How to pour a foundation

Mr. HowToSpecialist December 24, 2011 Comments Off
How to pour a foundation

This article is about how to pour a foundation. Generally speaking, the foundation is the most important element when building a house, as it will support the weight of the walls, roof and the rest of the structure. Therefore, you have to pay attention when poring the foundation, as to make sure the footings have the proper depth and the reinforcement structure observes the plans. When building the house foundation, there are several aspects you have to take into consideration, as to make sure your home will be durable, either you construct a wooden or a brick house.


Before pouring the foundation, you have to decide weather you are going to build the walls over a concrete slab, or you are prepared to invest in a basement. Usually, this is a tough decision, as it has its advantages and disadvantages: it will give you extra space (storage space, or you can use it for setting up a gym, recreation room) but it comes at a higher price (you have to use more reinforcing bars, excavate in the ground and transport the soil, pour a lot more concrete).

Secondly, you have to dig a  foundation, using the best techniques, as to deposit the excavated soil properly and get the job done in a short amount of time. Next, you have to build the reinforcing structure (according to foundation plans) and build the form for the concrete foundation. These steps are very important for pouring a foundation, as you have to make sure it is on the proper location and the trenches have the right depth and width. Remember that you have to hire a qualified professional  as to supervise the workers during the construction of your house.

Install a rigid structure of rebars to reinforce the concrete foundation. The amount and the complexity of the rebar structure should be determined by a qualified engineer, especially if you build a house.  In addition, don’t forget to install anchor bolts in the foundation, to secure the wooden wall. Nevertheless, if you will construct brick walls, you shouldn’t install the anchor bolts, but build concrete pillars at the intersection of the walls. Study thoroughly your local codes to determine the number and the location of the anchor bolts, as well as the reinforcement structure. During the construction of your house the inspectors will stop by to check if you comply with the local codes, therefore make sure you are prepared.

 

In order to pour a foundation, you need the following:

Materials:

  • 1×4 wood boards for building the formwork / tego plywood boards
  • nails/wood screws to fasten the formwork
  • concrete
  • concrete pump to pour the concrete from the trucks

Tools:

  • safety gloves, glasses
  • measuring tape, carpentry pencil, l-square
  • circular saw/jigsaw to build the formwork
  • hammer

Tips:

  • use boots, as not to get your cloths and skin dirty with concrete
  • clean thoroughly your tools after you have finished the project
  • wear protective glasses and gloves, to avoid possible injuries
  • inset anchor bolts in the concrete, to tie the seal plate (for houses with wooden structure)

Time

  • few hours up to a day, according to the surface of your foundation and the number of workers

 

Pouring a foundation

Formwork for foundation

Formwork for foundation

Before showing you how to pour a foundation, we have to highlight the importance of building a proper formwork. Therefore, make sure you follow the guidelines from the foundation plans. Use 2×10 boards to build the forms.

Smart tips: measure the diagonals of the foundation, as to make sure your corners will be right angled. In addition, use the well-known 3-4-5 rule for better precision. You can read more about how to build a formwork, in our article.

Footings reinforcement structure

Footings reinforcement structure

Next, you have to check if the formwork is rigid and well locked into position, otherwise the concrete will move it and misalign your foundation. In addition, make sure the reinforcing structure is set properly, before pouring the concrete.

Smart tip: calculate the quantity of concrete you need, before ordering it  to your local station. If the truck cannot pour the concrete directly into the footings, you have to rent a concrete pump. In addition, make sure they will give you a vibrator for concrete.

Pouring concrete in the formwork

Pouring concrete in the formwork

When pouring the foundation, you have to start from the  farthest point, as to make sure you won’t dirty the hoses or your cloths. Nevertheless, make sure you wear protective gloves and safety glasses, as to avoid pouring concrete on your skin (it is very irritating).

Work with patience, until you finish pouring concrete in the formwork. You have to understand that pouring concrete in foundation with hoses, is a tough job, as they are quite heavy. That is why, we recommend you to hire qualified professionals, if you aren’t ready to undertake the project by yourself.

Smart tip:  remember to insert the plumbing and water pipes in the foundation, before pouring the concrete. This is the proper way you should build the foundation, otherwise you have to break the concrete, which in turn will affect the rigidity of the foundation. Therefore, just remember to install the water and plumbing pipes before is too late.

