Do You Need Protection Fleece for an Attenuation Tank Geomembrane?

What Is Protection Fleece?

Protection fleece is a heavy-duty non-woven geotextile installed to help protect an impermeable geomembrane from punctures, abrasion and damage during installation and backfilling.

When used as part of an attenuation tank encapsulation system, the fleece acts as a cushioning layer between the HDPE membrane and surrounding materials, helping to preserve the integrity of the waterproof barrier.

Why Is Protection Fleece Important?

Although HDPE geomembranes are extremely durable, they can still be damaged by sharp aggregates, construction debris or point loading during installation.

Installing a suitable protection fleece helps:

• Reduce the risk of punctures
• Protect the membrane during backfilling
• Provide a cushioning layer around attenuation crates
• Improve the long-term durability of the lining system
• Reduce the likelihood of costly repairs

Should Protection Fleece Be Installed Above and Below the Membrane?

In many attenuation tank applications, protection fleece is installed both beneath and above the impermeable geomembrane.

The lower layer helps protect the membrane from the prepared formation, while the upper layer provides additional protection from backfill materials and construction activities.

Project-specific designs should always be followed, but using protection fleece on both sides of the membrane is common practice where enhanced protection is required.

Is 300gsm Protection Fleece Suitable?

A 300gsm non-woven geotextile is widely used as a protection fleece for attenuation tank encapsulation systems.

Its robust construction provides excellent cushioning while remaining permeable, allowing it to protect the membrane without affecting the overall waterproofing function of the HDPE liner.

Can You Install an HDPE Geomembrane Without Protection Fleece?

Some projects may not require protection fleece, depending on the specification and site conditions.

However, where there is a risk of mechanical damage during installation or backfilling, incorporating a suitable protection layer is often considered good practice and may help extend the service life of the membrane.

Typical Attenuation Tank Build-Up

A simplified impermeable attenuation tank installation may include:

1. Prepared formation                                                                               
2. Modular attenuation crates
3. HDPE geomembrane
4. 300gsm protection fleece
5. Backfill material in accordance with the project specification

Frequently Asked Questions

Does protection fleece make the attenuation tank waterproof?

No. The waterproof barrier is provided by the HDPE geomembrane. The protection fleece is designed to help safeguard that membrane from damage.

What weight protection fleece is commonly used?

A 300gsm non-woven geotextile is commonly used for protecting HDPE geomembranes in attenuation tank applications.

Can I use a standard 100gsm geotextile instead?

Lighter geotextiles are generally intended for separation and filtration rather than membrane protection. Where protection against puncture is required, a heavier-duty 300gsm product is often the preferred choice.

Do I still need jointing tapes?

Yes. Where membranes require overlapping or detailing around penetrations, suitable jointing tapes and accessories should be used in accordance with the installation requirements.

Complete Your Attenuation Tank Lining System

For a complete impermeable lining solution, consider the following products

• 0.6mm HDPE Geomembrane Range
• 1.0mm HDPE Geomembrane Range
• 300gsm Protection Fleece Range
• Double-Sided Butyl Jointing Tape
• Single-Sided Jointing Tape
• Top Hat Units

Choosing the correct roll size can also help reduce installation time and ensure consistent coverage across the arena base.

If you require assistance selecting the correct specification or need pricing for project quantities, our team is happy to help.

Contact us on 03338803558  or  info@drainageandcivilsdirect.co.uk and we’ll point you to the right product and get it delivered fast.