer of clean river sand (in some cases, to the level of the ground).
At the very end, when all pipes are laid and mounted inspection wells, make backfilling - return part of the soil to the place, slightly stamping it.
The permeability of the slots or holes in the drainage pipes is an important condition for the operation of the system. Make sure the holes are smaller than pieces of rubble or gravel, otherwise filtering backfill will block the perforation.
When installing pipes, do not forget about the concrete pavement - a necessary protective element that is laid along the wall of the house. The blind area - from 0.5 m to 1.0 m.
Step # 7: Installing a Drainage (Manifold) Drive
The simplest is the scheme in which the highway is taken out of the line without equipment. drainage well. However, its presence is still necessary if:
- derived drainage water is necessary for irrigation of crops or plantings;
- additional storage is a backup storage of technical water;
- There is no way to discharge water outside the site.
In the latter case, they often equip not a reservoir, but a filtering well, which, instead of the bottom, is equipped with a powerful gravel-sand backfill filter.
For the construction of the tank using brick, concrete rings, but in connection with the progress in the manufacture of special equipment increasingly began to install ready-made factory tanks from polymer material.
If it is not possible to arrange the water output by gravity, the well will be equipped with a drainage pump. It is installed under water, at some distance from the bottom surface (submersible) or near the well (surface)
A solid plastic barrel is mounted on a flattened bottom and covered with soil. In the upper part there is a hatch through which it is easy to access the water and equipment.
Valuable tips and tricks
If you follow the rules below, the problems with the functioning of the drainage system will be much less.
- Drainage pipes are mounted along the lower boundary of the foundation base. The permissible step up / down is from 0.3 m to 0.5 m. If you lower the drains below, the groundwater and rainwater will systematically flush out the soil from under the foundation, which is fraught with the building subsidence.
- If it is not possible to protect the foundation with a geomembrane, it will be necessary to construct a clay castle.
- The level of accumulation of drainage water (drain zone) should be below the level of the clean floor in the basement or cellar.
- Backfilling with river sand is more effective than backfilling with “native” soil.
Considering the dynamic movement of groundwater, be sure to fix geotextiles when installing the pipeline. It should tightly, without gaps, cover the filter "roll".
Properly equipped drainage system is 20-30 years, so after installation, you can proceed to choose the method of improvement near the local area. One of the popular options - flower garden
For more effective removal of excess moisture along with the wall drainage install gutter system and stormwater - underground or outdoor.
Conclusions and useful video on the topic
Three interesting videos will help you learn more about drainage systems.
Video # 1. Useful information about the purpose of drainage systems:
Video # 2. Nuances of the choice of drains:
Video # 3. Drainage Tips:
A professionally designed and installed wall-mounted system is the guarantee for the protection of the foundation and basement room.Equipping your own water disposal, remember that it is better to entrust the calculations and preparation of the project to specialists, and you can implement the plans yourself.
Tell us about how you organized the drainage system for the removal of groundwater and flood water from the foundation of the house. Please write comments in the box below. Here you can ask questions, share useful information, post a photo on the topic.