Shadowclad: What to Watch Out For and How to Maintain It

Shadowclad is a popular choice for exterior cladding in New Zealand homes, particularly in modern and contemporary designs. Known for its natural timber appearance, it offers a versatile and aesthetically pleasing finish. However, like any building material, Shadowclad comes with its own set of challenges, particularly in New Zealand’s diverse and often harsh climate. At Red LBP Building Inspections, we frequently encounter issues related to Shadowclad during our inspections. In this blog, we’ll discuss what to watch out for with Shadowclad, the best ways to maintain it, and why it can be problematic in New Zealand.

What is Shadowclad?

Shadowclad is a plywood-based cladding system produced by Carter Holt Harvey. It’s widely used across New Zealand for both residential and commercial buildings. The product is available in a variety of finishes, including natural, grooved, and textured, allowing for a range of design possibilities. It’s favoured for its affordability, ease of installation, and the ability to be painted or stained to suit different architectural styles.

Common Issues with Shadowclad

While Shadowclad has its benefits, there are several issues that homeowners and builders need to be aware of:

1. Moisture Ingress: One of the most significant problems with Shadowclad is its vulnerability to moisture. If not properly installed and maintained, Shadowclad can absorb water, leading to swelling, warping, and eventually rot. This is particularly problematic in areas of New Zealand that experience high rainfall or humidity.
2. Inadequate Sealing: The edges and joints of Shadowclad sheets are especially susceptible to water ingress if they are not adequately sealed. Poor sealing can lead to delamination, where the layers of plywood begin to separate, compromising the structural integrity of the cladding.
3. UV Exposure: Over time, exposure to UV rays can cause the timber to deteriorate, leading to cracking and fading. This not only affects the appearance of the cladding but can also make it more prone to moisture damage.
4. Installation Errors: Many of the issues we encounter with Shadowclad arise from improper installation. This includes insufficient gaps between sheets, incorrect flashing details, and inadequate ventilation. These mistakes can exacerbate moisture problems and reduce the lifespan of the cladding.

Maintaining Shadowclad

To ensure your Shadowclad cladding remains in good condition, regular maintenance is essential. Here’s how you can protect your investment:

1. Regular Inspections: Conduct regular inspections of your Shadowclad cladding, particularly after heavy rain or storms. Look for any signs of swelling, cracking, or paint peeling. Early detection of problems can prevent more significant issues down the line.
2. Repaint or Restain: To protect Shadowclad from UV damage and moisture, it’s important to keep the cladding well-coated with paint or stain. Repainting or restaining every few years can help maintain its appearance and integrity. Be sure to use products that are specifically designed for timber cladding.
3. Seal Joints and Edges: Ensure that all joints, edges, and penetrations in the cladding are properly sealed. Use high-quality sealants to prevent water ingress, and check these areas regularly for any signs of deterioration.
4. Ensure Proper Drainage: Proper drainage is crucial for preventing moisture buildup behind the cladding. Make sure that your home’s design includes adequate flashing and that water can flow away from the walls easily.
5. Ventilation: Good ventilation behind the cladding can help reduce moisture levels and prevent condensation. Check that your home’s design includes sufficient airflow to keep the area behind the cladding dry.

Why Shadowclad is Problematic in New Zealand

New Zealand’s unique climate, characterised by high humidity, frequent rainfall, and strong UV exposure, can be particularly harsh on timber cladding like Shadowclad. Homes in coastal areas are especially vulnerable due to the combination of salt air and moisture. Additionally, the building boom in recent years has led to some homes being constructed with less attention to detail, resulting in installation errors that exacerbate the material’s inherent weaknesses.

At Red LBP Building Inspections, we’ve seen the consequences of neglected or poorly installed Shadowclad. While it can be an attractive and cost-effective option, it requires careful installation and regular maintenance to perform well in New Zealand’s challenging environment. By staying vigilant and addressing issues promptly, you can ensure your Shadowclad cladding remains in good condition for years to come.