Thermally Modified Radiata Pine Cladding

Thermally Modified Radiata Pine Cladding

This product is a special order item. Please speak to us concerning your needs.

Overview

Thermally Modified Radiata Pine is a premium external cladding timber that combines the natural beauty of sustainably grown Radiata Pine with the enhanced performance achieved through thermal modification. Using only heat and steam, the timber is modified without the use of chemical preservatives, significantly improving its durability, dimensional stability and resistance to moisture.

The result is a lightweight, stable and highly durable timber that is ideally suited to modern rainscreen cladding systems and architectural façades. Its clean appearance and excellent machining characteristics make it a popular choice for both residential and commercial developments.

Appearance

Thermally Modified Radiata Pine has a warm golden-brown to rich caramel colour immediately after manufacture.

The timber typically features:

• Straight grain.
• Fine, even texture.
• Small, sound knots depending on the grade supplied.
• A clean, contemporary appearance.

Compared with many traditional softwoods, Radiata Pine offers a more uniform finish while still retaining the warmth and natural beauty of real timber.

What to Expect if Left Untreated

Thermally Modified Radiata Pine does not require preservative treatment for external durability.

If left untreated:

• The rich brown colour gradually fades.
• The timber naturally develops an attractive silver-grey patina.
• UV exposure affects colour only and does not reduce durability.
• Weathering rates vary depending on exposure to sunlight and prevailing weather.

Many architects deliberately leave the timber untreated to achieve a natural weathered appearance.

Recommended Treatments

Treatment is optional and depends entirely on the desired appearance.

To retain the original colour

We recommend using a quality UV-resistant exterior coating such as:

• Osmo UV Protection Oil
• Sansin SDF
• Teknos Exterior Wood Coatings
• Remmers Exterior Timber Coatings
• Sikkens Cetol System

These products help preserve the timber's natural colour while reducing UV weathering.

For a natural silver-grey appearance

No treatment is required.

Alternatively, pre-weathering coatings can be applied where a consistent silver-grey finish is preferred from the outset.

Durability

Thermal modification significantly improves the durability of Radiata Pine.

Durability Class: Class 2 – Durable

The process reduces the timber's ability to absorb moisture, making it highly resistant to fungal decay and ideal for external cladding applications.

With correct detailing and installation, an above-ground service life of 30 years or more can be expected.

Density & Weight

Approximate Density:

400–450kg/m³

Thermally Modified Radiata Pine remains lightweight, making it particularly easy to handle and install.

Benefits include:

• Faster installation.
• Reduced structural loading.
• Easy handling on site.
• Suitable for larger profile cladding boards.

Stability

One of the biggest advantages of Thermally Modified Radiata Pine is its outstanding dimensional stability.

The thermal modification process greatly reduces moisture movement, resulting in:

• Minimal expansion and contraction.
• Reduced cupping.
• Reduced twisting.
• Excellent long-term performance.
• Ideal for shadow gap and rainscreen cladding systems.

Compared with untreated softwood, seasonal movement is significantly reduced.

Recommended Fixings

Always use corrosion-resistant fixings for external cladding.

Recommended

? A2 Stainless Steel screws or ring-shank nails for inland installations.

? A4 Stainless Steel fixings for coastal or highly exposed environments.

Pre-drilling is recommended near board ends to ensure a neat finish and minimise the risk of splitting.

Typical Applications

Thermally Modified Radiata Pine is suitable for:

• Contemporary homes.
• Residential developments.
• Commercial buildings.
• Garden rooms.
• Garden offices.
• Extensions.
• Apartment buildings.
• Soffits.
• Fascias.
• Architectural feature walls.
• Timber frame construction.

Advantages

• Thermally modified without chemicals.
• Lightweight and easy to install.
• Excellent dimensional stability.
• Naturally durable.
• Attractive warm colour.
• Fine, uniform grain.
• Reduced movement compared with untreated softwood.
• Excellent machining characteristics.
• Suitable for modern architectural cladding.

Things to Consider

Like all natural timber, Thermally Modified Radiata Pine will weather naturally if left untreated.

Customers wishing to maintain the original rich brown appearance should apply a suitable UV-resistant coating and maintain it in accordance with the coating manufacturer's recommendations.

Thermal modification also makes the timber slightly more brittle than untreated Radiata Pine, so care should be taken during machining and installation. Pre-drilling is recommended, particularly near board ends.

Good to Know

Thermally Modified Radiata Pine is becoming an increasingly popular alternative to Thermowood Ayous and Thermowood Redwood.

Compared with Thermowood Redwood:

• More consistent appearance.
• Finer grain.
• Fewer prominent knots (depending on grade).
• Excellent dimensional stability.
• Similar durability.
• Lightweight and easy to install.

Compared with Thermowood Ayous:

• More visible natural grain.
• Slightly more character.
• Similar thermal modification benefits.
• Excellent value for money.

For customers looking for a modern timber cladding with a clean, consistent appearance and excellent long-term performance, Thermally Modified Radiata Pine is an outstanding choice.

Sustainability

Radiata Pine is one of the world's most sustainable commercial timber species due to its rapid growth and efficient plantation management. When sourced from FSC® or PEFC certified forests and combined with a chemical-free thermal modification process, it provides an environmentally responsible solution for external cladding.

Lanlee Performance Guide

Frequently Asked Questions

Does Thermally Modified Radiata Pine need treating?

No. Thermal modification provides excellent durability without the need for preservative treatment. Coatings are only recommended if you wish to retain the original warm brown colour.

Will Thermally Modified Radiata Pine turn grey?

Yes. Like all natural timbers exposed to UV light, it will gradually weather to an attractive silver-grey patina if left untreated.

Is Thermally Modified Radiata Pine suitable for coastal locations?

Yes. When installed with A4 stainless steel fixings and in accordance with good cladding practice, it performs very well in coastal and exposed environments.

Is Thermally Modified Radiata Pine environmentally friendly?

Yes. Radiata Pine is a rapidly renewable plantation-grown timber, and the thermal modification process uses only heat and steam, making it an environmentally responsible choice for external cladding.

Lanlee Recommendation

Thermally Modified Radiata Pine is an excellent option for customers looking for a stable, lightweight and sustainable timber cladding with a clean, contemporary appearance. Its fine grain, excellent dimensional stability and enhanced durability make it suitable for a wide variety of residential and commercial projects.

It offers many of the performance advantages of premium thermally modified timbers while providing exceptional value for money. Whether you're cladding a modern extension, a garden room or a large architectural development, Thermally Modified Radiata Pine delivers long-lasting performance with the warmth and beauty that only natural timber can provide.