Understanding Thermally Modified Wood for Exterior Walls
Thermally modified wood undergoes a high-heat treatment process that alters its cellular structure. This modification enhances the wood's dimensional stability, making it less prone to shrinking, swelling, and warping when exposed to fluctuations in temperature and humidity. For covered patio walls, which experience indirect weather exposure, this stability is a key advantage.
The thermal modification process also reduces the wood's ability to absorb moisture, which contributes to its resistance against decay and insect infestation. While covered walls are protected from direct rain, they still experience ambient humidity and temperature changes, making these properties beneficial. The natural appearance of thermally modified wood also offers an aesthetic that can complement various architectural styles.
Profile Selection for Covered Patio Walls
The choice of profile significantly impacts the visual texture and installation method of your covered patio walls. Common profiles for exterior wall applications include tongue-and-groove, shiplap, and square-edge boards. Each offers a different aesthetic and functional characteristic.
Tongue-and-groove profiles create a tight, interlocking fit, offering a smooth, continuous surface that can help protect the substructure. Shiplap profiles provide a distinctive overlap, creating shadow lines that add depth and character to the wall. Square-edge boards, when installed with a consistent gap, can create a more open, modern look, often used in rainscreen-style assemblies.
When selecting a profile, consider the desired visual effect and how it integrates with the overall design of your patio and home. For a seamless look, narrower boards might be preferred, while wider boards can make a statement. The specific dimensions of NORX thermally modified wood include various thicknesses and widths, allowing for design flexibility. For example, the NORX Cedar or NORX Spruce options often come in profiles suitable for cladding, which can be adapted for covered patio walls.
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Finishing and Appearance Options
Thermally modified wood can be left unfinished to gradually weather to a silver-gray patina, or it can be finished with stains or oils to maintain or alter its original color. For covered patio walls, the decision to finish depends on the desired aesthetic and the level of maintenance you are prepared for.
If left unfinished, the wood will develop a natural weathered look over time. This can be a desirable aesthetic, but the rate and uniformity of weathering can vary depending on exposure to UV light and moisture. For a more consistent appearance, or to achieve a specific color, applying a high-quality exterior finish is recommended. Finishes can help protect the wood from UV degradation and moisture absorption, although the thermal modification process already provides a good base level of resistance.
When choosing a finish, consider products designed for exterior wood, such as penetrating oils or semi-transparent stains. These finishes allow the natural grain of the wood to show through while providing protection. Always follow the manufacturer's recommendations for application and reapplication to ensure optimal performance and longevity of the finish.
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Installation Considerations for Covered Patio Walls
Proper installation is crucial for the performance and appearance of thermally modified wood on covered patio walls. Even in a covered application, it is important to ensure adequate ventilation behind the cladding to prevent moisture buildup. This can often be achieved through a rainscreen-style assembly, where a small air gap is maintained between the wood and the wall's substructure.
Fasteners should be corrosion-resistant, such as stainless steel screws, to prevent staining and ensure long-term holding power. Hidden fastener systems are often preferred for a clean, uninterrupted surface aesthetic, but face fastening can also be used, provided the fasteners are countersunk and appropriate for the wood species and profile.
When planning your layout, consider the length of the boards and how they will meet at corners or around openings. Mitered corners can create a clean, seamless look, while butt joints with trim can offer a more traditional finish. Always allow for a small expansion gap at ends and edges, as wood, even thermally modified, will still exhibit some movement.
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Hypothetical Project Example: Covered Patio Wall in Albany
Consider a homeowner in Albany, NY, planning to clad a new covered patio wall measuring 10 feet wide by 8 feet high. They choose NORX Thermally Modified Spruce in a 5.5-inch face-width shiplap profile for its durability and clean lines. Each board is 12 feet long.
