A strong foundation holds a house above ground, keeps out moisture and insulates against the cold. It also resists movement of the earth around it. When it comes to building a house, the starting point is building strong foundations and these strong foundations will safely distribute the weight of your new home and prevent the subsoil from spreading.
Mistakes at this stage could prove costly so it’s vital to double-check all measurements, mark them on the plans and make sure everyone is working from the same set of plans, and be prepared to be flexible if the excavation process reveals some surprising ground conditions (setting aside a healthy contingency budget is essential for this stage). If you aren’t sure which foundation system to choose or what type of soil you’re dealing with, and then make sure you take a look at our guide to foundation system and soil types. Then, whether you’re project managing, taking on some of the work yourself, or want to have an overview of what your builder is about to do.
Here is a step-by-step guide for laying out your building foundations:
Site selection – Selecting the site for building your new home is the first important step to build a strong foundation. At first, finalize the plot area based on your requirement, location of the plot, and the ground condition of the plot (not prone to frequent waterlogging). Always investigate the soil condition of the land parcel, and many times it requires special foundation/treatment as the soil may not have desired load carrying capacity or may have some adverse properties. This can weaken the building foundation in the long term. In this scenario, you need to consult with a Geotechnical Consultant / Structural Engineer for the right solution to your building foundation.
Obtain any necessary permits and permissions – The second step involves checking with your local regulation committee to find out what kind of permits are required in your area. Typically, you’ll need a construction permit if you’re building a new home. Some regions may also require a permit for a shed. If you live in a community with a home owner’s association (HOA), you may need their approval too. It can take weeks or months to get the necessary permits, so plan the project well in advance.
Excavation work – It is the next important step to build the foundation of your home. Carry out proper surveying of your land to obtain a layout plan on the ground-based on the approved drawing. Mark all pillars, trench excavation lines concerning the center lines of walls. Ensure that excavation is done by the Contractor as much as it needed and true to levels, alignment, shape, and size, and in this context, you may appoint a Contractor for carrying out the excavation of the Foundation of your building after checking the credentials of similar works.
Anti-termite treatment – This is an important step to protect your building and foundation from the termite attack, and the soil around the foundation needs to be treated up to the plinth level with appropriate chemicals, and the anti-termite treatment of being a specialized job should be executed through a specialized agency only. The specialized agency should be a member of the Indian Pest Control Association.
In the foundation site, remove all soil, rocks, and roots – Most regions have rules regarding the depth of the concrete foundation for homes and other structures. To determine how thick the concrete must be, check your local laws. Account for adding a base layer of 4–12 inches (10–30 cm) of crushed stone, depending on the type of structure you’re building.
Pour crushed stone into the excavated area – Using crushed stone on top of the soil creates a sturdier base for the concrete, and for smaller projects, like a shed, use 4–6 inches (10–15 cm) of stone. If you’re creating a foundation for building a house, pour 10–12 inches (25–30 cm) of crushed stone into the excavated site.
Wooden Formwork – The next step of building a house is the Wooden Formwork. The Formwork should be made as per the size of the Footing and sufficiently rigid so that there should not be any displacement while placing reinforcement bars and laying & compacting of the concrete. The gap between the Formwork should be sealed properly to prevent any loss of slurry from the concrete.
Make sure the re-bar is not too close to the soil – Rebar (reinforced steel bars) are placed inside a block of concrete. The concrete should at least be more than 4 inches thick at the base when you place the rebar in it. This creates some distance between the ground and the steel inside the concrete, and if your rebar is nearer to the ground, it is at risk of rusting. Once rust creeps into the rebar, it can spread throughout the rebar system and make the foundation weak, and they provide high strength and ductility to the constructed structure which comes different sizes including 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, and 25mm.
Pour concrete into the footing – This is the final important step of building a strong foundation for your home. As per the approved design grade, the concrete should be selected. For the quality check, the workability of the concrete to be checked periodically during the process of concreting work. Take concrete test cubes of required numbers to check the crushing strength of the test cubes, and the concrete should be compacted well into place and cured adequately. Curing should start early and continue for a sufficient period to ensure that it develops the desired strength and does not crack.
All these steps are essential for building a strong foundation for your new home. Any mistakes you make in the foundation can’t be changed in an entire lifespan of your home.