High-Performance Solid Wood Installation Guidelines

Applications:
Interior Flooring • Exterior Decking • Architectural Wood Applications

Installation Methods Covered:
Full-Spread Direct Glue-Down Flooring Installation
CAMO Edge-Screw Exterior Decking Installation

Objective:
Maximum Stability • Quiet Performance • Long-Term Durability • Proper Installation Practices

About Thermawood-USA Solid Wood Products

Thermawood-USA products are genuine solid wood products that have undergone a thermal modification process designed to greatly improve dimensional stability, moisture resistance, and long-term performance.

The thermal modification process uses controlled heat and steam in an oxygen-controlled environment to change the internal structure of the wood. This reduces the wood's ability to absorb and release moisture, resulting in significantly reduced expansion, contraction, cupping, and warping compared to untreated wood.

However, Thermawood-USA remains real solid wood.

Like all natural wood products, it still responds to environmental conditions including humidity, temperature changes, and installation conditions. Proper installation practices are essential to achieving the maximum performance of the material.

Interior Flooring Installation Guide

Application: Full-Spread Direct Glue-Down Installation

The Foundation Comes First

Before opening a single bucket of adhesive, the foundation must be correct.

A successful flooring installation begins with a subfloor that is:

• Structurally sound
• Stable
• Flat
• Dry
• Free of defects and contaminants

Any movement, loose panels, high seams, uneven areas, moisture issues, or damaged sections of the subfloor must be corrected before installation begins.

The flooring system can only perform as well as the surface beneath it.

Why We Recommend Full-Spread Glue-Down Installation

Thermawood-USA flooring is thermally modified to greatly reduce the expansion, contraction, cupping, and warping normally associated with traditional wood flooring.

However, Thermawood-USA is still real wood. The natural grain structure of wood will always respond to changes in its environment.

The subfloor beneath the flooring is also still subject to seasonal movement as humidity levels change.

Traditional staples and cleats mechanically attach flooring at individual points. As the subfloor naturally moves, those fixed attachment points can transfer stress into the flooring system over time.

A premium full-spread adhesive installation creates a continuous bond between the flooring and subfloor.

This allows the entire floor system to work together by:

• Reducing stress points
• Providing continuous support
• Improving sound performance
• Creating a solid feel underfoot
• Helping maintain long-term stability

For these reasons, Thermawood-USA recommends a full-spread direct glue-down installation using only a high-quality 100% moisture-cure urethane wood flooring adhesive.

Interior Flooring Installation Procedure

Step 1 – Prepare the Subfloor

The subfloor must be:

• Structurally sound
• Properly secured
• Flat within accepted flooring tolerances
• Clean and free of dust, debris, paint, drywall residue, and contaminants
• Dry and suitable for hardwood flooring installation

Sand down high seams, correct uneven areas, repair damaged sections, and vacuum thoroughly before adhesive installation begins.

Step 2 – Establish a Perfect Starting Line

The first row of flooring sets the direction for the entire installation.

Instead of permanently fastening the starting row:

1. Snap a laser line or chalk line for the starting location.
2. Fasten a straight sacrificial board along this line.
3. Use this temporary board as a solid reference point while installing the first rows.
4. Remove the temporary board after adhesive has fully cured.

This method creates a perfectly straight starting point without leaving permanent fasteners in the finished floor.

Step 3 – Select the Proper Adhesive

Thermawood-USA requires the use of a high-quality, 100% moisture-cure urethane wood flooring adhesive.

The adhesive must be specifically designed for hardwood flooring applications and provide:

• Strong permanent bond
• Long-term durability
• Flexibility to accommodate normal wood movement
• Proper support across the entire floor surface

Thermawood-USA does not recommend lower-grade adhesives, general construction adhesives, or products not specifically engineered for hardwood flooring installations.

Always follow adhesive manufacturer requirements for:

• Approved subfloor conditions
• Trowel size
• Coverage rate
• Open time
• Cure time

Step 4 – Apply the Adhesive

Apply urethane flooring adhesive using the trowel size recommended by the adhesive manufacturer.

A true full-spread application is required.

The goal is complete and consistent support beneath the entire flooring system.

Do not substitute:

• Isolated adhesive beads
• Random glue lines
• Glue-assist methods intended for nail-down installations

Step 5 – Install the Flooring

Place each Thermawood-USA board directly into the wet adhesive bed while engaging the tongue-and-groove profile.

Maintain proper alignment during installation using professional flooring straps, clamps, or approved hardwood installation tools.

