Your Ultimate Visual Guide To Cedar Cladding Problems NZ

Wondering, “What’s wrong with my cedar cladding?” after seeing signs of damage? We’re here to help. While being a premium timber that’s highly resistance to rot, insects, and decay, cedar is still vulnerable to deterioration. This is especially the case when there’s been a lack of regular cedar maintenance.

So, if you’ve just moved into a property with cedar cladding or have had your cladding for a while and are noticing changes in its appearance, it’s important to get to the bottom of it now than later. This guide will make it easier for you as we have listed the five most common cedar cladding problems in NZ, with pictures to compare to what you see. We’ve also asked our experts to answer some of the biggest questions on these issues.

5 Of The Biggest Cedar Cladding Problems In NZ & How To Identify Them

When your cedar cladding is not maintained correctly, the first thing you’ll notice is its appearance. “It starts to look faded or light and anaemic, especially in north-facing exposed areas,” says Dryden WoodOil’s founder Jon Pearson to ArchiPro.

Apart from the visual aspect, when a stain begins to degrade, it permits moisture to penetrate the wood, resulting in cupping, warping, and splitting. “Oils and stains are designed to repel water.

Once a wall looks wet, that is, water doesn’t bead off it anymore, that’s when these sorts of products have deteriorated,” adds Jon.

As you read about the five common cedar cladding problems in New Zealand, you’ll notice that they all have a few common causes; high moisture content and exposure to the elements.

Dryden WoodOil can protect your cedar from both as it’s a water-repellent, non-filming timber protector. It’s a true migrating oil that migrates deep into the timber and protects it from the inside out.

As a result, issues like the ones below are greatly minimised, the life of your cedar cladding is extended, and it keeps looking beautiful for years to come!

1. Cupping, warping and splitting

How to identify:

You’ll see noticeable deformations, like cupping (when the edges of boards are higher than the centre and form a concave shape) or warping (twisting) of the cedar boards and clear surface splits.


What it looks like:

Here’s an example of a weatherboard that has been left for many years to fend for itself and, as a result, experienced heavy cupping.


What are the causes?

High moisture content, exposure to extreme temperature changes, and improper coating/sealing of the timber.

Featured: 4 Best Products for Cedar Maintenance in New Zealand.

2. Weathering

How to identify:

Your timber cladding will gradually lose colour and deteriorate from sunlight, rain, and wind exposure.


What does weathered cedar look like?


What causes weathering of cedar?

The sun, rain, and wind will gradually wear away the softer timber fibres of the cedar cladding, resulting in a loss of colour and texture. With New Zealand’s harsh sun and exposure to UV rays being particularly intense, the weathering process on your cedar cladding can accelerate.

3. Silvering

How to identify:
The cedar cladding loses its distinctive rich colour and takes on a silvery-grey hue caused by the sun’s UV rays.


What silvering on cedar cladding looks like:



What are the causes?
Coloured timber extractives are washed out (leaching), and the cedar structures get damaged by sunlight (photodegradation).

4. Mould and lichen development

How to identify:

Dark spots or green patches on your cedar cladding will indicate mould or lichen growth.


What it looks like:

Example of lichen growth on cladding.


What are the causes?
Damp and humid conditions create the perfect breeding ground for mould, lichen, and moss, as these contaminants thrive in moisture and warmth.

5. Decay and rot

Cedar cladding can last up to 50 years if properly maintained and coated with a high-quality protector like Dryden WoodOil. However, it will last only about 25 years without proper care and treatment. Click here to find out how to maintain your cedar cladding, so you keep your cedar looking its best for years to come.


How to identify cedar rot and decay:

Look out for soft, spongy spots on your cedar cladding, along with discolouration that will signal wood decay and rot


What rot and decay look like:


What causes cedar cladding to rot?

Improper coating and constant dampness are the culprits behind rot and decay on cedar cladding.

To find out how to fix your cedar cladding from these five problems, check out this guide:

Your Complete Guide On How To Restore Cedar Cladding

FAQs On Cedar Cladding Problems:

Your Questions Answered By The Experts

Dryden’s woodcare experts answer some of the most frequently asked questions on cedar cladding problems in New Zealand. Western red cedar cladding maintenance includes

How long does cedar cladding last?

Cedar cladding can last up to 50 years with proper care and maintenance. Maintenance for western red cedar cladding, the type of cedar commonly used here in NZ, includes applying a premium water-repellant finish like Dryden WoodOil and following it up with a soft wash annually.

Can I prevent cupping and warping?

Yes! Cupping, warping and splitting are all caused by high moisture content and exposure to extreme temperature change. So you can prevent all this by properly sealing or coating with a premium finish like Dryden WoodOil, which is a water-repellent, non-filming timber protector.

What type of finish should I use to protect against weathering?

Transparent or semi-transparent stains are popular because they preserve the cedar’s natural appeal. Dryden WoodOil, a water-repellent timber protector, is an optimal choice. It penetrates deep, reducing excessive warping, cupping, and splitting.

“Stains contract and expand at a different rate to the timber because they are operating separately; they are on the surface of the product rather than a part of the timber. Eventually, with these different rates of contraction and expansion caused by temperature variations during a normal day, they delaminate, crack and peel, and that’s when they allow moisture into the timber and stop working as the waterproof barrier they were designed to be,” says Dryden’s Jon Pearson to ArchiPro magazine, adding;

“Dryden WoodOil, in contrast, exists within the timber, rather than on its surface, so in the heat and cold, it contracts and expands with the timber, working as one entity rather than two. “The benefit of this is that when this product starts to age, the differences are only cosmetic. Oils retain their integrity over time, still working as they were designed to. What changes is their sacrificial aesthetic colour quality.”

What’s My Current Cedar Coating? An Easy Guide To Checking The Coating On Your Cladding

Final Thoughts on Cedar Cladding Problems in NZ:


Here are a few key points to take away from this guide;

  • Cedar cladding can last up to 50 years with proper care and maintenance, which involves coating it with a premium finish like Dryden WoodOil annual soft washes.
  • Common cedar cladding problems include; cupping, warping, splitting, weathering, silvering, mould/lichen development and decay/rot.
  • These issues are caused by either high moisture content or exposure to elements.
  • To prevent these issues and maintain your cedar’s appearance for years, use a water-repellent timber protector like Dryden WoodOil and regularly check and carry out maintenance.
  • Transparent or semi-transparent stains are popular choices to preserve the cedar’s natural appeal.

Click here to find out how to restore your cedar cladding to its former glory. Bookmark this post so you know what to do the next time you notice something off with your cedar cladding. See our other resources on timber care, or explore our products that are specifically made for NZ conditions. Good luck!