Learn what it takes to properly prepare for pouring new concrete.
To make sure your new concrete stays in good shape throughout its long life, proper site preparation is crucial.
Effective site preparation addresses critical factors such as drainage, soil conditions, and grading, which help prevent things like settling and cracking down the line.
Here at A-1 Concrete Leveling, we’ve been lifting settled concrete for over 30 years, and a majority of those cases of settled concrete have been caused by improper site prep practices.
For that reason, we’ve created this resource to explain what needs to be done before installing concrete to make sure your new concrete stays in place and in good shape over the course of its life.
Pre-Construction Prep Considerations
Concrete is usually installed near buildings, like a driveway next to a house or a sidewalk outside a storefront.
But before this construction on the nearby building begins, and before work is even started on the concrete, it's essential to evaluate several factors around the building site to ensure the future concrete stays in good condition.
Note: In this article, we focus mostly on houses, but the same ideas apply to all buildings.
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Grading
It’s important to understand how water will flow around the property, as water is concrete’s biggest enemy – it causes erosion, settling, surface damage, etc.
This includes considering the natural slope of the land and the impact of neighboring properties. For instance, if your house is built on a hill, assess how the lot's size and shape will affect water runoff toward your concrete.
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Fill Dirt
How much fill dirt your concrete is placed on top of will impact future settling. Because fill dirt is loosened up and often not properly compacted, it will settle over time, bringing the concrete on top with it.
This is especially true in homes with walkout basements built on what were originally flat lots – all of the fill dirt needed around the foundation will eventually settle over time.
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Water Flow Management
Proper planning during the building process is crucial for waterflow management.
Creating drainage solutions that fit the site is important to avoid water damage over time, like settling, flooding, pooling water, mold, and more.
For example, installing a drain across the front of a garage for a driveway sloped toward the home can prevent water accumulation and damage. Strategically running pipes under your concrete and through your yard to funnel water out away from your home and concrete surfaces can help with this, too.
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Gutter and Downspout Planning
Proper gutter and downspout planning during construction is also a vital part of managing your water.
Undersized gutters can lead to overflow, causing water to settle around concrete structures. Plan for worst-case scenarios rather than the bare minimum when planning for gutters and downspouts to ensure proper water management.
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Concrete Placement and Function
Plan where the concrete will go, what you want it to do, and how much space it will take up. For example, deciding between a ramp or steps can affect both the usability and appearance of the area.
Ensure there is enough physical space for the application and plan the positioning carefully to avoid awkward step heights, slopes that could cause drainage issues, or placing concrete where all the water will eventually run off.
How To Prep for Installation
After the building construction is complete, it’s time to install your new concrete. However, there are many things to consider before the pour:
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Proper Depth and Base Preparation
Using the proper excavation depth and base material is critical for long-lasting concrete. Be sure to dig deep enough to create a solid foundation. Typically, a 2-4 inch rock base is recommended, but deeper excavation may be necessary if the site is built on fill dirt.
For areas with clay soils that expand and contract with moisture, deeper excavation can help minimize the impact of soil movement on the concrete.
Pro Tip: A stone base is beneficial for its strength, and it also helps allow water to fall away from the bottom surface of the concrete, which helps minimize water damage to the slab.
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Creating a Level Surface
Ensure the concrete is installed on a level surface. This is necessary to achieve a consistent slab thickness, which helps prevent weak points and cracks.
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Proper Compaction
Proper soil compaction is crucial. If backfilling is required, compact the soil in layers.
Techniques like overfilling and applying excess weight can help compact the soil. Alternatively, allow the soil to settle naturally over time before laying the concrete.
Pro Tip: Many people choose to install a temporary gravel driveway while they wait for their soil to settle naturally. Then, they install a concrete driveway on this naturally compacted soil base.
Post-Install Tips
After the concrete is poured and cured, ongoing maintenance is essential to ensure it stays in good shape throughout its lifetime:
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Maintain Drainage
Continuously manage drainage around the concrete. Check to make sure downspouts are pointed and away and draining far from the concrete slabs, and ensure gutters are not overflowing.
Keep soil levels built up to grade away from the concrete to prevent water from pooling or running under the slab, which can cause erosion or settling.
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Make Adjustments Over Time
Be prepared to make adjustments as the landscape around your home changes. Adding soil around the concrete or nearby flower beds is often necessary to maintain proper drainage and prevent erosion.
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Keep Up With Regular Maintenance
Cleaning dirt and grime off the surface, sealing the concrete with a high-quality sealer, caulking gaps and cracks, and filling voids under the surface are all regular maintenance practices to help keep your concrete in good condition.
Proper Concrete Site Prep
Proper site preparation for new concrete involves careful planning and attention to detail. Making a game plan before construction even takes place will put you many steps ahead throughout your concrete’s life.
By addressing factors like drainage, grading, soil compaction, and using the proper base material, during the installation, you can help ensure your concrete stays in good shape and doesn’t settle.
Continuous maintenance and adjustments are also key to preserving the integrity of your concrete over time. For a comprehensive maintenance guide, check out this resource: How To Maintain Your Concrete
If you’re already struggling with settled concrete, you have options to fix it. Check out this guide to learn more: How To Fix Settling Concrete Slabs
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