Why Thermally Modified Wood for Covered Patio Walls?
Covered patio walls, while protected from direct rain and harsh sunlight, still experience fluctuations in temperature and humidity. These conditions can challenge untreated wood, leading to warping or checking over time. Thermally modified wood undergoes a high-temperature treatment process that alters its cellular structure, reducing its ability to absorb moisture. This process enhances the wood's dimensional stability, making it less prone to expansion and contraction with changes in ambient conditions.
The thermal modification process also imparts a consistent, rich brown tone throughout the wood, which can deepen or lighten over time depending on exposure and finishing choices. This material offers a natural aesthetic that can complement various architectural styles, from rustic to contemporary. Its improved stability means it can maintain its appearance more consistently in a covered outdoor setting.
Selecting the Right Thermally Modified Wood Profile
Thermally modified wood is available in various profiles, each offering a different visual effect and installation method. For covered patio walls, common choices include tongue-and-groove, shiplap, and square-edge profiles. The choice of profile influences the shadow lines, overall texture, and how water might shed, even in a covered area.
Tongue-and-groove profiles create a tight, interlocking fit, offering a smooth, continuous appearance. Shiplap provides a distinct overlap, creating a visible shadow line that can add depth and character. Square-edge profiles are often used for a more minimalist or open-joint look, which may require a backing material for a finished appearance. Consider the desired aesthetic and the level of protection needed when making your selection. For example, a shiplap profile can offer slightly better protection against wind-driven moisture than an open-joint square-edge profile, even under a cover.
Design Considerations for Covered Patio Walls
When designing with thermally modified wood for covered patio walls, consider the orientation of the boards (horizontal or vertical), the overall scale of the patio, and how the wood will interact with other materials. Horizontal installation can make a space feel wider, while vertical installation can create a sense of height. For a cohesive look, plan how the wood will meet corners, doors, and any windows.
Since these walls are part of an outdoor living space, think about how light will play across the surface at different times of day. The natural variations in thermally modified wood can be highlighted by strategic lighting. Also, consider the finish: while thermally modified wood can be left unfinished to weather to a silver-gray patina, applying an exterior-grade oil or stain can help maintain its original color and provide additional UV protection, even in a covered setting. Regular maintenance will be necessary to preserve the chosen finish.
Installation Best Practices for Covered Patio Walls
Proper installation is key to the longevity and appearance of thermally modified wood on covered patio walls. Although protected, these applications still benefit from good ventilation behind the cladding. A rainscreen system, even a simplified one, can help ensure air circulation and manage any incidental moisture. This typically involves furring strips installed vertically or horizontally, depending on the cladding orientation, to create an air gap between the wood and the wall substrate.
Fastening should be appropriate for outdoor use. Stainless steel fasteners are recommended to prevent staining the wood and ensure long-term holding power. For blind fastening, consider specialized clips or tongue-and-groove profiles designed for hidden fasteners. If face fastening, pre-drilling can help prevent splitting, especially with denser wood species. Always follow the manufacturer's specific installation guidelines for the chosen profile and species.
Ensure adequate clearance from the ground or patio surface to prevent moisture wicking into the bottom boards.
Worked Example: Patio Wall Cladding for a 10-foot by 8-foot Section
Let's consider a hypothetical covered patio wall section measuring 10 feet wide by 8 feet high. We'll use NORX thermally modified spruce, an 8-foot long tongue-and-groove profile with a 5-inch (nominal) face width. The actual coverage width per board is typically slightly less due to the tongue, let's assume 4.5 inches (0.375 feet) for calculation purposes.
First, calculate the total area: 10 feet (width) x 8 feet (height) = 80 square feet. Next, determine how many boards are needed for the width. 10 feet / 0.375 feet per board = 26.67 boards. Since you cannot purchase a fraction of a board, you will need 27 boards to cover the width. Each board is 8 feet long, so the total linear footage required is 27 boards * 8 feet/board = 216 linear feet.
This calculation assumes no waste for cuts or imperfections. It is generally recommended to add 10-15% for waste, especially if there are windows, doors, or complex cuts. For this example, adding 10% waste: 216 linear feet * 1.10 = 237.6 linear feet. Since boards are sold in full lengths, you would round up to the nearest full board, which would mean purchasing approximately 30 boards (237.6 linear feet / 8 feet per board = 29.7, rounded up to 30 boards). This ensures enough material for cuts, potential mistakes, and future repairs.
When planning, also consider the substructure. For this 10x8 foot wall, if cladding vertically, you would need horizontal furring strips every 16 or 24 inches on center. For horizontal cladding, vertical furring strips would be needed at similar spacing. Always verify the specific span ratings and fastener requirements for your chosen profile and local building practices.
Before you order
- Confirm the specific thermally modified wood species and profile are suitable for wall applications.
- Evaluate the level of exposure (wind, splash-back) even under cover, and plan for appropriate finishes/ventilation.
- Determine desired aesthetic: horizontal vs. vertical orientation, shadow lines, and natural weathering vs. maintained color.
- Plan for a ventilation gap (rainscreen) behind the cladding for optimal performance.
- Select appropriate fasteners (e.g., stainless steel) for outdoor durability and to prevent staining.
- Calculate material quantities, including a waste factor for cuts and unforeseen needs.
- Consider how the wood will interact with adjacent materials, corners, and openings.
- Establish adequate clearance from the ground or patio surface.
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 Dover, DE. 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, similar to other wood species. Even in a covered patio setting, UV exposure and ambient moisture can cause this color change. If you prefer to maintain the original brown tone, an exterior-grade oil or stain should be applied and regularly reapplied according to the manufacturer's recommendations.
Does thermally modified wood require a rainscreen system for covered patio walls?
While covered patio walls offer significant protection, incorporating a rainscreen system or at least a ventilation gap behind the thermally modified wood cladding is highly recommended. This air space promotes drying, helps manage any incidental moisture, and contributes to the long-term stability and performance of the wood, even in a semi-sheltered environment.
What kind of fasteners should I use for thermally modified wood on covered patio walls?
For any outdoor application, including covered patio walls, stainless steel fasteners are recommended. They resist corrosion, which prevents unsightly staining on the wood over time. The specific type (e.g., screws, nails) and length will depend on the wood profile, the thickness of the material, and the substructure. Always refer to the manufacturer's fastening guidelines for the chosen product.
Ready to Transform Your Covered Patio Walls?
Request a material quote with your project dimensions, desired profile, and ZIP code to confirm current availability and service options for thermally modified wood. Explore our selection of siding and cladding, including NORX and Maximo Accoya, to find the perfect fit for your project.
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