- Swimming pool at their summer cottage: is it so expensive and how to make it cheaper
- What is better to make the bottom and walls of the bunker
- The next step is a breakdown of the construction area
- Bottom slab reinforcement
- Bottom slab concreting
- Number of reinforcement for wall reinforcement
A private pool is considered to be an item of special luxury and a pipe dream of the common man. But is it really that difficult? In this article we will tell you how to independently create an artificial reservoir – a pool – on the site of a summer cottage or a country house.
In the classification of structures, concrete pools and reservoirs are on the top lines in terms of complexity and high cost. The construction of these objects is carried out by serious organizations with a staff of designers and executors at their disposal. Their services are very expensive as they use the most modern materials and technologies. Thorough studies of soils, time-consuming calculations of loads, expensive polymeric and natural materials, multilayer technology – all this makes the final cost of the pool sky-high. Moreover, all points are carefully justified..
We will try to break the myth that a private pool is not available to a middle-income homeowner. The main factor on which we will rely in our actions will be the reliability and availability of reinforced concrete as the main building material. We use the technology used to build monolithic frames of skyscrapers. By minimizing the number of finishing layers, we save time and money.
Of course, the goal is not to compete with expensive “branded” products in terms of beauty and functionality. However, with the main task – water storage for water procedures – our future pool will cope no worse than elite competitors.
Any body of water radically changes the appearance of the site. It can become a dominant solution to the appearance of the landscape. We approach this issue from a practical point of view and propose to create a reservoir that can not only be contemplated, but used for its intended purpose – for water procedures.
All pools are subdivided into indoor and outdoor. As a rule, indoor pools (reservoirs) are arranged with high requirements for the properties of water and the environment, as well as for year-round operation. In special rooms, it is possible to place bulky and expensive filters, heating and air conditioning installations, circulation pumps, and automatic maintenance systems. Usually these are public pools and dolphinariums.
Outdoor pools are much cheaper and simpler, but they require regular labor-intensive maintenance. Swimming pool cleaning (in the West) is considered a hard and thankless job. But everything changes when a person is courting his own, built with his own hands, “child”.
The “zero point” in the decision-making process will be the conditions under which the device of an open bowl will be impossible or not recommended:
- In harsh winters. The average temperature in winter is not lower than -20, the minimum is not lower than -25.
- On floating and unstable soils (if the soil is not reinforced).
- Closer than 2.5 meters to capital buildings with foundations.
- Surrounded by trees shedding abundant foliage and having a developed root system.
Swimming pool at their summer cottage: is it so expensive and how to make it cheaper
In general, the pool is not a cheap pleasure. Its cost can skyrocket, but we will consider the possibility of creating a base – a pool bowl with an emphasis on maximum affordability for the budget of the average Russian.
The first thing we have to do is decide on our wishes. Dimensions, shape and depth are the main indicators that will form our estimate. Speaking about the choice of the shape of the bowl, we note that rounded sides without straight and even corners (circle, oval, curly) better hold the load, but the complexity of their construction makes you think. Such forms may be beyond the power of a non-professional. Or you have to pay generously for the services of a specialist. Therefore, we propose to dwell on the option of a rectangular or square shape, as the easiest to build. We will increase the load-bearing capacity due to the thickness of the walls and thicker reinforcement. The ideal shape with even corners is a regular square. It ranks second in terms of geometric rigidity after the triangle..
An interesting fact: the word “build” comes from the action “build, build”, that is, give a triangular shape, strengthen the structure.
Since a square-shaped bowl is more of a font than a pool, we will take a rectangular bowl with a classic aspect ratio of 2: 1 (4×2 meters) as a standard. Also, we will provide a supporting blind area in advance..
In this article, we will not complicate the design with the device of niches, steps or a bottom with a variable level. For the convenience of calculations, we will take the net depth of the bowl as 2 meters. Subsequently, you can substitute your own data into the formulas.
Pool plan: 1 – bowl; 2 – drain; 3 – blind area; 4 – side
What is better to make the bottom and walls of the bunker
Several answers suggest themselves – brick, cinder block, concrete. The first two would be fine if it doesn’t need to be filled with water. The pressure of sixteen tons of water must be compensated for by walls of special strength. In our conditions, such strength can only be ensured by a reinforced concrete structure made with strict adherence to technology. The second reason is the absence of seams, i.e. uniform distribution of the load over the entire surface.
