Foundations are a critical part of all MT Solar mounts. They’re vital to structural integrity and the high endurance our solar mounts provide in all types of terrain and against tough environmental conditions. Foundations are also part of what enables our mounts to support extensive solar arrays for optimal energy output.

Because they’re so essential to a successful installation, mount foundations merit a closer look. In this article, we’ll cover their basics and benefits, as well as how some project-specific details can impact their design and the planning and preparation of solar mount installation.

Standard foundations for MT Solar mounts are made from poured cement and are used to stabilize a steel pole, which then supports the mount. A single-pole mount will require only one foundation, while a multi-pole mount will need one foundation for every pole.

Although they do a big job, MT Solar mount foundations are not especially complex. In terms of structure and purpose, they have a lot in common with concrete-embedded fence posts. Installation starts by digging a hole to a specified depth and shape, bracing a steel pole in the center, and pouring cement to ground level. The result is a low-profile, highly durable, and supportive mount base.

Once the foundation and pole are set, the mount’s frame can be assembled around it and hoisted for the rail and array assembly, wiring and bonding, and then to the top of the pole to complete the solar mount.

Direct benefits for installers and end-users are always a priority for MT Solar. Before even assembling the mount, and as early as the planning stages, the standard mount foundation contributes to a simpler process for installers and high-performance reliability for end-users.

Fewer Posts, Fewer Penetration Points, Less Excavation

Top-of-pole mounts minimized the number of ground penetration and contact points needed to support robust solar arrays. The ground does not need to be leveled to dig foundation holes. Fewer excavation and groundwork requirements amount to lower costs for materials, labor, resources, and time.

Economical, Easy to Source and Install Material

Raw steel poles, cement mixing and excavation services, a few tools, and some thoughtful planning and measuring are all it takes to realize a foundation that’s ready for solar mount assembly. These materials and services are easy and economical to source for the vast majority of projects.

Sustainable Land Use and Maintenance

Limited penetration points and a simple concrete embedment make it easy to use and maintain the ground directly below the mount. There’s no need to introduce harsh or permanent weed control methods. Landscaping equipment can be safely operated around each pole and foundation surface. Even on multi-pole mounts, it’s easy to access the surface and underside of the array for cleaning, maintenance, and changes in the tilt angle.

As a standard, MT Solar mounts are built on one of two foundation types: square or round. When you design a mount in the Solar Mount AutoDesigner, you’ll see these options within the Foundation Size field.

Although round and square foundations serve the same function and either type can be used in many settings, there are a few differences between them, which will affect where they are best utilized.

Square Foundations

Square foundations are always 48 inches in length and width. They can be considered the default foundation for MT Solar mounts. They require less cement, but they will require more of the ground to be disturbed during the excavation and will reduce the amount of soil or material below the mount. They work in soil classes 1 through 4 per U.S. Land Use and Soil Classification standards.

Round Foundations

Round foundations are always 36 inches in diameter. Although smaller than the square option, they require a greater depth and therefore more cement. If minimal ground disruption is a priority, such as for agrivoltaics and solar mounts installed on existing asphalt or pavement, round foundations can be a better option. They also work in soil classes 1 through 4.

Foundation Depth

Foundation depths vary based on project specifics. The shape impacts foundation depth, along with other structural and site factors. Greater snow loads and wind exposure, the higher the mount’s ground clearance, and the steeper its tilt will typically require a deeper foundation and more concrete.

Don’t Fill the Pole With Cement

When setting the pole and pouring the foundation, make sure to leave the pole empty. Filling the pole can create structural vulnerabilities as the concrete within will be subject to temperature fluctuations that can cause cracking. When wiring the mount, the pole can be used to hide the conduit, but this is not a requirement.

Make the Most of the Excavator

By attaching the pole to the bucket, the excavator can assist with lifting and setting poles in place. It’s also a timesaver for digging and filling trenches for the conduit and foundation grading once the concrete has set.

Uncrate and Assemble With Speed and Ease

After the foundation and pole are set, place the mount pallet within 10 to 15 feet. This will make the assembly more efficient by keeping all of the components within reach without anything getting in the way before it’s needed.

The end-use goals for the solar mount, the overall project budget, and access to equipment are a few factors that affect foundation options. Depending on your needs, sometimes non-standard solutions and workarounds are required.

Although MT Solar does not provide design and engineering services to develop foundation alternatives, the construction drawings and calculation packet output from the AutoDesigner provide all of the specifics an engineer would need to create an adequately supportive mount anchoring solution.

Anchoring a Solar Mount on Existing Structures

MT Solar mounts can be mounted to flat roofs, storage containers, and other structures using various attachment methods. In these projects, the concrete foundation is bypassed in favor of components like base plates.

Embedding in Sites With Bedrock, Tough Terrain, and Shallow Soil

At sites where the ground is difficult or impossible to excavate to the depth specified in the mount’s construction drawings, concrete foundations can be modified to shallower depths and wider widths. This will provide structural support that’s comparable to foundations output by the AutoDesigner and bypass the need to cut into bedrock or other tough terrain.

Keeping Soil Undisturbed

If soil must be kept undisturbed, which is sometimes a requirement for agrivoltaics installations, pile-driven solar mount foundations are a reliable option that bypasses ground excavation and cement pouring.

Whether you plan to install a mount with a standard concrete embedded foundation or you’ll need a custom or alternative anchoring system, the process starts in the Solar Mount AutoDesigner, which will give you the engineering specs needed to move forward with your project. You can also reach out to us for expert guidance through the Design and Estimate Assistance request form.