Thermory Cladding Installation Guide

Thermory’s thermally modified wood cladding combines natural beauty with exceptional stability. Their installation systems are designed for speed, precision, and durability. Follow these guidelines for a flawless finish.

Why Thermory Cladding?

• Thermally Modified Wood: Increased dimensional stability and resistance to rot.
• Hidden Fix Systems: Clean, modern look with PaCS® Press-and-Click technology.
• Eco-Friendly: Sustainably sourced timber with long service life.

Installation Steps

1. Preparation

• Store boards indoors or under cover for 1–2 weeks before installation.
• Keep boards elevated and dry; avoid direct sunlight and moisture.
• Allow 5–10% extra material for waste.

2. Substructure

• Use ventilated battens (20–45 mm thick) spaced at 400 mm centres.
• Ensure continuous airflow behind cladding from top to bottom.

3. Fastening Options

• PaCS® Press-and-Click System:
  • Clip strips pre-mounted on rails for fast, hidden installation.
  • Boards snap into place; easy removal with a special key.
• B1-1 & T-6 Clips:
  • Stainless steel clips for grooved boards.
  • Maintain 4–6 mm gaps for expansion.
• Visible Screws:
  • Use stainless screws with pre-drilled pilot holes.
  • Maintain 20 mm edge and 40 mm end clearance.

4. Expansion Gaps

• Leave ≥ 5 mm gaps between boards.
• Oversize pilot holes to allow thermal movement.

5. Finishing

• For natural silver-grey patina, no coating is required.
• To maintain warm tones, apply Cutek Extreme® oil and recoat annually.

6. Maintenance

• Clean with a soft brush and water.
• Avoid harsh chemicals or high-pressure washing.

Warranty Compliance

• Follow Thermory’s official installation manual.
• Do not glue or drill through foil finishes.

Keywords

Thermory cladding installation, PaCS hidden clip system, thermally modified wood cladding, Thermory maintenance guide, Cutek Extreme finish.

Overview: Thermo-Treated Timber Decking and Cladding

Thermo-treated (thermally modified) timber offers exceptional performance for outdoor applications, combining natural beauty with enhanced durability and stability. The thermal modification process uses only heat, steam, or pressure to alter wood at a cellular level, creating a chemical-free, high-performance material that resists rot, decay, and dimensional movement. With proper care, thermo-treated decking provides decades of reliable service while maintaining authentic wood character.

Understanding Thermal Modification

The thermal modification process involves heating wood to high temperatures in a controlled environment without using chemicals:

• Removes sugars and resins that attract fungi and insects
• Creates dimensionally stable timber with reduced moisture absorption
• No chemicals or hazardous substances used
• Results in rich brown colouration throughout entire board thickness
• Environmentally friendly alternative to pressure-treated or tropical hardwoods

Performance Advantages

Superior Stability

• Reduces dimensional movement by up to 50%
• Less expansion and contraction due to moisture changes
• Minimal warping, cupping, or twisting
• Maintains straight, level surfaces throughout service life

Enhanced Durability

• Achieves Durability Class 1 (25+ years) or Class 2 (15+ years) depending on species
• More resistant to rot, decay, and insect damage
• Thermo-ash comparable to tropical hardwoods with 25+ year lifespan
• Protection extends through entire board thickness

Additional Benefits

• Chemical-free process generates no hazardous waste
• Doesn’t accumulate heat like composites, feels pleasant underfoot
• Smooth, splinter-free surface
• Sourced from sustainably managed forests

Natural Weathering Process

• Rich brown colour from thermal modification; silver-grey from natural aging
• Surface fades to silver-grey starting immediately after installation
• With direct sunlight, may age to silver in as little as 6 months
• Wood ages unevenly so different sides discolour at different rates
• Colour change doesn’t affect durability or structural performance
• Quick power wash can restore wood toward original colour

Routine Maintenance

Regular Cleaning

• Sweep regularly to remove debris and prevent surface staining
• Clean with mild soap and water as needed
• Keep surface free of leaves, needles, and moisture-retaining debris
• Remove spills, organic matter, and standing water promptly

