How to Replace a Concrete Footing.

A concrete footing is a base that supports a structure, such as a house, a deck, a pergola, or a retaining wall. Concrete footings are usually poured into an excavated trench and reinforced with steel bars.

Sometimes, concrete footings may need to be replaced due to damage, deterioration, or changes in the design of the structure. Replacing a concrete footing can be a challenging and labor-intensive task, but with the right tools and techniques, it can be done successfully.

Here are the steps to follow:

1. Determine the size and location of the new footing. Before you start removing the old footing, you need to plan and mark the size and location of the new footing. You can use stakes and strings to outline the perimeter of the new footing. You also need to check the soil conditions and the bearing capacity of the ground to determine how deep and wide the new footing should be. You can consult a structural engineer or a building surveyor for guidance on this matter.

2. Remove the old footing. The next step is to remove the old footing from the ground. Depending on the size and shape of the old footing, you may need to use different methods to break it up and pull it out. For small post footings, you can dig around the perimeter of the footing until you reach the base, then move it back and forth until it becomes loose, and finally pull it out like a tree. For larger or irregular footings, you may need to use a jackhammer to break the concrete into smaller pieces that can be lifted out manually or with a machine. You should also remove any steel bars or other materials that are embedded in the old footing.

3. Prepare the trench for the new footing. Once you have removed the old footing, you need to prepare the trench for the new footing. You should dig until your trench is as deep as your plans require, then use a shovel or a rake to level and compact the bottom of the trench. You should also install drainage pipes or gravel at the bottom of the trench if needed to prevent water accumulation and frost heave.

4. Build and install the formwork for the new footing. The formwork is a temporary structure that holds the concrete in place until it hardens. You can use wooden boards, metal stakes, and nails to build and install the formwork along the perimeter of the trench. You should also use braces or supports to keep the formwork stable and level. You can use a spirit level or a laser level to check that the formwork is aligned correctly.

5. Place and tie the steel reinforcement for the new footing. The steel reinforcement is a network of steel bars or mesh that strengthens the concrete and prevents cracking. You can use steel bars of appropriate size and spacing according to your plans or specifications. You should also use wire ties or clips to connect and secure the steel bars together at intersections. You should also use plastic spacers or chairs to lift the steel bars off the bottom of the trench so that they are embedded in the middle of the concrete.

6. Pour and finish the concrete for the new footing. The final step is to pour and finish the concrete for the new footing. You can use ready-mix concrete or mix your own concrete using cement, sand, gravel, and water. You should also use additives or admixtures if needed to improve the workability, strength, or durability of the concrete. You can use a concrete mixer, a wheelbarrow, or a pump truck to transport and pour the concrete into the formwork. You should also use a shovel or a rake to spread and level the concrete evenly within the formwork. You should also use a vibrator or a rod to compact and remove air bubbles from the concrete. You should also use a trowel or a float to smooth and finish the surface of the concrete. You should also use an edger or a groover to create joints or grooves along the edges of the concrete.

7. Cure and remove the formwork for the new footing. The last step is to cure and remove the formwork for the new footing. Curing is the process of keeping the concrete moist and protected until it reaches its full strength. You can use water sprays, wet blankets, plastic sheets, or curing compounds to cure the concrete for at least seven days. You should also avoid loading or disturbing the concrete during this period. After curing, you can remove the formwork carefully by prying off the boards and pulling out the stakes. You should also dispose of the formwork and the old footing materials properly.

RECOMMENDED:- 

What are the advantages and disadvantages of combined footing and isolated footing?

I hope you found this article helpful. If you have any questions or feedback, please feel free to reach out to me. 😊