Frequently Asked Questions

Traditional timber and bolted access mats are made from a mix of hardwoods and softwoods without strict control over lumber grade, which can lead to variability in strength, durability, and performance. TerraLam, as an engineered cross-laminated timber (CLT) product, is designed for greater predictability—each mat is manufactured with careful material selection and quality control to provide more consistent load-bearing capacity, durability, and performance. This approach helps ensure mats are more likely to meet specifications, reducing variability and supporting efficiency on the job site.

TerraLam CLT mats are designed to offer enhanced strength and longevity. Unlike bolted mats, which transfer weight at mechanical fastener points, adhered CLT mats distribute more evenly across the entire surface, which can enhance stability and minimize stress points. The industrial adhesive used in their construction also serves as a moisture barrier, helping to protect layers from water intrusion and slow the effects of rot and decay. This design contributes to a stronger, more resilient mat that is built to perform consistently in demanding job site conditions.

The industrial moisture-activated polyurethane adhesive used in TerraLam mats plays a key role in their strength, durability, and longevity. Unlike bolted mats, where load transfer is limited to mechanical fasteners, TerraLam’s adhesive bonds every layer across the full surface, helping to distribute weight more evenly and reduce stress points.

Additionally, the adhesive serves as a moisture barrier, limiting water intrusion between layers and helping to slow rot, decay, and warping—especially in wet, humid, or extreme weather conditions. The adhesive is also chemically inactive before leaving the factory, ensuring minimal environmental impact when used on-site.

TerraLam CLT mats can be customized with reinforcements and specialized treatments to enhance their durability and performance in demanding conditions.

• Dowel Reinforcement – Red oak dowels are strategically placed to provide additional mechanical reinforcement, helping the mat withstand extreme stress and high shear forces without compromising usability. This reinforcement adds structural integrity, supporting long-term durability.
• Specialized Treatment – Mats can be immersed in a borate solution that penetrates deep into the wood fibers, creating an internal barrier against fungal growth, moisture, and environmental wear. This treatment can be beneficial for high-humidity, wet, or extreme temperature conditions, supporting long-term mat performance.

These enhancements allow TerraLam mats to provide added resilience and protection, making them a strong site access solution for projects that require additional durability.

TerraLam mats are available in 3-ply, 5-ply, and 7-ply construction to meet different project needs.

• TerraLam® 308 CLT – 8′ wide x 14′ or 16′ long (ideal for light-duty access roads and general ground protection)
• TerraLam® 504 CLT – 4′ wide x 16′ or 18′ long (designed for high-traffic areas and heavy equipment support)
• TerraLam® 508 CLT – 8′ wide x 16′ or 18′ long (provides a wider platform for stability and efficiency)
• TerraLam® 708 CLT – 8′ wide x 16′ or 18′ long (built for crane support and extreme load-bearing applications)

Each mat is engineered for optimal strength, durability, and efficiency, offering a reliable solution for temporary access roads, work platforms, and ground protection.

The TerraLam Connect System is a tethering solution designed to link adjacent mats, helping to reduce shifting and maintain stability on access roads and work platforms. This system can be especially beneficial in wetlands, flood-prone areas, and soft ground conditions, where mats may be more prone to separation.

By keeping mats more securely in place, the Connect System can enhance safety, improve load distribution, and support a stable surface for heavy equipment and crews, even in challenging environments.

The TerraLam Connect System is designed for simple installation and can typically be completed by one person using an impact driver. No pre-drilling is required. To install, position the TerraLam Connect strap so that each end rests on adjacent mats. Then, use an impact driver to install the screw through the bolt plate hole until it is firmly secured against the mat.

Before moving mats, the TerraLam Connect strap and lag screws must be removed. At the end of a project, straps and screws should be collected and returned to Sterling along with the TerraLam mats. Returned materials will be inspected and either re-used or responsibly recycled.

TerraLam CLT mats are designed for a variety of industries and job sites, providing stability, durability, and efficiency in challenging environments. They are commonly used in:

• General Construction – Helps protect ground surfaces and support heavy equipment.
• Electrical Utility Work – Provides a stable surface for bucket trucks, cranes, and digger derricks.
• Pipeline Construction – Creates a level foundation for pipe cradles, skids, and welding operations.
• Renewables (Wind & Solar Projects) – Supports transport and crane operations while helping protect sensitive environments.
• Civil Engineering & Infrastructure – Used for temporary access in bridge construction, road expansions, and similar projects.
• Disaster Recovery & Emergency Response – Establishes temporary access roads and staging areas for relief efforts in affected areas.

