How to make a foundation for a house extension with your own hands?


How to make a foundation for an extension to a house with your own hands?

The process of constructing a house addition can be thrilling, but it all begins with a solid foundation. It’s possible to save money and gain the satisfaction of doing the work yourself by laying the foundation. It’s an important step that needs to be carefully planned and carried out to guarantee your extension is sturdy and safe.

Knowing the fundamentals of foundation work is crucial whether you’re expanding your living area, adding a garage, or adding an additional room. There are various steps in the process, from material selection to site preparation to concrete pouring. You can confidently take on this task if you have the proper guidance and put in a little elbow grease.

We’ll lead you through each step of laying the foundation for your home addition in this guide. Everything you require to choose the best kind of foundation will be covered, including advice on how to steer clear of typical pitfalls. By the end, your project will have a strong foundation, both literally and figuratively.

Step Description
1. Plan and Design Measure the area and decide on the type of foundation. Consider soil type and load.
2. Excavate Dig a trench according to the foundation layout, ensuring proper depth and width.
3. Build Formwork Construct wooden or metal forms to shape the concrete. Ensure they are level and secure.
4. Reinforce Place steel rebar or mesh inside the forms to strengthen the concrete.
5. Pour Concrete Mix and pour concrete into the formwork, filling it evenly. Use a vibrator or tamp to remove air pockets.
6. Level and Cure Level the surface of the concrete and let it cure for at least 7 days before removing forms.

How to properly make a foundation for an extension

After researching the experience of building additions on different kinds of foundations, the builders concluded that it is preferable to work on foundations of the same kind. Different levels of shrinkage and the perception of soil reactions account for this. Distinctive operational, mechanical, and physical qualities may result in a breach of the structure’s integrity and extra expenses.

The following options for foundation connections are utilized:

  1. Hard. The connection is made using reinforcement bars, which are driven into the existing base and laid when pouring into a new. By welding the reinforcement into a single structure, we get a monolith. This type of connection guarantees the integrity of the building, especially when erected under one roof. Please note that a rigid connection is unacceptable on heaving soils prone to deformation.
  2. Flexible. Relative mobility is achieved due to the expansion joint between the bases. The gap filled with thermal insulation materials allows you to dampen the forces from heaving soils and reduce the likelihood of damage to integrity with different shrinkage.

Initial stage, preparing the tool

After determining the kind of foundation to be built, we move on to the project’s execution. You’ll need the following equipment and tools for these tasks:

  • pegs, cord for marking;

You can simply calculate the area and mark it yourself if you need the assistance of a specialist to decide on the type of future foundation.

  • building level;
  • shovels or an excavator to form a ditch;
  • crochet hook for tying reinforcement;
  • construction vibrator;
  • concrete mixer.

The work in preparation entails:

  1. Soil study at the site of future construction in order to determine the type of foundation suitable for these conditions.
  2. Determining the type and depth of the foundation of the existing building. If there is a screw foundation, the diameter and depth of the piles are determined.

How to make a foundation for an extension to a house using reinforcement

One can decide whether to combine the two foundations using a rigid method after the soil study is finished and the shrinkage of the existing building has been evaluated. You can construct a single structure that is resistant to deformation with the help of reinforcement. Recall that only hard soils free from seasonal heaving can support the foundation and other structural components of the building. Since strip foundations are the most popular type of foundation for small-scale construction, we will use them as an example to discuss the sequence of work.

There are various kinds of structures with varying construction technologies and strength attributes.

If you want to manually lay the groundwork for a house addition, follow these steps in order:

  1. Clear the surface from vegetation. Uproot trees and shrubs to avoid damaging the integrity of the foundation with roots.
  2. Mark the outline. Use a cord, pegs and a construction tool to control the angles, since it is difficult to mark the foundation of the extension without using it.
  3. Dig a trench of the calculated width. The depth is determined visually – it should not exceed the size of the existing foundation. Plan the walls and bottom of the trench.
  4. Carry out measures to secure the reinforcement bars in the existing foundation. Drill holes, hammer metal reinforcement into them. For more reliable fastening, make a cut at the end of the rod and insert a small insert, which will wedge the reinforcement when driven in.
  5. Install the formwork. Form a reinforcement frame inside, tie it to the prepared rods.
  6. Fill the formwork with concrete mortar.

Continue with additional construction after the concrete has fully set.

Extension to the house on screw piles

Even inexperienced builders can equip a screw foundation for a house addition with their own hands.

A pile foundation is composed of numerous piles, which are a particular kind of pillar with a screw-shaped tip. The piles are connected by cement mortar tape, though sometimes they are not.

The requirement for a professional soil assessment and the selection of piles with qualities appropriate for this kind of soil are the only details that need to be considered. It is best to leave the soil study to specialized organizations and then select the piles afterward. With a simple tool, pile installation can be completed independently. Benefits of using a screw base:

  • no need for excavation work. Given the current design of the site, this point is important;
  • relatively low cost of work. Explained by the possibility of installation without the use of hired labor;
  • speed of installation. If the area of ​​the attached room is small, the piles are installed within 24 hours;
  • time factor. When pouring concrete foundations, a long time passes before the construction of walls begins. Using piles, construction can begin immediately;
  • reusability. If the plans have changed and it is decided to move the extension, then the piles are unscrewed and installed in the required place.

