How to lay out a strip foundation for a house yourself

The first step in building a strong, long-lasting house is laying a solid foundation. The strip foundation is one of the most often used options for residential buildings. This kind of foundation is particularly well-liked because of how well it works to support the structure steadily and simply.

Although it may appear difficult, you can lay out a strip foundation on your own with the correct advice and a little perseverance. Learning the fundamentals of laying a strip foundation will help you get off to a good start, regardless of the size of the structure you intend to build.

You will be guided through the process of laying a strip foundation for your home by this article. We’ll go over each step in detail, from assembling the required equipment and supplies to laying out the location and pouring the concrete. You’ll know exactly how to lay a solid foundation for your new house by the time you finish.

1. The importance of correct foundation markings

Transferring the dimensions and axes of the planned structure from the drawing to the construction site is known as marking the foundation for a house.

With an incorrectly marked foundation, its walls will not form a rectangle, but a rhombus or trapezoid. It may not be visible to the eye, but when laying the slabs of the first floor – above the basement, they can collapse or hang at one of the corners. This situation will be noticeable. It will be much worse if there is not enough support area for the slab, and instead of 150 – 200 mm, 50 or 30 mm remain. The slab will lie in place, and then, after loading with screed, flooring, heat and sound insulation and their structural elements, furniture and residents, it can break off part of the wall and ..

Building a roof without right angles presents additional challenges. It will be extremely difficult, if not impossible, to mount the roof correctly and install rafters, let alone lay slate or tiles.

2. Requirements for the site. Reference to the terrain taking into account geodetic data (soil types, groundwater)

If at all possible, the construction site should be level and clear of shrubs and trees. If it slopes slightly, that will be advantageous.

The site’s contours, or the points that remain stationary throughout construction and are indicated on the plan, must be evident. A site must be marked on the ground if one of its edges crosses the "red line." On this line, there are multiple stakes you can win.

If at all feasible, you should drill multiple wells to ascertain the site’s soil properties, groundwater level, and chemical composition.

Drainage, or e. e. drainage, must be set up if the site’s groundwater is situated close to the surface and close to the foundation’s design level. In this instance, the water needs to be redirected between 0.7 and 1 m below the foundation’s bottom.

If you take the proper measures, installing a strip foundation for your home can be a simple do-it-yourself task. First, carefully consider how the foundation will be laid out in relation to the layout of your house and the site. Mark the outline with string and stakes, making sure that everything is square and level. After digging the trench to the necessary width and depth, erect a formwork to retain the concrete in place. You can build a sturdy, long-lasting foundation for your house with these fundamentals.

3. Tools and materials for marking

Marking instruments consist of:

1. Roulette. Preferably metal, at least 10 m long, preferably 20 m. Fabric is lighter and a little more comfortable, but it sags and reduces accuracy.
2. Laser level for marking the foundation, its height, horizontal, etc. works.
3. A water level, also known as a flexible level or hydraulic level, is a long flexible tube with transparent glass or plastic sighting tubes at both ends, on which divisions are applied exactly every 1 mm and each of them is closed with a stopper. This device operates according to Pascal"s law for communicating vessels. Flexible tube length 12 meters or more. The tube is filled with water so that it is located approximately in the middle of the sighting tubes.
4. Thin strong rope (twine), cord. You can use thin wire, but it is not very convenient to work with.
5. Markers, pencil, paper, multiplication table, formulas.
6. Hammer, nails.
7. Material for making cast-offs – wooden stakes – at least 16 pcs. and bars – 8 pcs. Sometimes 8 pcs are used. U-shaped pieces of steel reinforcement that are driven into the ground.

4. Brief description of the laser level

Among the many tools in the vast category of measuring tools is the laser level.

The primary function of a level is to measure the elevation differential between two points on the surface and to create vertical, horizontal, and any intermediate planes in the shape of a line, which is a laser beam trace. Such a device can also create point projections, which project a point onto the surface.

Self-leveling cross levels, which construct two perpendicular planes—horizontal and vertical—are most frequently utilized. They can be installed in any direction and rotated. Auto-leveling elements are continuously adjusting the horizontal plane.

The following are the primary features of laser leveling:

• measurement accuracy, professional devices give an error of up to 3 mm at 10 m, and household ones up to 0.5 mm at a distance of 1 meter;
• measurement range: for households up to 10 m, professional – 30 m or more;
• the number of designed planes is usually two or more, etc. P.

