Concrete Foundations Contractor In Houston TX
Commercial Concrete Foundations Engineered and Built to Last
Texas and Louisiana are challenging states for foundation construction. Large swaths of land in both states are underlain with black clays, which is not ideal for construction. While they’re excellent for farmers, black clays have a tendency to shift, swell, and contract as the weather changes. This cycle produces differential pressures along the foundation’s face, increasing the chances of failure.
In fact, Texas leads the nation in foundation failures, so if you’re planning out a commercial construction project, you’ll need to pay extra attention to your foundation’s quality.
What Types of Foundations are Built Along the Gulf Coast?
As you go north, the nature of foundation construction changes. In northern climates, where the frost line extends deep into the soil, crawlspaces and basements are the norm. Down here along the Gulf Coast, though, the ground rarely freezes more than an inch or two deep. Deeper concrete foundations aren’t required to compensate for this “deep freeze.”
Instead, residential and commercial buildings in Texas and Louisiana are usually supported by a slab-on-grade foundation. Also called a “pad,” slab-on-grade foundations are exactly what they sound like – an even slab of concrete installed on top of graded soils.
There are several varieties of slab-on-grade foundations, including floating or monolithic foundations. Floating foundations raise the slab off the soil, while monolithic foundations are poured as a single piece, footings and all.
An alternative to slab-on-grade foundations is a mat foundation. Mat foundations provide additional load bearing support for the building and are designed to accommodate concrete columns for even more support. Mat foundations are recommended when the soil’s load bearing capabilities are poor.
Slab-on-grade Foundations Can Also be Reinforced Through Post-tensioning
Slab-on-grade foundations can either be reinforced using steel rebar or by using post-tensioning cables. When installing a post-tensioned foundation, the tendons are laid out in a grid-like pattern, much like a grid of rebar. Concrete is poured over these tendons, and the tendons are then pulled using a post-tensioning jack and pump system. This applies high amounts of tension to the cables, compressing the concrete and keeping it in a pre-stressed state. In theory, this helps the slab hold together even if it is subjected to intense lateral movement.
There is significant debate over which approach – rebar or post-tensioning – is better. Among engineers, the choice often comes down to familiarity.
A Few Advantages of Slab-on-grade Foundations
For the vast majority of commercial projects, though, a slab-on-grade foundation does the job well. Better than well, in fact, because slab-on-grade foundations have been the standard for decades in warmer climates. There are a few reasons for this, including:
- Economy – Slab-on-grade foundations are much less expensive than other types of foundations, as less labor and equipment is required to install one.
- Speed of installation – Because there’s less work to do during slab-on-grade installation, the process is typically much faster than digging out a basement or developing a crawlspace.
- Reliability – When properly installed and reinforced, a slab-on-grade foundation will provide 20 to 30 years of reliable support before significant wear is likely to emerge.
What Does the Slab-on-grade Construction Process Entail?
While slab-on-grade foundations are easier to install than other types of foundations, the process is still extensive and requires care. For most projects, this is what it generally looks like:
- Soil and site inspection – Before a foundation contractor can start construction, they need to know what kind of soil they’re working with. That’s why the first step is to take a boring of the development site and analyze the soils inside. This will help the project engineer ascertain load bearing capabilities and likelihood of shifting.
- Grading and compaction – Once the soil’s composition is understood, it’s shaped, graded and compacted. Grading and compacting ensures the soils are stable and ready to take the foundation.
- Extraction for footings – Most slab-on-grade foundations are built with footings that provide additional foundation stability. These footings are installed deeper in the ground, compared to the rest of the slab. To accommodate this added depth, an extractor is used to dig out the dirt.
- Placing the base – To promote better drainage and stability, a base material is installed on the build pad first. Gravel is the base material of choice in most cases.
- Placing a vapor barrier – In areas where excessive moisture is a concern, a vapor barrier is installed over the base like a sheet. Vapor barriers are made from impermeable polymers and can be cut to custom sizes and shapes. Once placed, the vapor barrier will protect the concrete from any moisture rising up within the soils.
- Installing reinforcement – The steel rebar or post-tensioning cables are arranged next, and it’s common for a commercial foundation project to include hundreds of them. They’re aligned in grid-like formation and mounted on top of rebar chairs to properly align them within the slab. The reinforcement is anchored at the edge of the slab to ensure it remains in place during pouring.
- Concrete pumping and pouring – With everything formed out and placed, it’s time to pour the concrete. For large commercial foundations, it’s common for the concrete team to use a boom pump. With its extended reach, a boom pump can access every square foot of the foundation without any workers setting foot on it.Concrete is poured from a low height and vibrated to minimize any trapped air.
- Curing and finishing – Now, all that’s left to do is to level out the concrete and give it time to cure. The foundation team may use chemical curing agents to facilitate this step, as chemical curing agents help maintain optimal water content levels for curing.
Need a Foundation? Work With an Experienced Houston Concrete Contractor
Although concrete foundations are expert-level jobs, there are no licensing requirements for concrete foundation contractors in Texas. All that’s required is an approved construction plan, which must be developed, in part, with an engineer’s assistance.
If your organization is considering a commercial build, it’s highly recommended that you work with an experienced foundation team to execute the project. Reputable foundation installers have one or more engineers on staff, so they can develop structurally-sound, compliant plans that meet local building codes.
That’s important because your building’s foundation will be expected to provide decades of support for your new construction. To create a foundation that’s reliable, there can be no shortcuts or guesswork during the process. Precision is key, and that’s what a reputable team like American Paving offers to its clients.