BOARDS
S3S Lumber Boards
Surfaced on three sides for a smooth, finished appearance, S3S boards deliver clean lines and precise, consistent dimensions across every piece. The industry-standard board format, they are a versatile foundation for a wide range of applications, including molding, trim, decking, handrails, and shelving. Machined in stable, straight-grained substrates and available primed for paint or ready to finish, S3S boards install cleanly and hold their finish over time, making them a dependable choice for both interior and exterior projects. Standard and custom lengths are available through CTI's mill programs.
3 Substrate Options
1 Machining Option
10 Year Warranty
Sizes
Widths: 1.5 to 11.25"
Thicknesses: 7/16" to 1 1/4"
Colors
Substrate Options
Falcata
Our newly engineered Falcata substrate offers a clear profile for easy machining, and A-grade fibers at its base, making it a reliable, lightweight, and user-friendly option.
Pine
Pine is known for its versatility and workability. It offers excellent strength and stability, making it ideal for a wide range of construction and millwork applications.
LVL
LVL (Laminated Veneer Lumber) is an engineered wood product that offers superior strength and stability. It is composed of multiple layers of thin wood veneers, glued together to form a single, solid piece.
Machining and Customization
CTI components are machined in-house to precise, repeatable tolerances and arrive prepped and ready to install.
Available operations include:
Custom Length
Cut to your exact length, no field cutting.
Frequently Asked Questions
What does S3S mean?
S3S stands for surfaced three sides, meaning the board is milled smooth on three faces for a clean, finished appearance. It is the industry-standard board format for a wide range of trim and millwork applications.
What are S3S boards used for?
S3S boards are versatile enough for molding, trim, decking, handrails, and shelving, in both interior and exterior projects.
Are S3S boards available primed or finished?
Yes. S3S boards are available primed for paint or ready to finish, and they machine and accept paint or stain cleanly.
What lengths are S3S boards available in?
Standard lengths run up to 16 feet, with custom lengths available through CTI's mill programs.
Is this product covered by a warranty?
Yes. Every CTI product carries a 10-Year Manufactured Defect Warranty, ensuring it is free from material and workmanship defects under normal use.
What does S4S mean?
S4S stands for surfaced four sides, meaning the board is milled smooth on all four faces. This makes it ideal for exposed applications where every side may be visible.
Related Products
S4S Lumber Boards
S4S lumber boards surfaced smooth on all four sides, milled from stable Radiata Pine. Ideal for exposed trim, shelving, cabinetry, and general millwork applications.
S1S2E Exterior Cedar Trim Boards
Provides a beautiful, durable solution for exterior applications. This board is perfect for adding a touch of elegance and resilience to your projects while offering an easily-finished installation.
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Shiplap & Beadboard
Designed for both aesthetic appeal and practical functionality. They offer a modern, comfortable look that is ideal for interior walls and is engineered to be installed in either direction for added versatility.
Technical Details and Resources
Each CTI product comes with a 10 Year Manufactured Defect Warranty, ensuring they are free from material and workmanship defects under normal use for the product's lifetime. This commitment to quality offers you peace of mind and guarantees that you are investing in products built to last. You can view our product-specific warranties below.