However, a level is first and foremost a tool for measurement.

It won’t be very helpful to you unless you know how to use it properly.

If you are using it temporarily, like for rent, don’t expect it to function by itself.

Do not rent the device if you do not know what an adjustment is.

Before using it, make sure all the features listed in his passport are accurate, the measurements are accurate, the settings are correct, etc. The device description contains all verification procedures.

There isn’t any foundation-laying task that can’t be completed with a level. Therefore, it can be easily replaced with an ordinary water level when used correctly. While work on a construction site is sped up and made simpler with a laser level.

5. How a strip foundation works and its advantages

The reason for its name, "strip," is that it resembles reinforced concrete strips placed in a trench dug around the building’s outline. A pit is dug out and all foundation work is done there if the soil is collapsing, the laying is deep, and there are numerous intermediate walls inside the building’s perimeter that require foundation construction as well.

The strip foundation may be monolithic or prefabricated monolithic in structure. In the latter scenario, its upper portion—which is made up of individual blocks—will resemble a monolithic belt of reinforced concrete that is positioned along each of the foundation’s walls.

Trenches for a strip foundation can be dug manually during private construction to save costs. In this instance, the ground is made level by either removing the soil or spreading it around.

Usually, the amount of soil freezing determines the strip foundation’s depth. It is slightly more than a meter in the southern parts of Russia, 1.5 to 2 meters or more in the northern parts and Siberia.

Benefits of using strip foundations:

• simple construction technology;
• it is possible to lay a ground or basement floor;
• built on strong soils – stone-sand and clay;
• they are quite economical;
• parameters – width, depth, amount of reinforcement, etc. indicators affecting strength are easily adjustable.

Such a foundation for a house is something you can construct by hand.

6. Marking axes and angles – placing benchmarks outside the perimeter of the foundation

Every marking should begin at a location on the ground that is exactly "tied" to the site plan. This is typically a corner that is connected to the so-called "red line," which is the line separating your property from public land that is off-limits to building. Such a point will be found at the intersection of the "red line" and the borders of your and the nearby plot. Your site’s fence should face inward from the red line.

The house is normally situated at the following distances from both this fence and the neighbor’s fence:

• according to sanitary standards defined by SNiP 30-02-97, p. 6.7: at least 3 m;
• according to fire safety standards SP 42.13330.2011p.7.1: at least 6 m from the windows to the walls of a neighbor’s house or garage, bathhouse, barn, etc., at least 3 m – from a residential building to the border of the neighboring plot.

As a result, you must withdraw to the designated distance or farther before you can begin using your hands to mark the foundation.

A. Placed in the designated "Red Line" area. It is preferable to hire a professional landing specialist to mark the future corners of the house if the owner plans to build it precisely at a normalized distance from the Red Line. However, most of the time, move back 1 to 1.5 meters from these constraints.

Precise alignment with the cardinal. At a considerable distance from the "red line," it is feasible. but typically pay attention to the roads’ axial line.

When excavating the trench, the marking pegs will undoubtedly fall into it if you use pegs to mark the foundation’s corners and clog them precisely at the locations of the house’s future corners.

Thus, the first step in designating the foundation site is the installation of wooden frames outside the trench or pit—that is, outside the excavator’s working area. We refer to them as waste boards, waste beams, or just cast-offs. They’re called "benches" by some "experts". They have wires or cords pulled over them. The required marking points will be provided by the intersections of the cords, but they will be "hanging" in the air rather than on the ground. Later, these "points" are moved to the formwork or the ground.

The top bar of the cast-off has three or five nail marks hammered into it:

• in the center – an axial mark for the axis of the foundation wall;
• to the right and left of the axial line are marks for the width of the foundation wall;
• even further – the width of the pillow under the foundation.

Step 1. Marking the starting side.

Starting from the side closest to the "red line," we move forward.

From any corner, we pound two cast-offs outward by one to two meters. Grab the axle cord. Set the upper portion of the cast-off bars to a height of "0" using a water level. After retreating one to one and a half meters, we establish a starting point by driving the first peg into the ground. From there, we "raise" the point onto the cord using a plumb line. We mark the length of the wall that we measure along the cord’s axes. Hammer in the second peg after lowering the point to the floor. The first wall’s axis is located in between the pegs.

Step 2. Marking the side perpendicular to the initial one.