The next step is a breakdown of the construction area
Here it is worth paying attention to the possibility of approaching equipment (a small excavator and a concrete pump). When digging a pit, there will be a rather large temporary dump – about 50 m3.
An important point – after the end of the work, there will be about 16 m3 dumping soil. Provide in advance where it can be identified or taken out. For storage of material and reinforcement work, you will need free space next to the pit (about 40 m2).
Excavation. The depth of the pit is 2 meters. If there is a possibility of equipment access, we recommend using the services of an excavator – this will save a lot of time.
The dimensions of the pit will be equal to the dimensions of the bowl in the plan plus one meter on each side.
The initial cut will be: V = (a + 2) x (b + 2) x 2 = (2 + 2) x (4 + 2) x 2 = 48 m3, of which backfill about 28 m3.
When the pit is ready and the bottom is cleaned, you need to arrange drainage in case of groundwater occurrence. It represents ordinary channels 30×30 cm filled with coarse gravel or crushed stone (fraction 40–80). They are laid along the future walls and under the bottom of the bowl along the entire length of the pit. Lay the bottom and walls of the channel with geotextiles before backfilling the gravel. Now you need to make a technical concrete screed, which is colloquially called “footing”.
Sectional pool: 1 – drainage; 2 – foundation; 3 – expanded polystyrene 100 mm; 4 – expanded polystyrene 50 mm; 5 – pit side; 6 – primer; 7 – branch pipe
At this stage, we recommend laying a 50 mm diameter outlet pipe in the center of the future bottom slab (at the intersection of the diagonals). The plastic soil pipe on the fittings is easy to assemble and secure before placing the concrete. The internal outlet should rise 30 cm above the level of the bottom of the pit, the external outlet should go outside along the wall and rise 50 cm above the ground level.In the future, by connecting a conventional pump to this pipe, you will greatly facilitate the maintenance of the pool.
Attention! Select in advance a filter-trap for the branch pipe and lay the foam cavity in the bottom plate according to its dimensions (before concreting).
After installing the pipe, you can proceed to the foundation device. The quality of the concrete in this case is not decisive, therefore it is advisable to make it on site. The main task of the foundation is to level the surface, prevent the soil from getting wet and prevent mixing of high-quality structural concrete with the soil (if rain catches during operation). It also ensures accurate marking and formwork setting. Layer thickness 30-50 mm.
After the concrete has set, we lay on top of a slab of extruded polystyrene foam 100 mm.
An important point: the level of the foundation should be kept in the horizon – this will greatly simplify the concreting of the slab.
Concrete consumption (volume) is equal to the layer thickness of 0.04 m, multiplied by the footprint area of 14 m.In our case: 14×0.04 = 0.56 m3, take 0.6 m3 .
As the bottom slab, a full-fledged reinforced concrete slab with a standard two-layer frame made of knitted reinforcing meshes (A3 16 mm) will be used, arranged in a mirror.
Bottom slab reinforcement
First, we break the slab by size. Be sure to check the geometry (equality of diagonals and sides). Then in the corners we drill holes into the footing and drive in the reinforcement, stretch the cords around the perimeter. The length of the reinforcement will be equal to the distance between the cords minus 2 x 40 mm (protective layer). In our case, these are: 2000 – 2 x 40 = 1920 mm and 4000 – 2 x 40 = 3920 mm.
We take the cell of the reinforcing mesh 100 mm. Such a density of reinforcement is necessary for a margin of safety, because the bottom and walls must be not only structurally strong, but also airtight.
The number of longitudinal rods – 20, transverse – 40 for one layer of mesh. In total, there are 40 longitudinal and 80 transverse ones for the slab frame..
We lay out the rods with a pitch of 100 mm and tie them with a knitting wire. Under the crosshairs of the reinforcement, we lay special plastic stops 30 mm high with a step of 4×4 cells.
Attention! Do not use welding to connect the mesh bars! This weakens the metal and leads to intense corrosion at the weld points..