The wall area is 10 ft * 8 ft = 80 square feet. With a 5.5-inch (0.458 ft) face-width board, the number of courses needed vertically is 8 ft / 0.458 ft = 17.47. Rounding up, 18 courses are needed. Each course is 10 feet long. If using 12-foot boards, each 12-foot board can yield one 10-foot section with a 2-foot offcut. To minimize waste and simplify cuts, the homeowner might opt to purchase enough 12-foot boards to run horizontally.
For 18 courses of 10-foot length, and using 12-foot boards, 18 boards would cover the width. However, if the boards are installed vertically, 10 feet wide / 0.458 feet per board = 21.83 boards. Round up to 22 boards. Each board needs to be 8 feet long. If purchasing 12-foot boards, each board can yield one 8-foot section with a 4-foot offcut. For 22 boards at 8 feet each, this requires 22 individual 8-foot lengths. If purchasing 12-foot boards, 22 boards will be needed, resulting in 22 reusable 4-foot offcuts.
For a clean horizontal installation, the homeowner would purchase 18 boards, each 12 feet long. Each 12-foot board will be cut to 10 feet, leaving a 2-foot offcut. This results in 18 * 10 = 180 linear feet of material, or 18 boards. The total purchase would be 18 boards of 12-foot length.
This example assumes no significant waste from defects or complex cuts around windows/doors. The homeowner would also factor in a small overage, typically 5-10%, for cuts, potential mistakes, and future repairs. For this project, they might order 20 boards to account for this overage.
The installation would involve fastening the shiplap boards horizontally to vertical furring strips, creating a ventilation gap behind the cladding. A clear, penetrating oil would be applied to maintain the wood's warm tone and provide UV protection.
Before you order
- Determine the desired aesthetic: natural weathered look or finished color?
- Select the appropriate profile (tongue-and-groove, shiplap, square-edge) for the design and installation method.
- Verify the dimensions and availability of chosen thermally modified wood profiles.
- Plan for ventilation behind the cladding, considering a rainscreen assembly.
- Choose corrosion-resistant fasteners suitable for exterior use and the chosen profile.
- Calculate material quantities, including an overage for cuts and waste.
- Consider corner detailing (mitered vs. butt joint with trim).
- Select an appropriate exterior finish, if desired, and understand its maintenance requirements.
Confirm installation details, approved uses and warranty terms in the current instructions for the exact product and profile. Your installer should verify the substrate, structure and applicable project requirements.
This is a planning guide for projects in Albany, NY. Ask our team to confirm availability, delivery to your ZIP code and which branch can support your order.
Questions to help you decide
Can thermally modified wood be left unfinished on covered patio walls?
Yes, thermally modified wood can be left unfinished. It will naturally weather to a silver-gray patina over time. The rate and uniformity of this weathering will depend on the level of UV exposure and protection from direct rainfall on your covered patio. Applying a finish can help maintain the original color and provide additional UV protection, but it is not strictly required for the wood's performance.
What kind of fasteners should I use for thermally modified wood on covered patio walls?
For installing thermally modified wood on covered patio walls, it is recommended to use corrosion-resistant fasteners. Stainless steel screws are an excellent choice as they prevent staining of the wood and offer long-term holding power. Depending on the profile, you might use face fastening or a hidden fastener system for a cleaner look. Always ensure fasteners are appropriate for the wood species and the intended application.
Does thermally modified wood require a rainscreen system even for covered walls?
While covered walls offer protection from direct rain, they are still exposed to ambient humidity and temperature fluctuations. A rainscreen-style assembly, which creates a small air gap between the cladding and the wall's substructure, is generally recommended. This gap promotes ventilation, helping to prevent moisture buildup behind the wood and contributing to the longevity and stability of the entire wall system. Always refer to specific installation guidelines for your chosen product.
Ready to Plan Your Covered Patio Walls?
Request a material quote with your project dimensions, exact profile, and ZIP code to confirm current availability and service options for thermally modified wood. We can help you find the right materials for your Albany, NY, project.
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