TerraLam CLT mats may be used for temporary bridges and outrigger support, but engineering approval is recommended for critical applications.

• Temporary Bridges – TerraLam mats can serve as a load-bearing surface for crossing trenches, ditches, or sensitive terrain. Their cross-laminated design enhances strength and weight distribution, offering a lightweight alternative to traditional timber mats.
• Outrigger Support – TerraLam helps distribute weight evenly, making it suitable for stabilizing cranes, aerial lifts, and heavy equipment. For high-load scenarios, dowel reinforcement or thicker ply options (such as the TerraLam 708 series) may be advisable.

For bridge decking, extreme loads, or specialized uses, consulting with a qualified engineer ensures the mats meet necessary structural requirements.

TerraLam mats have been tested in temperatures ranging from approximately -70°F to 150°F. While all wooden mats can become slippery in wet, muddy, or icy conditions, the solid top of TerraLam mats makes it easier to remove mud, snow, or ice. As they are used on-site, they naturally wear in, helping to improve traction over time.

TerraLam mats can often be repaired at a lower cost than bolted access mats. Repairs to bolted mats may require removing rusted or bent bolts and fragmented boards, while a damaged CLT mat remains a solid block of wood. Additionally, a damaged TerraLam mat does not expose crews to puncture hazards or equipment damage in the same way that a broken bolted mat might.

TerraLam CLT mats are constructed with kiln-dried southern yellow pine and bonded using a moisture-activated polyurethane adhesive. The wood’s natural moisture assists in curing the adhesive, creating a strong bond. Independent testing by organizations such as the USDA Forest Products Laboratory, San Diego State University, and Henkel Adhesives has supported the strength and durability of TerraLam products.

TerraLam CLT mats are designed with environmental considerations in mind, making them a strong option for sensitive areas like wetlands.

• Eco-Friendly Adhesive – The adhesive used in TerraLam mats becomes chemically inactive before leaving the factory, helping to minimize environmental impact. Unlike other mats, which contain metal fasteners that may oxidize and introduce contaminants, TerraLam mats are metal-free, simplifying disposal.
• Sustainable Sourcing – TerraLam mats are made from Southern Yellow Pine, which matures in approximately 20 years—much faster than the 80-100 years required for the hardwood species used in bolted mats. This supports responsible forestry practices.
• Prevention of Invasive Species – The solid top surface and adhesive-sealed layers help prevent dirt, debris, and invasive species from becoming embedded in the mat, reducing the risk of cross-contamination between job sites.

TerraLam mats are designed for efficiency, potentially reducing carbon emissions throughout their lifecycle. Their lightweight construction allows for 30% to 50% fewer truckloads compared to timber mats when transporting the same square footage, which can help lower fuel consumption and CO₂ emissions. Additionally, TerraLam mats provide greater coverage per mat, reducing the total number needed on-site and minimizing transportation and handling impacts.

Sterling actively tracks and measures Scope 1 & 2 emissions to improve sustainability and provides data-driven reporting to help partners estimate their Scope 3 emissions, supporting their environmental goals with measurable insights.

TerraLam mats help lower overall project costs through reduced transportation, faster installation, and long-term durability:

• Fewer Truckloads – Being 30-50% lighter than traditional timber mats, TerraLam mats allow more units per truckload. Fewer deliveries mean potential savings on fuel, transportation time, and emissions.
• Faster Installation & Removal – The lightweight design and uniform sizing enable quicker placement and removal, helping reduce labor and equipment time.
• Lower Maintenance Costs – The adhesive-sealed edges and moisture-resistant construction help slow rot, decay, and warping, reducing the frequency of replacements.
• Reusable & Resellable – With a longer lifespan than traditional mats, TerraLam can be used for multiple projects and may retain resale value, offering additional cost savings.

TerraLam mats are designed for easier handling, requiring common job site equipment for installation and relocation. Commonly used equipment includes:

• Excavator with a mat grapple – The preferred method for precise placement and efficient handling.
• Forklift or loader – A minimum 6-foot fork is recommended to securely lift and transport mats without risk of damage.
• Telehandler – Provides extended reach and flexibility, especially useful in confined job site conditions.

Because TerraLam mats are lighter than traditional mats, they can typically be handled with fewer crew members and reduced equipment time, supporting cost-effective and efficient site access.

The best option depends on your project needs, budget, and long-term plans. A Sterling expert can help assess your specific situation to determine whether renting, leasing, or purchasing TerraLam mats is the most cost-effective solution for your business.