In order to maintain a constant thickness of the frame, we need reinforcing stops. In common parlance, they are called “frogs” or “chairs”. They can be made from reinforcement with a diameter of 10 mm. With a reinforcement diameter of 10 mm, the net height of the limiter will be equal to the slab thickness on concrete minus 2 x 30 mm minus 2 x 10 mm. In our case: 200 – 2 x 30 – 2 x 10 = 120 mm.
Workpiece length: 200 x 2 + 120 x 2 + 100 = 740 mm, accept 750 mm.
The number of “frogs” – 20 pcs., The consumption of reinforcement 10 is 15 m.
We fix the “frogs” with a wire in a checkerboard pattern on the lower grid so that the transverse rods lay on them with a step of 1 meter. We attach transverse rods to them. Then we lay out all the longitudinal ones on them with a step of 100 mm and tie them with wire. After that, we pass the missing transverse rods between the meshes and tie them to the longitudinal.
Monolithic construction is one continuous connection of all elements. This effect is achieved by adding a framework (as the main connecting element) to the freely released bars. In our case, the slab and walls are concreted separately, so we need to leave free rods fixed in the slab frame for their further weaving into the wall frame.
To do this, bend the reinforcement rods 16 in the shape of the letter P. The distance between the working rods of the release along the axes is equal to the wall thickness minus 2 x 40 mm. In our case: 200 – 2 x 40 = 120 mm. The length of the working part of the rod is 600 mm from the concrete level. Total total length of the workpiece for the U-shaped element: 600 x 2 + 120 + 40 + 2 x 140 = 1040 mm, where 40 mm is the margin for loss of length during bending, 2 x 140 is part of the element inside the slab. We accept the length of the workpiece 1650 mm.
Calculation of the number of U-shaped elements. The principle of wall reinforcement is the same as the bottom slab, so the outlet pitch will be 100 mm. The number of elements will be equal to the outer perimeter divided by the step. In our case: (2000 + 200 x 2 + 4000 + 200 x 2) x2 / 100 = 13600/100 = 136 pcs., accept 140 pcs.
We pass the U-shaped elements under the first mesh of the slab frame and fix it with wire. Reinforcement of the bottom plate is ready, it remains to make a flanging.
The height of the board (thickness of the slab for concrete + PPR 100 mm) in our case will be 300 mm. As sides, you can use plywood strips sewn onto a beam or a 40 mm board (for bending strength). The board is installed along the cords pre-tensioned when breaking the slab and reinforced with slopes. The bottom is fixed by driving in the rods. The top cut of plywood can be filled with nails with a pitch of 500-700 mm and additionally tied to the frame with wire. The bottom slab is ready for concreting.
Reinforcement flow rate 16: 40 pcs. x 4 m + 80 pcs. x 2 m + 140 pcs. x 1.65 m = 160 + 160 + 230 = 550 m.
Bottom slab concreting
For all structural elements (bottom, walls, blind area) we recommend using factory concrete. It is supplied in auto mixers and allows large volumes of concreting in one go. This is important in our case. In order to maintain a constant thickness, make a measurement of 200 mm by welding a transverse stop to the reinforcement bar.
Be sure to use vibrators when placing concrete. A combination of deep vibration and the use of a vibrating screed is ideal..
Concrete consumption is equal to the slab volume. In our case: 4.4 x 2.4 x 0.2 = 2.11 m3, we accept 2.3 m3.
For high-quality wall reinforcement, we need to make supporting vertical frames. These are two parallel rods equal to the height of the wall (2000 mm) plus the width of the blind area (800 mm), connected by short rods at a distance according to the issues. In our case: 2000 + 800 = 2800 mm.
Welded frame: 1 – A3 O16; 2 – A3 O10; 3 – spot welding
We install and fix the frames with a step of 1 meter (16 pcs.). We set them up vertically and tie the top with a horizontal rod.
Advice.At this stage, you should determine the level of the walls on concrete – the depth of the pool (2000 mm) minus the thickness of the blind area (150 mm) and apply markers to the frames (electrical tape, paint, felt-tip pen).
The level at which the upper horizontal bar should be tied is the level of the top of the wall on concrete minus 40 mm (protective layer).
