• Exterior Cladding Systems: Suitable for use on exterior Charred Timber weatherboards, shingles, shakes, plywood profiles, and architectural beams.
• Building Types: Applicable to residential and commercial timber-framed or engineered wood cladding designs.
• Environmental Conditions: Suitable for varied regional climates across New Zealand, including biologically challenging exterior microclimates, high moisture profiles, and coastal zones exposed to fresh or salt water splash.
• Pre-Installation and Post-Installation Coating: Can be applied as a single protective coat to all faces of the Charred Timber cladding prior to installation, with a second coat applied to the face surface once the initial coat has fully diffused.

Colour:

• Recommend applying CUTEK oil tinted with Punga colourtone in either single or double strength. Clear oil can be used to further protect the timber below the char whilst allowing the char to silver slightly due to exposure to UV.

• Acetylated Timber Exclusion: Not suitable for application on acetylated wood profiles.
• Ground and Water Immersion Restriction: Must not be used on surfaces in direct contact with the ground or designed for permanent water immersion.
• Moisture Content Cap: Cladding timber must be dry with a maximum moisture content of 17% prior to coating; higher moisture levels significantly delay penetration, causing the oil to remain tacky on the surface.
• Pre-existing Surface Barriers: Cannot be applied directly over active film-forming surface coatings (such as standard paints, acrylic stains, polyurethanes, or varnishes); previous coatings must be removed completely with mechanical abrasion or a suitable stripper prior to application.
• Environmental Exposure/Application Temperature: Requires 2–3 days of dry conditions post-application to facilitate proper oil diffusion. Application in cold weather thickens the oil and may lead to over-application; warming the oil in a sunny or warm area is necessary to enhance initial thinning and penetration.
• Application Standards: Mixing must achieve 1 can of CUTEK Colourtone per 5 litres of clear oil to secure even pigmentation. Application should utilise thin, uniform passes via a professional brush or paint pad.
• Internal and Food Surface Restrictions: Not suitable for food preparation or direct food contact surfaces. Not typically recommended for standard internal architectural linings due to potential faint green copper salt hues developing on light or white woods when unexposed to UV light.

CUTEK Extreme CD50, when specified, applied, and maintained in accordance with the manufacturer's technical documentation, will comply with or contribute to compliance with the following performance provisions of the New Zealand Building Code:

• Clause B2 DURABILITY: Performance B2.3.1(b) 15 years and B2.3.1(c) 5 years. By controlling liquid and gas phase moisture, the oil stabilises Western Red Cedar cladding to significantly extend timber service life and preserve structural integrity.  
• Clause F2 HAZARDOUS BUILDING MATERIALS: Performance F2.3.1. The fully cured coating system presents no health hazard to occupants or structural installers.  

Contribution to compliance:

• B2.3.1(b) & B2.3.1(c): CUTEK Extreme CD50 functions as a deeply penetrating timber stabiliser rather than a superficial surface film. The permanently mobile oil prevents systemic water ingress from degrading the natural cellular structure of Western Red Cedar. This internal moisture management directly counteracts wood structural defects—reducing splitting, warping, and cupping—to significantly increase the reliable service life of the external cladding system.  
• F2.3.1: Once fully absorbed and cured within the grain of the cladding timber, the product complies with regional safety handling benchmarks and poses no toxic risk to human health or surrounding occupational zones.

CUTEK penetrating oils have a 30-year proven track record of performance in the New Zealand climate and other severe environmental conditions globally. The underlying technology has undergone comprehensive testing by independent industry specialists in multiple international settings over the past three decades. 

• VOC Emission Level: ~ 250 g/L (ASTM 3960 framework).  
• Flash Point: 73°C (clear oil, ASTM D93) / 65C (Colourtone pigment pack).  
• Viscosity: ~27 cSt at ambient temp / ~ 18 cSt base profile.  
• Thermal Performance: Capable of withstanding continuous dry heat exposure up to 80° without experiencing molecular degradation or film cracking. 
• Sustainability: Eco-Partnerships: For every can of CUTEK Extreme CD50 sold in the New Zealand market, one tree is planted via an active reforestation program in partnership with One Tree Planted.

Maintenance Guidelines

• Inspection Intervals: Exterior vertical rough-sawn cladding profiles typically retain performance longer than horizontal components. Cladding surfaces should be inspected during regular house washing. Re-application is required when the surface no longer beads water or when significant colour fading occurs.
• Preparation: Normal maintenance requires washing down dirt, pollen, and environmental grime using a surface cleaner such as CUTEK Quickclean prior to recoating. Neglected or heavily silvered surfaces can be returned to the cedar's original freshly oiled appearance by processing with CUTEK Restore and high-pressure water washing prior to oil application.