Using the Pythagorean theorem and knowing the lengths of the sides of the foundation, we calculate the length of its diagonal (along the axes). On the cast-off of the perpendicular side, on the axial nail we fasten the end of the cord and pull it over the opposite cast-off. From the intersection with the axial cord, measure the length along the axes of the second side and make a mark on the axle cord of the second side. On a free piece of cord we tie knots along the diagonal length along the axes. We fix one knot on the axis mark of the third side and pull the second knot towards the opposite wear of the second side. By aligning the second knot with the mark on the cord of the second side and pulling the cords, we get the first right angle.

An additional method for creating a right angle is the "Egyptian triangle" approach. Measure 4 meters, or a multiple of this value, from the first axis’s intersection with the second axis on the cord. We measure 3 m or an equivalent multiple of the distance on the second axis cord. We use a tape measure to measure the distance between the marks we make on the cords. It ought to be five meters. We obtain the precise value of 5 meters by shifting the second cord in relation to the first’s point of intersection. In this instance, the angle will be straight.

Step 3. We perform these operations two more times and get two more right angles.

The final actions need to occur in the zone of one point, which is the foundation’s virtual corner across from the first corner. The final two nodes should coincide if all measurements were taken with care and the computations were performed precisely.

Step 4. Checking the squareness of the markings.

We know from geometry class that a square or rectangle has equal diagonals on both sides. As a result, the check is performed by comparing the two diagonals’ measured lengths.

A few centimeters’ difference is acceptable. The foundation axes have been fully marked.

Step 5. Marking the edges of walls and pillows. We retreat the required distances from the axial mark, drive marking nails into the edge block and pull the cords along the boundaries of the walls.

Once the entire network’s virtual layout in the plan—that is, in a horizontal plane—has been verified as accurate, you can begin using an excavator to remove the dirt.

6.1. Permissible errors when marking foundations

Errors typically mount up. As a result, you must begin with the highest level of initial marking accuracy. A typical house’s foundation diagonals should only differ by 3 to 5 centimeters. You did a great job if you could obtain a 2 cm difference.

If it is between one and two centimeters, you can proceed with caution and markings. If it measures between 3 and 4 cm, you have gone beyond what is allowed. You must measure each segment’s length and make any necessary adjustments up until the final surgery if it is five centimeters or greater. Examine each node and corner once more. Next, make another check of the diagonals.

Step	Description
1. Plan	Determine the location and size of the foundation based on your house plans. Mark the layout on the ground using stakes and string.
2. Digging	Excavate the trench where the foundation will be laid. Ensure the trench is wide and deep enough to accommodate the foundation and footing.
3. Formwork	Build wooden forms to shape the foundation. The forms should be securely placed to hold the concrete in shape.
4. Reinforcement	Place steel rebar or mesh inside the trench to provide strength and support to the foundation.
5. Pouring Concrete	Mix and pour concrete into the forms. Ensure it is evenly distributed and fills all gaps.
6. Curing	Allow the concrete to cure properly. Keep it moist for a few days to ensure it sets and gains strength.
7. Removing Forms	After the concrete has fully cured, carefully remove the wooden forms.
8. Backfilling	Fill the trench around the foundation with soil and compact it to support the structure.

Although it takes careful planning and execution, installing a strip foundation for your home can be a rewarding do-it-yourself project. Mark the perimeter of the foundation precisely and make sure your measurements are accurate first. This will guarantee a strong foundation for your house and help you avoid expensive errors.

The next important step is to dig the trench once your layout has been marked. Ensure that the trench is sufficiently wide and level to support your foundation. To ensure evenness, use a spirit level, and keep the depth constant all the way through.

It’s time to erect the formwork and add steel rebar for reinforcement after excavation. In order to guarantee the durability and strength of your foundation, proper reinforcement is essential. To create a level surface, carefully pour the concrete and smooth it out. Give the concrete time to cure completely before starting any additional construction.

You can build a strong foundation that will support the structure of your home by following these steps. Go slowly through each step of the process, and don’t be afraid to ask for assistance if you need it. Your building project will have a solid base and greater success overall with a well-laid strip foundation.

Video on the topic

The easiest way to mark a foundation 👍👍👍, it couldn’t be easier

Do-it-yourself shallow strip foundation.

How to CORRECTLY mark the foundation WITH YOUR HANDS? / The simplest ways to mark a foundation!

To what depth should a strip foundation be poured? Depth of a strip foundation for a two-story house