Pouring a foundation

Pouring a foundation

After we had poured concrete in the formwork, our foundation looked like in the image. It might seam messy, but this is how things happen when building a house.  You just have to make sure you don’t waste a lot of material, as it is expensive and hard to remove after it dries out.

Smart tip: while a worker pours the foundation, another one has to vibrate the concrete, as to ensure there won’t be any air pockets left in the foundation.

Vibrating the foundation

Vibrating the foundation

In this image you can take a closer look on the process of vibrating the concrete. Consequently, you should sink the head of the vibrator in the foundation trenches for several minutes, until the concrete sets in the formwork. It is hard to describe the procedure in words, but you will get the idea once you try it for yourself.

Smart tip: you should vibrate the whole foundation, as to get the job done in a professional manner.

 

Filling the foundation with soil and gravel

Removing the foundation formwork

Removing the foundation formwork

After you have finished pouring the foundation and vibrating the concrete, you have to let the concrete dry out for several days. Next, you have to remove the interior form and prepare the foundation for pouring the concrete slab.

 

Smart tip:  if you are going to build a house on a wooden structure, you have to insert anchor bolts in the foundation,  to secure the walls to the concrete slab.

Filling the foundation with soil

Filling the foundation with soil

Next, we have to fill the foundation with soil and a thick layer of gravel mixed with a little sand (about 3”/8 cm). Therefore, you could use the soil you have previously excavated from the foundation.

 

In order to transport the soil back in the foundation, you have to use a wheelbarrow. After you have  filled the foundation with soil you have to tread it properly. In order to do this operation in a professional manner, you could use a plate compactor.

 

Next, you have to lay the gravel mixed with sand over the soil. This layer will make sure the moisture won’t affect the foundation, on the long run.

Installing extruded polystyrene under concrete slab

Installing extruded polystyrene under concrete slab

Next, after you have laid the gravel layer, you have to install anti-vapour barrier, as to make sure the water and moisture won’t damage your foundation. In the image, you can see that we have  also used 4×8  extruded polystyrene boards under the anti-vapour board.

Installing  extruded polystyrene  under concrete slab is a modern technique which increases your home insulation, both during winter and summer.

 

Pouring the concrete slab

Pouring concrete with hose

Pouring concrete with hoses

Next, you have to install the reinforcing net over the anti-moisture barrier, as to pour the concrete slab. Make sure you follow the guidelines from your structural plans, otherwise you won’t build a proper foundation. In order to pour the foundation, you also have to start with the farthest point, as to make sure you don’t dirty the hoses with concrete.  If the concrete trucks have access to your construction site, then you can pour the concrete directly from the trucks. You have to use large shovels to distribute the concrete evenly on the whole surface of the foundation, that is why we recommend you to hire several workers. Pouring a foundation is a complex operation and once you have started it you have to finish within several hours,  otherwise you wasted a great amount of money and materials.

Smart tip:  wear rubber boots  to avoid getting dirty with concrete. In addition, make sure you you don’t pour concrete in the plumbing pipes. The best solution is to tie a plastic bag at the end of the pipes, by using duct tape.

Finishing concrete slab

Finishing concrete slab

Next, you have to finish the concrete slab by using a bull-float. You can either buy the float, or make one from a wooden board and a stick.

 

Smart tip: it is almost impossible to level the foundation perfectly, but it is easy to give it a nice appearance. If you use the concrete vibrator, the concrete will level itself to a large extent. Nevertheless, you have to use the bull-float to give a nice appearance to the foundation.

Constructing concrete ceiling

Constructing concrete ceiling

Last but not least, you have to let the foundation dry, before you can start building the walls. Nevertheless, you have to remember that during hot summer days, you have to sprinkle water over the foundation, otherwise the concrete will crack. Read more about brick house construction.

Smart tip: you have to supervise closely the foundation for a couple of weeks, as to make sure everything is right. Remember to sprinkle water over the foundation, especially if the temperatures are above 77 ºF/25 ºC.

 

Thank you for reading our article on how to pour a foundation, and we recommend you to check the rest of our projects. If you have enjoyed this project, share it with your friends, by using the social media widgets.

Related projects: 

How to build a formwork

How to pour a concrete ceiling

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