Building a screw foundation on your own for an extension is not hard. Depending on the length of the pile and the complexity of the soil, installing one pile will take three people anywhere from fifteen to sixty minutes. Following screw installation, the trunks are concretized and then trimmed.

A shallow pile-screw strip foundation is thought to be the most cost-effective way to build a small addition to a home.

Do-it-yourself foundation for an extension to a house on slabs

In the following situations, setting up a slab foundation is recommended:

  1. High groundwater. Not rigidly connected to the main building, the slab has an increased shrinkage tolerance.
  2. Weak soils with reduced bearing capacity. Having an increased contact area, the concrete slab will prevent uneven subsidence of the building.

Because the slab foundation is different in thickness from the existing foundation, it is challenging to tie it firmly. It is preferable to use an expansion joint to divide it.

For stability and longevity, a solid foundation must be built when constructing a house addition. This post will walk you through the process of building a foundation on your own, from selecting the appropriate supplies to making sure the depth and leveling are correct. Even with no prior construction experience, you can confidently lay a solid foundation for your extension by following these simple instructions.

Foundation for an extension to a house made of foam blocks

Frequently, the completed building’s weight is different from the existing building’s weight. One type of porous building material is foam blocks. characterized by its low weight and lack of need for a strong base. Let’s investigate the correct way to construct a foam block foundation for an extension. It makes sense to forego a rigid connection and build a free-standing foundation in light of the variations in weight and, thus, the varying degrees of shrinkage of structures. Make use of a closed circuit. It will guarantee that the structure fits more snugly.

This material is lightweight and will place the least amount of strain on the soil.

Complete the task utilizing the developed technology.

  • mark the perimeter of the base using pegs and a cord. Control the size of the diagonals and the size of the angles. For a complex configuration, divide the outline into several rectangles and control the geometric dimensions of each element;
  • prepare a trench 30–40 cm wide. Fill the bottom with a sand and gravel mixture, tamp it down;
  • install the formwork. The part protruding above the ground surface must be tightly fitted to prevent the solution from leaking;
  • lay a waterproofing material in several layers along the perimeter of the existing foundation, which is an expansion joint. You can use roofing felt, mineral wool or boards treated with a special impregnation;
  • lay the reinforced frame in the prepared trench;
  • fill with concrete mixture. Let it stand until it hardens completely.

Frame extension to a wooden house

Forming the base when constructing a building is technologically similar to constructing a foundation for an addition to a wooden house. The immutable qualities are:

  • preparation of the trench;
  • formation of a wooden frame for concreting;
  • reinforcement with a spatial reinforcement frame;
  • pouring concrete mortar.

This choice is meant to make the construction process’ technological processes simpler.

The accurate joining of the extended foundation to the existing building’s base is the primary characteristic that sets it apart. Two foundations that should form a single power frame but were formed at different times must be kept intact. When adding a new capital foundation to a wooden house, the steps are taken in the following order:

  1. Provide access to the existing part of the wooden building foundation by removing soil to the required depth.
  2. Form a trench along the perimeter of the room being added, ensuring that the depth of the new and previously installed foundations corresponds.
  3. Clean the side surface of the previously installed base from the waterproofing coating.
  4. Drill a group of holes 6–8 cm deep in the joint area using a hammer drill, intended for installing fixing reinforcement rods.
  5. Tightly fix steel rods in the side surface, intended for tying the reinforcement frame of the new foundation.
  6. Install wooden formwork along the contour of the building, using panels knocked down from planed boards.
  7. Wash off dirt from the existing foundation with water under pressure.
  8. Assemble and securely fix the reinforcement cage, ensuring its fixation with the installed reinforcement.
  9. Pour concrete mortar made according to the traditional recipe.

When adding a new foundation to an already-existing wooden building, you need to wait for the concrete to completely harden. The concrete needs to be moistened and covered with plastic film on a regular basis. The base created with the aforementioned technology allows buildings made of different materials to be combined into a single structure.

Although it may seem difficult, laying the foundation for a house addition is a manageable project with proper planning and close attention to detail. You can construct a sturdy foundation for your new area by being familiar with the fundamentals of excavation, formwork, and concrete pouring.

Remember that making sure the leveling and drainage are correct is essential to a successful foundation. These elements are essential to your extension’s stability and longevity. It will save you trouble down the road if you take the time to properly prepare the ground.

Finally, if you have any questions about any step, don’t be afraid to seek professional advice. Although doing it yourself can be satisfying and economical, consulting a professional can help guarantee that your foundation complies with all applicable building codes and is safe. Your home extension will endure for many years if you take the proper precautions and have the necessary knowledge.

Video on the topic

Do-it-yourself formwork for the foundation of an extension

DIY foundation for an extension for 7 thousand rubles

Correct foundation for an extension. Epilogue.

Correct foundation for an extension

DIY extension foundation

An extension to the house so that it doesn’t move away.

Which aspect of concrete application are you most interested in?
Share to friends
Marina Petrova

Candidate of Technical Sciences and teacher of the Faculty of Construction. In my articles, I talk about the latest scientific discoveries and innovations in the field of cement and concrete technologies.

Rate author
StroyComfort1.com
Add a comment