Corners are the most vulnerable points of rectangular structures. They should be reinforced and reinforced, if possible, with solid (whole) rods. At the corners, we will use L-shaped rods with equal sides of such length that they grip two vertical welded frames on each side (diagram). We recommend using L-shaped elements of two sizes – 1200×1200 mm and 1600×1600 mm, alternating them in the structure.
The number of L-elements is the wall height (2000 mm) divided by a step (100 mm) multiplied by 4 corners. In our case 2000/100 х 4 = 80 pcs.
Since it was decided to use two sizes of L-elements, each of them will be 40 pieces. Carefully checking verticality using a level, set and fix the corners. Then we fill the space with horizontal rods, taking measurements in place. We put in the missing vertical rods with a length equal to the welded frames and fix them to the horizontal.
Attention! Longitudinal overlap of the rods should be 200-400 mm.
Number of reinforcement for wall reinforcement
Vertical – perimeter, multiplied by 2 layers, divided by a step of 0.1 m and multiplied by a rod length of 2.8 m.In our case: (12 x 2 / 0.1) x 2.8 = 672 m, we accept 680 m.
Horizontal (together with G-elements) – the height of the wall is 2 m, divided by a step of 0.1 m, multiplied by the perimeter of 12 m and multiplied by 2 layers). In our case: (2 / 0.1 x 12) x 2 = 480 m. Total wall fittings: 680 + 480 = 1160 m.
For concreting the walls when making a bowl, we need a lot of formwork (the perimeter multiplied by 2 sides and the height of the wall) – about 60 m2. It is costly to manufacture and install such a number of panels on site – the cost of film faced plywood and boards is quite high and will not justify itself. In addition, it takes 5-7 working days.
We recommend entrusting this area of work to a company that professionally installs and concretes. The cost of renting inventory formwork and specialist services will be lower than the cost of purchasing the material, and the terms will be as short as possible. In our case, all work on the walls will take 2 days..
After placing the concrete, at least 3 days must pass, then the formwork is removed. We seal the sinks (if any) with a special repair mixture. Grind seams and beads with a grinder with a “diamond bowl”.
The consumption of concrete on the walls is equal to the volume of the walls – the perimeter multiplied by the thickness and the height. In our case: 12 x 0.2 x 2 = 4.8 m3, take 5 m3.
After dismantling the formwork, you can proceed to the external heat and waterproofing. Here we will use a material with combined properties – extruded polystyrene foam (PPR sheets) 50 mm thick. Thermal insulation of the pool is needed in order to prevent heat exchange of water and soil through heat-absorbing concrete walls. In other words, to avoid cooling water heated by the sun. In addition, the PPR serves as an excellent damper in case of seasonal soil deformations. Waterproofing is necessary to prevent contact with organics and soil.
We will mount the PPR sheets in the usual way – stick on the foam and fix the “umbrella” with a dowel after drying.
Question.Why dowel the sheets, because they will be pressed firmly with soil anyway.
Answer.The soil tends to be mobile, especially during the off-season (spring, autumn) with frequent freezing-thawing. This can move the sheets and compromise the tightness of the insulation..
Using the hydro level, we mark the horizon at the level of the bottom of the future blind area and stretch the cords (if necessary). We strengthen the first row of sheets on top along the cord (horizon). We mount the following sheets with a breakdown of vertical seams (should not coincide). We treat PPR with bitumen or water-dispersion primer for 2-3 times.
PPR consumption is equal to the area of the walls outside. In our case: 4 x 2 x 2 + 2 x 2 x 2 = 24 m2.
After the waterproofing is completely dry, you can start backfilling the sinuses. Since we will arrange a powerful blind area over the sinuses, the soil should be tamped or spilled when backfilling in order to avoid its natural settlement later.
We accept the width of the blind area 800 mm. We level the soil around the perimeter of the bowl and make a bed of crushed stone. We lay geotextiles on it. The level of the top of the backfill must match the level of the concrete of the walls. Bend the outlets of the reinforcement, as shown in the diagram. We impose longitudinal reinforcement with a pitch of 100 mm on the bottom row of outlets. We fix a welded masonry mesh 3 mm with a cell of 50×50 mm to the top row. If necessary, set the limiters – “frogs”. The thickness of the blind area for concrete – 150 mm.
