The population of the planet is growing exponentially every year. The housing issue for hundreds of families who want to have a house or apartment of the required size and, most importantly, in a "decent" place is becoming more and more relevant.
For cities with a million-plus population, this is the most burning issue. After all, there are less and less convenient territories for building, and more and more apartments are required. Many developers have begun to use all available sites, regardless of geological features.
So, the city authorities are willing to give swamp land, groundwater plots for a new construction site, etc. In order for houses to be built not only quickly but also efficiently, developers often use piles for such cases.
What are piles?
Piles are supports made of various materials: metal, concrete, reinforced concrete structure, frame, soil or tongue. They are used to make the structure more stable, less susceptible to groundwater and corrosion.
Depending on the structural features of the soil on which the foundation is poured, the developer can use different methods for installing such supports. The main criterion is the weight of the entire structure of the building, as well as the density of the land on which it will be built.
To do this, you can use a pile driver, a diesel hammer, a vibrator, a hydraulic hammer and a pile-driving machine. In special cases when stony layers are possible, a drill is used.
Even the most experienced craftsman cannot install piles in such a way that their upper part, which will hold the entire foundation, is at the same level. These supporting parts are called pile heads.
The shape of the head depends on the pile used for installation. It can be round, square, rectangular. In addition, for the convenience of mounting the base, various fastening methods can be used.
To fill the foundation under the foundation at the right level, the master needs to install a frame (grillage) on the columns, which is fixed with the help of heads.
Types and Features
The pile heads differ not only in the shape that matches the shape of the installed pile, but also in size. At the same time, do not forget that when using a screw or concrete pile, the tip will also be different.
An important nuance in the choice of heads is its shape: it can be T-shaped or U-shaped. When installing the grillage on the head of the T-shape, you can install both the formwork and the slab for pouring the foundation.
With U-shaped heads, only beams can be used, while their diameter must match the width of the tip.
The most popular on the market for a long time remain screw and reinforced concrete piles. Their cost, reliability and long service life make them the most popular.
When choosing a material, the builder is guided not only by the characteristics of the soil, but also by the magnitude of the load in the form of a mounted room. Taking into account all the nuances, the design for mounting the grillage is also chosen.
The average size of the tip of a screw pile in diameter, in its pipe part, ranges from 108 mm to 325 mm. And the diameter of the tip itself can vary from 150 mm to 200 mm.
The smallest in diameter is a 57 mm tube. Such a base can withstand a load of eight hundred kilograms. Most often they are used for the construction of light outbuildings (garage, gazebo, barn).
Wider pile with a tip diameter of 89 mm. Pillars with such a diameter are used on peat or wetlands for the construction of cottages, baths, garages, fences.
Piles with a tip size of 108 mm are the most "hardy". They easily withstand a weight of three and a half tons, are mounted mechanically and are suitable for almost all types of soils.
The concrete head of the piles has a square shape with a length of sides starting from twenty centimeters. The greater the load, the longer the reinforced concrete pile.
Screw or reinforced concrete?
The question of choosing material for piles remains open primarily because of the size of the construction site. For orders of an industrial scale (high-rise buildings, commercial and administrative buildings, bridges), reinforced concrete poles are used.
They are durable, resistant to corrosion, tolerate temperature extremes. The disadvantage of this type of piles is the high cost of installation. It is produced using special equipment.
Less expensive to install are screw piles. They can be installed using only human resources. Therefore, screw piles are most often used during the construction of country houses, small cottages.
Chipping or cutting?
In order for the structure to have an even foundation, after installation, the piles are cut at the right level. Felling of pile heads takes place using:
• jackhammer (small amount of work);
• hydraulic cutting (construction of residential complexes or shopping centers).
To make all the necessary manipulations, the master notes the desired height at which the pile will be cut. And then, if it is a concrete structure, with the help of improvised means, make a furrow and break off the excess concrete.
Leave only a metal frame, which is cut with hydraulic scissors and a jackhammer. If necessary, craftsmen can “tie” the remaining rods and the formwork of the foundation.
This method of removing "excess" is quite time-consuming and can take a lot of time. In shift masters process no more than fifteen heads.
A cheaper and faster way is to cut the ends. This method is convenient and economical. Suitable for working with various types of piles. A big plus is the high-speed processing of the ends, which significantly reduces the time of arrangement of the grillage.
For cutting, improvised cutting tools are used - a grinder, with an installed tape or disk circle; abrasive saw.
Before starting work, a cut line is marked with a marker or chalk, for a smooth saw, a groove is made around the circumference. If the tool or pile starts to heat up, they are cooled and only then continue to work.
The disadvantage of this processing method is the complete unsuitability after cutting reinforcement, as well as the rapid wear of the working tool. Which may entail additional costs for the purchase of consumables.
How to prepare for the assembly?
If metal piles were chosen for the foundation equipment, preliminary work is necessary to make the pile heads last longer.
After trimming at the level of two or three centimeters from the place of the saw, you need to remove the coating layer that protects the material from environmental factors. For this, a metal brush or a special nozzle for a grinder is perfect.
Installation of pile heads also has its own characteristics. The main criterion for installation is the type of pile and the material from which it is made. If a screw pile was used during construction, its heads will certainly be metal and fastened by welding.
It can be a T-shaped head in the form of a plate with a round base, which is worn on a pile and fastened with a weld. In addition, if a channel or I-beam is used for mounting the grillage, they are welded to the pile end in a special way.
The I-beam is fixed to the welding in the form of a square plate, and the channel is turned upside down by welding with wings to the base. If, according to the architect’s intention, the building is constructed from a wooden beam, the first “line” of logs is connected to the head with a metal rod.
For welding, electrodes with a size of 3 millimeters are used, the current value is not more than 100 amperes.
If a concrete pile head is used to install the base of the grillage, its installation begins after cutting down the pile heads to the desired level. The heads of this type are mounted in concrete mortar during the pouring of the foundation into the formwork installed on the piles.
And now for the good
The use of piles in construction is not new. But there is a possibility that not all customers have encountered their use in life. Many are embarrassed by the long process of their installation, as well as the rather laborious way of installing the grillage.
It is worth noting that the use of this type of foundation saves homeowners from many negative factors. It:
- Spring-autumn floods.
- Instability of the soil (peat bogs, swamps, quicksand, floaters).
- Convenience of installation, not depending on weather conditions (frost, heat, etc.).
- Construction of buildings on uneven surfaces;
- Distribution of weight load along the foundation contour.
There are many projects in the world, in the construction of which foundations installed on screw and concrete piles were used. Most of them are eco-projects whose function is to preserve the pristine beauty of the places chosen for construction. The protected corners of Norway and Finland were enriched with unusual buildings "on chicken legs". They not only became cozy dwellings for their owners, but also a tourist attraction for curious tourists.
Beautiful, comfortable, and most importantly, safe homes are striking in their simplicity and original design. What kind of piles and heads will become the basis of your home is up to you. The main thing is that this foundation has served more than one generation of your family.