Which Geotextile Fabric Do I Need? A Simple Guide to Bidim Green
- Di McQueen-Richardson
- Aug 7
- 4 min read
If you know you need geotextile fabric but aren't sure which size or type to buy, you're certainly not alone.
Geotextile is used in everything from small backyard drainage jobs to retaining walls and major landscaping projects. The right choice depends on what you're trying to achieve, the size of the area, and how the fabric will be installed.
For many common landscaping and drainage applications, Bidim Green Filterwrap provides a practical solution.
What is Bidim Green Filterwrap?
Bidim Green Filterwrap is a nonwoven geotextile fabric designed to allow water to pass through while helping prevent surrounding soil and fine particles from migrating into drainage aggregate.
In simple terms, it helps keep your soil and drainage materials where they're supposed to be while allowing water to move through the system.
This makes it particularly useful for filtration and separation applications.
What can Bidim Green be used for?
Depending on the project and installation requirements, Bidim Green Filterwrap can be suitable for applications such as:
Garden and landscape drainage
Subsoil drainage
Drainage trenches
Retaining wall drainage
Separation of soil and aggregate
Gravel drainage areas
Landscaping projects
Civil and construction applications
For engineered or specialised projects, always check the relevant technical specifications before selecting a product.
Which Bidim Green roll size should I choose?
BelloScapes Supply Co. stocks Bidim Green Filterwrap in four roll widths, all supplied in 50-metre lengths.
600mm × 50m — 30m²
The narrowest roll in our range can be a practical choice for smaller or narrower applications, where a wider roll would create unnecessary excess material.
Because it provides 30m² of material, it's also a useful option for smaller domestic projects.
1.0m × 50m — 50m²
The 1-metre roll provides 50m² of coverage and offers a versatile size for a range of landscaping and drainage applications.
It can be particularly convenient when the dimensions of the project suit a metre-wide fabric.
1.2m × 50m — 60m²
At 1.2 metres wide, this roll provides 60m² of geotextile.
The additional width can reduce the need for multiple narrower sections in appropriate applications, making it a useful option for larger drainage and landscaping projects.
2.0m × 50m — 100m²
The largest Bidim Green Filterwrap roll currently stocked by BelloScapes provides 100m² of material.
It's particularly suited to larger areas where the wider fabric can help reduce the number of separate runs required.
Should I simply choose the roll with the closest square-metre coverage?
Not necessarily.
This is an important point.
Imagine you need to cover an area of approximately 45m². It might seem obvious to choose whichever roll provides the closest total area.
But the dimensions of the project matter too.
A wider roll may allow you to cover an area with fewer joins, while a narrower roll might suit a long drainage trench much better.
You also need to consider any material required for overlaps, wrapping, edges and installation.
That's why it's better to think about both the total area and the shape of the project rather than choosing purely by square metres.
How do I calculate the area I need?
For a straightforward rectangular area, measure:
Length × Width = Area in square metres
For example, an area measuring 10 metres long and 4 metres wide has a basic area of 40m².
However, that doesn't automatically mean that exactly 40m² of geotextile will be sufficient.
The way the fabric needs to be positioned or wrapped can increase the amount required.
For irregular areas, it can help to divide the project into smaller rectangles, calculate each area separately and then add them together.
Which geotextile should I use behind a retaining wall?
Geotextile is commonly incorporated into retaining-wall drainage systems to help separate soil from drainage aggregate while allowing water to move through.
However, a retaining wall is a complete drainage and structural system, not simply a piece of fabric behind a wall.
The appropriate drainage design will depend on factors such as the wall, soil, site conditions, water movement and construction method.
For substantial or engineered retaining walls, follow the project specifications and obtain professional advice where required.
We'll cover retaining-wall drainage in much more detail in another article in this series.
What about a backyard drainage trench?
This is one of the more common domestic applications.
If you're installing drainage to deal with a wet section of the garden, excess groundwater or water accumulating around a landscaped area, geotextile may be used as part of the drainage system to help prevent soil from contaminating the drainage aggregate.
Again, width becomes important.
A long, relatively narrow trench may require a completely different amount and roll configuration from a broad landscaped area, even if both projects have a similar total square-metre measurement.
Do I need pins to hold geotextile in place?
Depending on the installation, geotextile pins can help hold fabric securely in position during installation.
BelloScapes stocks geotextile pins alongside our fabric range, so you can purchase the fabric and appropriate installation accessories from the same local supplier.
The number and type of fixings required will depend on the application and installation method.
Can BelloScapes help me work out how much I need?
Yes.
We've developed a BelloScapes Product Calculator specifically to make this easier.
Rather than simply calculating square metres, our aim is to let you enter your project dimensions and help determine the most practical quantity from the actual Bidim Green roll sizes we stock.
That should make it much easier for homeowners and tradies to work out what to order—and help reduce unnecessary excess material.
Where can I buy Bidim Green near Bellingen?
BelloScapes Supply Co. stocks Bidim Green Filterwrap locally in Bellingen NSW, along with drainage, erosion and sediment-control products, fixings and accessories.
Our range is available to homeowners, DIY customers, landscapers, builders and other trades, so you don't need to be working on a major commercial project to purchase specialist geotextile products.
Order online and arrange click & collect in Bellingen, or contact us about local delivery.
Still not sure which size you need?
Don't guess.
Measure your project as accurately as possible and consider not only the total square metres but also the width, length and way the material needs to be installed.
Then explore the Bidim Green sizes available from BelloScapes or contact us if you need help understanding the options.
For detailed technical specifications and installation requirements, refer to the manufacturer's technical information.
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