From the inside of the bowl, using the “quick installation” dowel, we fix the plywood sheets to the concrete at the level of the top of the blind area. We install the outer flange in the same way as the bottom plate. We tie the top of the flanges with slats. Concrete the blind area with factory concrete. Optionally, you can also erect an additional side along the edge of the blind area.
Formwork for blind area
Reinforcement consumption for blind area. Width 0.8m divided by 0.1m step multiplied by 12m perimeter.In our case: 0.8 / 0.1 x 12 = 96 m, we accept 100 m.
Net consumption is the outer perimeter of the blind area, multiplied by its width. In our case: (5.6 + 3.6) x 2 x 0.8 = 14.72 m2, take 15 m2.
Concrete consumption – the outer perimeter of 18.4 m multiplied by the width of 0.8 m and the thickness (0.15 m). In our case: 18.4 x 0.8 x 0.15 = 2.2 m3, we take 2.5 m3.
Attention! Concrete gains its grade strength in 28 days. During this period, it must be moisturized and protected from direct sunlight..
At this stage, the pool is ready to be used for water treatments. However, with all its advantages, concrete has one property that is unacceptable for pools – it accumulates fungus (mold) on itself. Therefore, we have one more mandatory stage – finishing.
There are many finishing materials. The best option seems to us to be a “winter” putty for swimming pools (for example, “Planicrit winter 520” TERTA). The consumption of this putty is 1.2 kg per 1 sq. m with a thickness of 1 mm. We accept an average layer thickness of 3 mm (consumption 3.5 kg per 1 sq. M). The area of the bowl is equal to the inner perimeter times the height. In our case: (2 x 2 + 4 x 2) x 2 = 24 sq. m. All you need: 3.5 x 24 = 84 kg putties. Considering the packing in bags of 20 kg, we accept 4 bags.
The advantages of this type of finish:
- application in one go directly to concrete;
- a combination of starting and finishing layers;
- good sanitary properties;
- subject to local repair (chips, scratches);
- does not require additional alignment;
- does not require high qualifications of the master;
- does not exfoliate at a temperature drop;
- lowest cost among other options.
- toxic and flammable (only when applied);
- unassuming appearance.
All actions with putty are described in detail in the instructions
Consider the approximate cost of a swimming pool located on a site 30 km from Moscow. Prices are in rubles.
Summary table of consumption and cost of material and services
Name Unit rev. Unit price. Qty St-th Note Homemade concrete cub. m 1000 0.6 600 For foundation Factory concrete BSG М250, В-20 cub. m 4000 ten 40,000 Bottom slab, walls, blind area. With delivery. Rebar with a diameter of 16 mm run. m 25 1800 45000 Bottom slab, walls, blind area Armature with a diameter of 10 mm run. m 15 20 1500 Frog limiters, auxiliary rods Knitting wire Kg one hundred 20 2000 Knitting frames Extruded polystyrene foam 100 mm cub. m 5000 1.4 7000 Under the bottom plate Extruded polystyrene foam 50 mm cub. m 5000 1,2 6000 Outside the walls Primer Kg 50 20 1000 Waterproofing Putty for the bowl TERTA “Planicrit winter 520” bag 450 4 1800 Excavator services cub. m 400 50 20,000 Excluding sinus backfill Construction of concrete walls cub. m 2700 ten 27000 Includes formwork and reinforcement work Services of auxiliary workers, excavators person / hour one hundred 40 4000 Cleaning the pit, PRR *, filling the sinuses Fare – 5000 – 5000 Delivery of fittings, PPR, other materials for 30 km Total cost of material and services 160300 Cost of 1 cubic meter m pool 10000
* -PRR – loading and unloading operations
When using the pool, you should pay attention to the following points:
- Clean the bowl and filter as soon as it gets dirty with special products.
- For preservation for the winter, a prefabricated insulated wooden cover with two vents should be made. Install a fan heater with a relay at + 5 … -10 degrees in the bowl.
- Cover the lid on top with waterproof material (polyethylene, roofing felt) for the winter.
- Do not use the pool in winter for other purposes (for storing vegetables).
If you follow these simple rules, your pool will last for many years. If the pool suddenly gets bored or becomes unclaimed, its bowl can serve as a foundation for any structure, even a brick one, in which there will already be a finished basement.