Nowadays, when the field of building materials is rapidly developing, there are many types of foundations that differ in characteristics, type and purpose. But lately, among professional developers, the slab foundation is becoming more and more in demand. This type is especially convenient for owners of plots with land in poor condition. And also, this option is considered one of the available. Even a person inexperienced in repair work can fill the foundation slab on their own, without putting much effort.
Table of contents:
The most important feature of a slab foundation is a shallow foundation, which is made of a concrete pad. This property allows it to fulfill its purpose even on moving ground. Any other type of foundation will be covered with cracks when soil moves, therefore, in such areas, it is necessary to use exclusively slab.
This base is perfect for the construction of houses where harsh substances are used. It prevents deformation of the structure.
Buildings that have low floors in comparison with the ground should be erected using exclusively slab foundations. When using it, there is no need to build a basement floor and grillage.
Before you start choosing this or that product, you need to weigh all its pros and cons. Let’s start with the positive qualities of the slab foundation:
- It is reliable and durable. And it’s hard to argue with that. Interview specialists who understand building materials, and all as one will say that tiled is the most reliable type of foundation.
- Has a large area of support on the ground, and if it is laid correctly, then the soil will not adversely affect the foundation in the cold season.
- The slab foundation is versatile. The fact is that the technical characteristics that it possesses allow it to be laid on almost any soil. Therefore, this type is most often used in areas where no other foundation could cope with the task.
- The ability to install the foundation above the freezing depth of the earth. This plus was made possible by the massive sand and gravel cushion, which prevents the impact of the soil in the cold winter..
- A high level of rigidity, which prevents the house from sinking, and if this happens, the room will not suffer significant damage.
- No need to install a sub-floor.
- The lightness of the device technology, which allows you to do the work on your own and save on the services of a master.
- Suitable for any type of low-rise building. The only thing to consider is the thickness of the slab (the lighter the room, the thinner the slab).
- Can withstand ground movement. It is possible to build a house on floating lands, since the tiled foundation will not burst and burst, but will simply begin to move with them. This property is to keep the building intact.
It should be borne in mind that all the previously listed advantages will be valid only subject to strict adherence to the installation rules. If in the process of laying there are violations of technology, then the pros can turn into cons.
As with any foundation, there are some negative qualities:
- One of the biggest drawbacks that buyers see is the price. The high cost is justified by a large amount of concrete, reinforcement, sand, and crushed stone, in contrast to analogues. But on the other hand, the money spent quickly pays off. The tiled foundation will not need frequent repairs, expensive maintenance, moreover, it will function like the floors of the first floor, which will also reduce costs.
- It is not recommended to lay a slab foundation under a house that is located on an area with a steep slope. In this case, leveling the ground, or installing a basement floor, will be the way out, but this is quite an expensive pleasure..
- There are difficulties in building a basement. In the case of building a basement, you will have to fill in a monolithic slab under it, which will cause significant losses to the owner.
- Difficulties in installing the foundation on winter days. To pour concrete in subzero temperatures, you will need to spend money on heating it and maintaining heat around it..
- Difficulties in wiring communications. You need to think about the location of the plumbing, electricity, etc. before the start of pouring concrete, because after that it will be impossible to do it.
As you can see, the slab foundation has a large number of advantages, and the disadvantages can be circumvented, however, it will cost additional costs.
Before starting work, it is necessary to calculate the slab foundation: the dimensions of the formwork, the number and diameter of the reinforcement, the volume of concrete. All these values can be found using a special calculator. To do this, you will need to enter the grade of concrete, the width and length of the slab (in meters) and its height (in cm). Further, the program itself will calculate the amount of materials required for arranging the foundation.
Also, before starting work, it is worth deciding on the type of tiled base. There are several options. The main ones are:
- ordinary concrete pad;
This type is used during the construction of buildings with a basement. A hole is dug, a concrete cushion is placed, on which, in the future, the base is installed. The entire load falls on the strip foundation.
- base with stiffeners;
It is the best option among all, because it has high strength. Its construction requires more materials and efforts, therefore its technical characteristics are superior to other types of foundations..
Preparatory work also includes the assembly of a set of materials:
- steel rods;
- crushed stone;
- material for waterproofing (geotextile is most often used).