Keep flooring under proper tension until adhesive has cured according to the adhesive manufacturer's recommendations.

The finished installation should remain free of permanent mechanical fasteners throughout the flooring field.

Interior Flooring Long-Term Performance

When installed over a properly prepared subfloor using a high-quality urethane adhesive system, Thermawood-USA flooring provides:

• Exceptional dimensional stability
• A solid feel underfoot
• Reduced noise compared to mechanically fastened installations
• Long-term durability while maintaining the natural beauty of real hardwood

Maintaining proper indoor humidity levels will help ensure the best possible long-term performance.

Exterior Decking Installation Guidelines

Recommended Fastening System

Thermawood-USA recommends a dual-action installation system:

1. Polyurethane exterior adhesive applied to framing members
2. CAMO Edge-Screw fastening system using 316 stainless steel screws

This system provides:

• Improved board stability
• Reduced movement
• Cleaner hidden-fastening appearance
• Easier future board replacement

Required Installation Materials

• CAMO Marksman Pro Jig
• CAMO 316 stainless steel Edge Screws
• CAMO Pre-Drill Bit
• High-quality polyurethane exterior adhesive

Decking Installation Notes

Thermawood-USA decking is thermally modified for exceptional stability and durability. However, it remains a genuine solid wood product, and proper installation practices are still important.

Recommended installation practices include:

• Pre-drilling fastener locations
• Maintaining proper edge and end distances
• Using 316 stainless steel fasteners
• Avoiding overdriving screws
• Following CAMO installation recommendations

Pre-Installation Acclimation Recommendation

Although Thermawood-USA decking has been thermally modified for exceptional stability, it is still a genuine solid wood product.

Before installation, decking boards should be allowed to acclimate to jobsite conditions whenever practical.

Recommended practices:

• Store decking flat, elevated off the ground, and protected from direct weather exposure.
• Allow boards to adjust to local environmental conditions before installation.
• Avoid installing decking immediately after delivery if material has been stored in significantly different conditions.
• Keep boards clean, dry, and properly supported.

Thermal modification greatly reduces moisture-related movement compared to untreated wood. Allowing boards to acclimate before installation helps minimize adjustment after installation and contributes to a more consistent finished deck.

Pre-Installation Sealing Recommendation

Protecting decking before installation is an important step in achieving the best appearance and long-term performance.

Before installation:

• Lay boards out on a clean, protected surface.
• Apply sealer to all six sides of the board, including the face, back, edges, and ends.
• Seal any freshly cut ends immediately after cutting during installation.

The end grain is the most vulnerable area of any wood product because it can absorb moisture more readily than the face of the board.

Thermal modification greatly improves wood stability and durability, but protecting exposed end grain and surfaces remains a responsible installation practice.

Recommended Exterior Finishes and Natural Weathering

Thermawood-USA decking can be left to naturally weather over time, allowing the wood to develop a silver-gray patina commonly associated with coastal and Cape Cod-style architecture.

Many homeowners, designers, and architects appreciate this natural weathered appearance and choose to allow the decking to age naturally.

For those who prefer to maintain more of the original wood color, Thermawood-USA recommends using a premium exterior wood finish containing UV protection.

A quality UV-protective exterior finish helps:

• Reduce UV-related color change
• Maintain more of the wood's original appearance
• Provide a more consistent color over time
• Protect the surface from outdoor exposure

The choice between natural weathering and maintaining the original wood tone is primarily an aesthetic preference.

Products such as Cutek and other premium exterior hardwood finishes are commonly used with high-end decking applications.

Always follow the finish manufacturer's application and maintenance instructions.

Long-Term Deck Maintenance

Proper maintenance helps preserve the appearance and performance of Thermawood-USA decking.

Recommended maintenance:

• Clean the deck periodically as needed.
• Pressure wash carefully using appropriate settings for wood decking.
• Reapply a quality UV-protective exterior finish as desired.

Maintenance frequency depends on:

• Amount of direct sunlight
• Local climate
• Weather exposure
• Deck orientation
• Desired appearance

A properly installed and maintained Thermawood-USA deck will continue to provide the natural beauty and performance expected from premium thermally modified solid wood.

Technical Summary

Thermawood-USA combines the natural beauty of real solid wood with advanced thermal modification technology.

Proper installation practices including:

• Correct subfloor preparation
• Full-spread adhesive installation
• Proper decking fastening
• Acclimation
• End-grain protection
• Quality finishing systems

allow Thermawood-USA products to deliver exceptional stability, durability, and long-term performance.