Here’s the Scoop on How Contractors Pour Concrete Foundations

C.E. Larusso
Written by C.E. Larusso
Updated January 20, 2022
Suburban home with concrete driveway and green siding
Photo: hikesterson / iStock / Getty Images

Highlights

  • Before pouring a concrete foundation, ensure your contractor has the correct permits.

  • Depending on the climate and curing time, a foundation takes two to six weeks to complete.

  • To prevent moisture damage, your contractor must correctly waterproof your foundation with rubber elastomeric and drainage tile.

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Every great house starts with a strong foundation. There are a few essential steps to take to pour foundation correctly. It's crucial that you choose the right concrete, waterproof the foundation, and obtain the proper permits. Whether you build the foundation yourself or hire a contractor, it's wise to learn the ins and outs of the job so you can trust in your home's stability.

How Do Contractors Pour Solid Concrete Foundations?

Read on to learn the critical steps required to pour a foundation correctly.

Site Clearing

Contractors must clear the site before they start digging. They need to remove any trees, underbrush, shrubs, stumps, or large rocks, as well as any pieces left from the former construction. After clearing the site, the contractors will mark the area to be dug, or excavated, using wooden pegs and string.

Breaking the Ground

Now that they've marked the area, an excavator will dig into the ground, creating a hole that's larger than the planned foundation, with at least two extra feet on all sides. Workers will build forms for the foundation's footings, which are wooden frames used to hold the concrete in a particular shape when poured. Anywhere from 16- to 20-inch-wide footings are enough to handle the weight of a typical home. If you live on particularly volatile ground or your home is very expansive, you may need larger footings and forms.

Pouring Time

Workers leveling concrete foundation
Photo: LivingImages / E+ / Getty Images

Now that the space is clear, concrete is poured into troughs to keep it contained; it should take three to 10 days to cure. Once cured, contractors will strip off the forms. 

Waterproofing and Insulating 

Next, the contractors will waterproof the wall by adding a sticky substance—rubber elastomeric—to the foundation. This substance retracts water so it can't seep into your walls or foundation and cause damage. Next, contractors will add insulation. Finally, for extra security against moisture, drainage tile (perforated plastic piping) is added. Also known as "weeping tile," it draws water away from the foundation.

Tips for Successfully Pouring a Foundation

Now that you understand the steps of pouring a foundation, here are some tips to prevent mishaps.

1. Determine the Depth 

Before you dig a foundation, you'll have a piece of land and a vision of how you'd like your home to look. But before you start pulling up earth, you should determine how deep a foundation is required. On level ground with good soil conditions, three feet is a good estimate. For high-moisture soil or homes built on hillsides, you'll need more. Consult a professional contractor or structural engineer to determine exactly how much.

2. Obtain Proper Permits

You or your contractor must obtain the proper local building permits. Otherwise, your municipality could give you the bad news—long after pouring the foundation—that you need to make some major changes to your house. Always obtain the proper paperwork. The cost of your permits should be factored in when determining the total cost to build your foundation (typically $4 to $25 per square foot).

3. Use the Correct Mix of Concrete

You and your contractor must do some homework before selecting the right concrete mix. Not enough water or too much in the mix can cause it to dry too quickly or not quickly enough, which could cause the foundation to settle and crack. Keep in mind that local humidity also affects the drying time. High-strength concrete mix is the most popular choice for foundations, as it has exceptional durability.

4. Be Patient

As noted, your foundation is a critical component of your home’s construction. It may take two to six weeks to build, and will likely be the part of your home that takes the longest to get in place, but Rome wasn’t built in a day, right?

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