You will also need some tools for the slab foundation:
- transport wheelbarrow;
- welding machine;
Instructions for the construction of a slab foundation include several stages:
1. First of all, we conduct a geological survey of the earth, identify places with strong elevation differences.
2. We mark the future foundation.
3. Remove the soil layer and level the area where the construction will be carried out.
The choice of pit depth directly depends on the type of construction (shallow or recessed). If we consider a shallow foundation, then it will be enough to remove 50-70 cm of earth. The dimensions of the pit are selected taking into account that they should be 1-2 meters more than the length / width of the foundation. After digging, be sure to compact the soil.
4. We design and install the formwork (strong wooden boards are suitable for its construction).
5. We dig several trenches in a pit and put waterproofing in them.
6. Lay plastic pipes on top of the waterproofing.
7. Fill the bottom with a mixture of sand and gravel, distribute it evenly and tamp it.
8. We assemble the double reinforcement cage and tie it with a special wire.
For reinforcement, only rods with ribs are suitable. They will provide high-quality adhesion of the frame and concrete mix, as well as prevent stretching of the foundation slab. Using smooth rods in the work, the base will crack at the first subsidence of the soil. The reinforcement is laid in increments of less than 30 cm.If the distance is increased, the strength of the base will significantly decrease.
9. We put plastic pipes in places where various communications will be located.
Before installing them, it is necessary to cover them with sand and carefully tamp the backfill. Pipes must be laid before the start of pouring, since it is forbidden to make holes in concrete.
10. Fill the monolithic slab with concrete mortar.
The slab foundation is poured immediately. The concrete solution must be kneaded once and a large amount, so that it is enough for the entire pouring. This work is quite laborious, so ideally it should be done by four people. We lay the concrete in even, horizontal layers. It is necessary to fill it in such a way that the plate does not deviate from the horizon. To prevent such slopes, we create stiffeners in the lower part. These are trapezoidal concrete strips. Pour the last layer very quickly. Use a mixer or concrete pump for this..
11. Thoroughly smooth and level the surface.
12. Cover the resulting foundation with foil and leave it for a couple of weeks. Remember to moisturize the structure for the first five days..
To reduce the cost of work, you can knead concrete at the site of the foundation construction with your own efforts. But in this case, you will need a special concrete mixer. It perfectly mixes all components without forming lumps. This unit operates at a power of 250 watts and above. At a time, you can get from 50 to 250 liters of solution. But the quantity greatly affects the running time. If we take a small apparatus as an example, then it will take about 5 hours to create 1 cube of filling..
An important point is the location of the concrete mixer, it should be located near the base. This will reduce the amount of force you apply..
Of course, there is an option to independently knead concrete for a slab foundation using a shovel, but this will greatly affect the quality of the future foundation..
Of course, the best option would be to insulate the foundation to achieve a warm room temperature all year round. For this, various insulation materials are used. The most popular of these is styrofoam. Just 10 cm of the layer will be enough.
Also, there are different types of insulation. We recommend using sub-fundamental. Insulating material is placed directly under the stove.
Use the tips below to make your job easier:
1. To create a high-quality base, you need to use only solid reinforcement and concrete mix.
2. The use of a shallow foundation will reduce the cost of building materials by approximately 35-45% of the cost of an underground room.
3. It is very important to consider the thickness of the slab. For example, choosing a base thickness of 20 cm, it will be necessary to “reinforce” in some places where there is too much load. At 25 cm, it becomes possible to knit the frame from the reinforcement uniformly, without resorting to additional reinforcements. A 30-centimeter thickness will contribute to an increase in the strength and durability of the foundation, but at the same time it will make you spend a lot on concrete.
4. When making a pillow from sand and gravel, the material must be laid in layers. One layer should not exceed 12 cm. After each laying, tamp thoroughly. If your pillow will be composed entirely of sand, be sure to moisten the layers..
5. Before the installation of the insulation material, the pillow must be covered with a thick plastic wrap to prevent water leakage from the concrete solution. It is advisable to glue or solder polyethylene at the joints, or overlap sheets.
After reading this article, everyone will be able to make sure that the construction of a slab foundation is a fairly simple process and is possible when creating it yourself. The main thing is to follow all the rules of filling and construction technology. If this is done, then your foundation will serve correctly, for many years..
Also, we suggest looking at the step-by-step instructions on how to properly build a slab foundation video is located after the article.