Stain and Surface Management

• Most stains from barbecue spills, beverages, and general use fade naturally
• Household chemicals, grilling stains, wine, and sauces can leave surface stains
• Light sanding removes silvery surface and restores original appearance
• Deeper scratches can be blended with light sanding
• Sanded areas will weather to match surrounding boards

Annual Tasks

• Inspect and tighten fasteners
• Check for damage or wear
• Ensure proper drainage and ventilation
• Maintain clearance around edges to promote airflow
• Remove vegetation growth promptly

Colour Preservation Options

Option 1: Natural Silver-Grey Patina

• Allowing wood to age naturally requires very little maintenance
• Simply keep deck clean and enjoy 25+ years of low-maintenance beauty
• More economical, eco-friendly choice
• Authentic weathered wood aesthetic

Option 2: Maintain Rich Brown Tones

• Apply UV-resistant penetrating oil annually to preserve darker tone
• For direct sun exposure, reapplication may be needed sooner
• Products like CUTEK Extreme provide deep penetration
• Reapplication typically required every 12-18 months depending on exposure
• Maintaining brown colour requires more time and effort

Protective Treatment Application

For best results, prefinish boards with penetrating UV protectant oil before or immediately after installation:

Initial Treatment

• Factory finishing strongly recommended to protect all 6 sides
• Initial coating allows wood to age evenly and protects from trapped moisture
• Factory finishing with penetrating oil helps reduce checking and cracking
• Apply to clean, dry, dust-free surfaces

Ongoing Maintenance

• Clean surface with wood brightening cleaner before oil application
• If power washing, use lowest setting and widest fan, wait 1 day before oiling
• Sand surface before first reapplication if needed
• For grey boards, use colourless oil without UV filter to preserve tone
• Reapply according to manufacturer recommendations

Long-Term Performance

Expected Lifespan by Species

• Thermo-ash: Durability Class 1, 25+ years (comparable to tropical hardwoods)
• Thermo-spruce: Durability Class 1, 25+ years
• Thermo-pine: Durability Class 2, 15+ years when properly maintained
• Premium Nordic species can exceed 30 years with proper care
• Quality manufacturers offer 20-year limited warranties

Performance Factors

• Quality of thermal modification process
• Proper installation and ventilation
• Regular cleaning and debris removal
• Environmental exposure levels
• Maintenance frequency
• Untreated softwoods degrade within few years; thermally modified versions last 15-25+ years

Installation Considerations

• Use thermally modified timber for substructure to match decking lifespan
• Follow manufacturer’s installation guidelines
• Ensure adequate ventilation beneath structure
• Proper installation ensures deck can withstand elements
• Consider hidden fixing systems for clean appearance

Maintenance Schedule Summary

Upon Installation

• Apply UV-protective oil if colour preservation desired
• Ensure proper drainage and ventilation

Ongoing (As Needed)

• Sweep and clean regularly
• Clean spills promptly
• Remove vegetation immediately

Annual Tasks

• Inspect and tighten fasteners
• Check for damage
• Reapply UV oil if maintaining brown colour (more frequently in high-sun areas)
• Verify clearance and airflow

Every 12-18 Months (If Preserving Colour)

• Clean surface thoroughly
• Light sand if needed
• Reapply UV-protective treatment

Cost-Benefit Analysis

• Higher initial investment than untreated timber
• Often more budget-friendly than tropical hardwood alternatives
• Significantly lower maintenance requirements
• No chemical treatments required throughout lifespan
• Exceptional durability makes it cost-effective long-term investment
• Reduces replacement and maintenance expenses

Best Practices Summary

• Thermo-treated boards don’t necessarily require surface treatment, but regular oiling refreshes appearance
• Clean regularly to prevent debris accumulation
• Choose maintenance approach based on desired aesthetic
• Apply UV treatments annually if preserving colour
• Maintain proper ventilation and clearance
• Follow manufacturer guidelines for optimal results

Need Help?

Thermo-treated timber offers the perfect balance of natural beauty, exceptional performance, and environmental responsibility—providing you with a low-maintenance outdoor space that lasts for decades. For product recommendations, treatment advice, or technical support, our experienced team is always on hand to assist. Contact us for tailored guidance to suit your project.