Choosing the wrong coir log size may seem like a minor mistake until one heavy rainy day washes your entire site downstream. Most landscapers make this mistake, which causes all their investments to go in vain. Whether stabilising a slope or protecting a waterway, the right log size promises not only better performance but also cost efficiency and long-term stability.

But with multiple sizes available, you need to be aware of each size and variant to make the perfect choice for your project. Larger logs for

In this guide, we’ll break down the common sizes of coir logs, factors that influence your choice, and practical tips to help you decide.

Factors to Consider When Choosing the Right Size

1. Terrain and Slope

Coir logs are a popular choice to stabilise soil in slopes and embankments. The steepness of your project site plays a big role in choosing the right coir log size. If the permeability of the log doesn’t match the water flow rate, water may start pooling and flooding, failing the project.

For slopes or embankments with a larger inclination, logs like 300mm or 400mm are ideal. They offer good permeability for water to flow through at high rates.
For gentler slopes or flat terrain, 200mm logs are often enough and more cost-effective. Going for a lighter variant can prevent you from spending unnecessarily than needed.

The length of the log needs to be decided based on the area of the contour that needs to be covered.

2. Water Flow and Exposure

Is your project near a fast-flowing stream, river, or stormwater channel? Then water velocity becomes a key factor. The weave of the log should be able to withstand the flow pressure it faces. If the weave isn’t strong enough, the log will be discarded faster.

High-flow areas require more robust logs, like 400mm or 500mm. They can withstand pressure and anchor firmly in place. Go for a log that comes with predrilled holes if possible.
Low-flow or temporary runoff zones usually do well with 200mm–300mm logs.

3. Application Type

Believe it or not, the environment also impacts the right size can vary depending on where you’re installing the log:

Riverbanks and stream edges – Opt for 300mm or 400mm logs for better water resistance and erosion protection. We recommend you go for the 3m long variant, as you can cover long distances with fewer logs.
Construction site drains, culverts or swales – Use 300mm logs for sediment control and filtration.
Garden decoration and raised garden bed creation – 200mm logs are often enough and easier to install. For raised garden beds, 200mm will be easy to move from place to place if needed.

4. Site Constraints and Accessibility

Not all sites are the same; some sites are easy to access, while some are hard. Each site has unique formations and environments, and it has an impact on choosing the right coir log:

Smaller logs are easier to handle and transport. If your site has narrow access paths, tight curves, or limited working space, a less weighing log will help you in the installation process.
You can join several logs together with coir twine or rope to fit your unique contours of the site.

5. Labour and Budget

Don’t just consider the price of the log; consider the total cost of installation. Sometimes the cheaper option may cost you more in total than the expensive option. Here’s how different sizes may cost you:

Larger logs like 3m x 300mm can cost nearly double as smaller variants, but require fewer logs to cover more area. If you require higher erosion control needs, you require more manpower and anchoring equipment (timber stakes or steel pickets).
Smaller logs can be installed faster and with fewer materials, reducing overall cost and labour effort.

Final Tips to Wrap Up

Now you are well aware of how to choose the right size of coir log, let’s wrap up the blog with some final tips for you who are on the verge of buying.

Inspect the site conditions or consult with an engineer if unsure
Factor in the expected lifespan and maintenance needs
Buy in bulk for larger projects to save on costs
Choose a reputable supplier with proven experience and reliable delivery

Talking about reputable suppliers, HEIGER Australia is a trusted coir log supplier in Australia, offering a wide range of premium coir logs in Australia in multiple diameters. Getting ready for projects, either big or small, is easy with our comprehensive range of logs.

Need help choosing the right size? Contact our team today for expert advice tailored to your site conditions.

If you are looking for other erosion control products, explore other products we offer like Coir mesh, Coir blankets, Jute matting, Jute mesh, and Silt Fences.