Refreshing a Facade with Thermally Modified Wood

Assess Your Existing Facade: Beyond Aesthetics

Before any new material is chosen, a thorough assessment of your existing facade is crucial. This goes beyond just disliking the current color or texture. Look for signs of structural issues, water intrusion, or deteriorated components. Are there areas of rot, cracked stucco, loose siding panels, or peeling paint? These issues must be addressed and repaired before new cladding is installed.

Consider the existing wall assembly. Is it a rainscreen, direct-to-sheathing, or another system? Understanding the current construction helps in planning how thermally modified wood will integrate. Document any existing flashing details around windows, doors, and corners, as these will need to be replicated or improved upon with the new installation. A professional inspection can help identify hidden problems that might impact the longevity of your refreshed facade.

Choosing Thermally Modified Wood Profiles and Species

Thermally modified wood is available in various profiles, each offering a different aesthetic and installation method. Common profiles include tongue-and-groove, shiplap, and square-edge boards. The choice of profile influences the shadow lines, overall visual texture, and how water sheds from the facade.

For example, a shiplap profile creates distinct horizontal or vertical lines with overlapping edges, while tongue-and-groove offers a tighter, more seamless appearance. Square-edge boards can be installed with intentional gaps for a modern, open-joint look, often requiring a rainscreen assembly behind them. NORX offers thermally modified spruce, which is known for its consistent grain and a warm, inviting tone that can be enhanced with various finishes or allowed to weather naturally. Another option is Maximo thermally modified ash, which provides a darker, richer color and distinct grain patterns. Consider how the chosen profile and species will complement the architectural style of your home and the surrounding landscape.

You can explore available options at our product pages: Thermally Modified Wood and NORX Thermally Modified Wood.

Planning Layout and Orientation: Horizontal vs. Vertical

The orientation of your thermally modified wood cladding significantly impacts the facade's perception. Horizontal installation can make a building appear wider and more grounded, often evoking a traditional or rustic feel. Vertical installation, conversely, can emphasize height and create a more contemporary or formal aesthetic.

When planning the layout, consider how the chosen orientation interacts with architectural features like windows, doors, and rooflines. Vertical cladding can draw the eye upwards, while horizontal lines can provide a sense of expansive continuity. It's also important to plan for transitions at corners and around openings to ensure a clean, professional finish. For complex facades, sketching out different layout options can help visualize the final outcome.

Worked Example: Refreshing a Gable End with Thermally Modified Wood

Let's consider a hypothetical gable end wall measuring 20 feet wide at the base and 12 feet high at its peak, forming a triangle. The existing siding is deteriorated, and the homeowner wants to replace it with thermally modified wood, installed horizontally, using a shiplap profile with 5.5-inch (nominal 1x6) exposed face width.

First, calculate the area of the gable end: (Base x Height) / 2 = (20 ft x 12 ft) / 2 = 120 square feet. For horizontal installation, boards will be cut to fit the diminishing width of the gable. Assuming minimal waste from cuts, we can use the total area for an initial material estimate. Each board has an exposed face width of 5.5 inches (or 0.458 feet).

Linear feet needed: 120 sq ft / 0.458 ft = approximately 262 linear feet. If boards are typically sold in 8-foot lengths, you would need 262 / 8 = 32.75 boards. Rounding up, you would purchase 33 boards. However, this calculation does not account for cutting waste, especially for horizontal installation on a gable where many short pieces will be generated towards the peak.

A more practical approach for a gable would be to estimate by course. The height of the gable is 12 feet, which is 144 inches. With a 5.5-inch exposed face, you would need 144 / 5.5 = approximately 26 courses of boards. The longest course is 20 feet. The shortest course will be near the peak. You would need to purchase enough boards to cover the cumulative length of these courses, plus a waste factor. For a gable, a waste factor of 15-20% is often prudent due to angled cuts and short pieces. So, 262 linear feet * 1.20 (20% waste) = 314.4 linear feet. If 8-foot boards are used, 314.4 / 8 = 39.3, so 40 boards would be a safer purchase.

It's critical to review the manufacturer's specific installation guidelines for any recommended spacing or overlap, as this can affect the actual coverage per board and thus the total quantity needed. Always round up when purchasing materials to account for cuts, potential errors, and future repairs.

Considering Fasteners, Flashing, and Substructure

A facade refresh isn't just about the visible cladding; the underlying components are equally vital. Appropriate fasteners are essential for securing the thermally modified wood. Stainless steel fasteners are often recommended to prevent staining and ensure long-term holding power, especially in exterior applications. The type and length of fasteners will depend on the thickness of the cladding and the substructure.

Flashing around windows, doors, and at transitions is critical for diverting water away from the wall assembly. New or updated flashing might be required to ensure proper water management with the new cladding. The substructure, typically furring strips or a rainscreen system, provides a level surface for installation and allows for airflow behind the cladding, which is beneficial for moisture management. Ensure the existing substructure is sound, or plan to install a new one that meets current building practices for rainscreen assemblies.

Finishing and Maintenance Considerations

Thermally modified wood can be left unfinished to weather to a natural silver-gray patina, or it can be finished with stains or oils to maintain or enhance its color. The decision to finish the wood should be made before installation, as it impacts the long-term appearance and maintenance schedule.

If left unfinished, the wood will gradually change color when exposed to UV light and moisture. If a consistent color is desired, periodic reapplication of a suitable exterior finish will be necessary. This maintenance should be factored into the long-term plan for your facade. Always follow the finish manufacturer's instructions for application and reapplication to ensure optimal performance and appearance.

Before you order

• Have I thoroughly inspected the existing facade for structural issues, rot, or water damage?
• Do I understand the existing wall assembly and how the new cladding will integrate?
• Have I chosen a thermally modified wood species and profile that suits my aesthetic and functional needs?
• Is the chosen layout (horizontal/vertical) appropriate for the architectural style?
• Have I accurately calculated the required material quantities, including a waste factor?
• Are the appropriate fasteners and flashing specified for the installation?
• Is the substructure adequate, or does it need to be repaired or replaced?
• Have I decided on a finish (or no finish) and understood the long-term maintenance implications?

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.

Questions to help you decide

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