Before starting excavation work during the construction of the foundations of the building, it is necessary to prepare the site. To do this, you need to know how to properly lay out the foundation for a private home with your own hands. A drawing or sketch must be transferred to the area and this must be done with high accuracy in order to avoid problems during further construction.
Why markup
Many non-professional builders do not understand the importance of preparatory work. Below are the problems that may arise if the markup is not correct or completely neglected:
- violation of the geometric dimensions of the building;
- inaccuracies in angular dimensions;
- incorrect operation of load-bearing structures due to deviations of foundations and walls from design;
- when using prefabricated ceilings, their elements manufactured according to design values may not fit the existing sizes, which will lead to additional financial and labor costs.
Marking the foundation contour under the house allows you to position the supporting structures in strict accordance with the decision.
The location of future walls of the building and the size of the premises depend on the location of the foundations.
Necessary tools
In order for the marking under the foundation to be accurate and fast in execution, it is necessary to stock up on the following devices and materials:
- tape measure with a long measuring tape (ideally equal to or greater than the length of the longest wall of the house);
- wooden pegs or reinforcing bars (the choice depends on the materials available and the density of the base soil);
- construction square (has angles with values of 30.60 and 90 degrees);
- strong cord;
- wooden slats;
- clamps, clothespins or nails to secure the cord to the pegs;
- construction level (you can get an inexpensive bubble, laser will greatly facilitate the work, but has a high cost).
If possible, you can also use the level, but its purchase for the construction of one building is impractical. You also need to have scissors for cutting the cord, a hammer for hammering nails, a calculator for the necessary calculations.
Beginning of work
As a general method, we can mark the strip foundation. Removal of tape or individual supports (poles, piles) to the terrain. It differs insignificantly. The easiest way is to mark the ground under the slab foundation. It is enough to indicate the angles and sides of the plate.
They begin preparing the site for construction by finding the first point. Any corner of the house can serve it. For strip and other types of foundation, you will need to find the outside of the corner. When making drawings or sketches, it is recommended that the object under construction be tied to existing ones or the boundaries of the site.
Having determined the first point, you need to build a right angle. The easiest way to do this is with the Egyptian Triangle method. First you need to note the angle with a small length of the sides, using the construction angle. Then, in one direction, the value is divisible by 3 (it is convenient to postpone 3 or 6 meters, such a large length will reduce the measurement error), and in the other direction, divisible by 4 (if in the previous case 3 meters are delayed, then you should take the side length of 4 meters, and if 6 meters, then - 8).
After check the correspondence of the angle to the value of 90 degrees. To do this, you need to measure the distance between the ends of the delayed segments along the shortest path. If segments of 3 and 4 meters were used, then the length of the diagonal should be 5 meters. If the segments were 6 and 8 meters, then the diagonal with evenness of the angle will be 10 meters. If the values do not match, you must align the angle to meet the condition.
To perform the job correctly, you must also clearly represent the layout of the markup.
Marking or casting consists of wooden pegs and nails attached to them. This design is created only by the outer contour of the strip foundation.
The inner borders of the outer tape and the inner walls are marked with a cord, which is nailed to the nail on the nails. The outer cast-out of wood can be performed both solid and with gaps.
After finding the first corner, the work on marking the strip foundation of a simple rectangular section is carried out in the following order:
- Finding the second and third points by deferring the lengths of the walls. Construction of 90 углов angles from these points and their verification. At each point, landmarks are forgotten.
- Finding the last fourth point and completing the construction of the contour of the building. Checking the angle.
- Checking the diagonals. They must match the drawing. If the house, as in the case under consideration, is rectangular in plan, the diagonals should be equal. The same rule applies to the square.
- Pegging on the outer perimeter, pulling the cord.
- Nailing to the pegs of horizontal rails. You need to do this approximately at the middle of the height of the vertical stand or along its upper edge.
- Next, perform the marking of the inner contour. To do this, they retreat from the outside to the width of the foundation and are also indicated with pegs and a cord (rail).
- Checking the internal angles and diagonals.
- Marking the internal walls and checking the angles of their interface with the external.
After marking is completed, the top layer of fertile soil is removed from the area under the house and a trench is dug. When arranging a strip foundation for a building with a basement, instead of a trench, it is necessary to make a foundation pit. The device of the internal part of the marking in this case is not required before the start of soil development. The cord for marking the inner border is pulled after excavation work, attaching it to the external rails at the required distance.
DIY marking the foundation does not require complicated equipment. But if a rather large construction is planned, to reduce labor costs a level (laser level) will be required. With its help, all the necessary geometric measurements, including checking the angles, can be carried out in the shortest possible time. For private housing construction, the simplest devices are enough.
So that the strip foundation foundation does not interfere with the excavation, it will be correctly performed with an indent of 50 cm to the outside of the design values.
For stand-alone foundations, as well as for strip foundations, an external cast is first performed, and then a cord is pulled to indicate the supports.
If you carry out the marking correctly, during the construction of the building there will not be strong deviations from the design values (provided that the installation technology of the walls and their evenness are observed). Pouring and marking for the foundation will allow you to build a house without additional measures to fit the elements of the house to the available dimensions.