How do you stop cedar roofs changing colour?

Cedar roofs are renowned not only for their aesthetic appeal but also for their durability and resistance to the elements. However, without proper maintenance, the beautiful colour of cedar can change over time due to natural and environmental factors. Understanding why this happens and how to manage it is crucial for maintaining the roof’s appearance and longevity.

The Science Behind Colour Changes in Cedar

Cedar wood contains natural oils and tannins that provide a rich colour and protect against rot and insect damage. Over time, these natural compounds slowly break down due to exposure to ultraviolet (UV) light from the sun and moisture, leading to the familiar silver-grey patina that many associate with aged cedar. This colour change is a natural part of the wood’s ageing process but can be accelerated by environmental factors.

Factors Accelerating Colour Change

Several factors can accelerate the ageing process of cedar roofs:

Sunlight Exposure: UV rays can degrade the wood fibres over time, leading to a loss of the original colour.

Moisture: Rain, snow, and humidity can leach the natural oils and tannins from cedar, hastening the greying process.

Microbial Growth: Moss, algae, and fungi thrive on moist wood, causing additional moisture retention and potentially leading to wood rot if not addressed.

The Impact of Leaves, Moss, and Algae

Leaves, twigs, and other debris can trap moisture on the roof, creating an ideal environment for moss and algae to grow. This not only affects the aesthetic appearance of the roof but can also lead to structural damage if not cleaned regularly. Moss and algae hold moisture against the roof, which can penetrate the cedar shakes or shingles and cause them to swell and crack.

Preservation Techniques to Maintain Colour

To mitigate these effects and preserve the natural colour of cedar roofs, consider the following strategies:

1. Regular Cleaning: Remove leaves, twigs, and other debris from the roof to prevent moisture retention and microbial growth. This should be done gently to avoid damaging the wood.

2. Control of Microbial Growth: Treat the roof with solutions designed to kill and prevent the growth of moss, algae, and fungi. Products containing copper or zinc compounds are effective because they provide long-term protection against microbial growth.

3. Application of Protective Coatings: Use specially formulated preservatives that penetrate the wood and replenish the natural oils lost over time. These products often contain UV blockers and moisture repellents that help maintain the colour and integrity of the cedar.

Choosing the Right Products

When selecting products for preserving cedar roofs, it’s essential to choose ones that are compatible with cedar and will not cause further damage. Products like Amteco TWP 200 and others specifically designed for cedar can provide the necessary protection while enhancing the wood’s natural beauty. It’s also important to follow the manufacturer’s instructions on application intervals to maintain effective protection over the years.

By understanding the factors that affect cedar roofs and taking proactive steps to counteract these effects, you can ensure that your cedar roof remains beautiful and functional for many years to come. Regular maintenance, coupled with the right preservation techniques, will not only keep your cedar roof looking its best but also extend its lifespan, making it a worthwhile investment for any homeowner.