Rainwater Pillow Bladder FAQs

Our rainwater bladder tanks feature a pillow-style flexible design made from reinforced industrial-grade PVC. The tank remains flat when empty for easy transport and installation, then gradually inflates as it fills with water. Once filled, the water pressure naturally shapes the bladder into a stable and fully supported storage system. No rigid frame or structural support is required.

No. The tank is completely self-supporting when filled with water. Unlike rigid tanks, the internal water pressure provides full structural stability, meaning no steel frame, timber base, or external support is required.

We offer a wide range of standard sizes from 1,000L up to 40,000L. Custom sizes and shapes are also available to suit your available space, access conditions, and water storage requirements.

👉 Need a different capacity? View the complete Fleximake Pillow Tank range here: https://fmestore.com.au/product/pillow-type-rainwater-bladder-tanks/

Yes. We offer two material grades:
• Potable Grade – Certified to AS/NZS 4020 standards for drinking water, cooking, and personal use.
• Non-Potable Grade – Suitable for garden irrigation, washing cars, livestock, and general water storage.

Yes. Our tanks are manufactured from heavy-duty reinforced PVC, designed specifically for Australian conditions. They are UV resistant, weather resistant, and suitable for long-term outdoor or concealed installation.

All rainwater bladder tanks are supplied with standard plumbing fittings designed for easy connection to Australian rainwater systems:
• Inlet (Fill Size): 90mm or 100mm – compatible with standard roof downpipes for direct rainwater collection.

👉 Need a different fitting size or custom connection? Please contact us – we can customise inlet and outlet fittings to suit your specific project requirements.

Outlet (Discharge Size): 25mm or 32mm BSP fitting – suitable for pump connection, garden irrigation, water transfer, or plumbing integration.
• 25mm – Best for standard garden hoses, drip irrigation, and household pressure pumps.
• 32mm – Best for high-flow irrigation, farm use, gravity-fed systems, and fast filling.

💡 Tip: If you're unsure, choose 32mm – you can always reduce down to 25mm with an adapter available at any hardware store.

Yes. We specialise in custom-made bladder tanks for unique spaces and industrial applications. We can customise inlet/outlet sizes, fitting positions, dimensions, shapes, and material grades.

To request a custom tank, please provide:
• 📏 Dimensions (Length × Width × Height/Depth) of available space
• ⚙️ Fill configuration – Bottom Fill / Side Fill / Top Fill
• 🔩 Fittings required – inlet/outlet sizes and quantities
• 💧 Material type – Potable (drinking water) or Non-Potable
• 📸 Site photos (strongly recommended for accurate design)

👉 Contact us for a custom quote.

We offer three main inlet options:
• Top Fill – Simplest DIY option. Connect directly to a downpipe for easy rainwater harvesting. No plumber typically required.
• Bottom Fill – Best for permanent or concealed installations (e.g., under-house systems). Provides clean plumbing layout with hidden pipework. Professional installation recommended.
• Side Fill – Ideal for retrofit installations or tight access areas where plumbing runs need flexibility. Requires diverter, 50mm hose, and non-return valve. Licensed plumber required in most states.

👉 If you are unsure, Top Fill is the easiest and most common option for residential installations.

The bladder tank connects to standard Australian downpipes (typically 90mm or 100mm PVC) using a direct connection or reducer fitting, depending on your setup. For Top Fill, you connect directly. For Side Fill, you will need a diverter and additional hose.

Yes, if you select the 90mm or 100mm inlet option. However, we strongly recommend installing a rainwater diverter or rain head even with direct-size inlets to prevent backflow during heavy rain. A diverter manages overflow and sends excess water down the downpipe while filling the tank at a manageable rate.

⚠️ In most Australian states, modifying downpipes requires a licensed plumber by law.

Yes. They are designed for simple installation and include all required fittings based on your selected configuration. Most installations only require basic tools.
• Top Fill – DIY-friendly. Most homeowners can install this themselves.
• Bottom Fill or Side Fill – Professional installation recommended.

One of the biggest advantages of a bladder tank is flexibility. The tank can be:
• Folded and rolled for transport
• Carried through narrow access points (doors, side passages, under-house entries)
• Unfolded and positioned on-site before filling

Once filled with water, it expands to its full size.

Important requirements:
• Ensure the folded tank can physically fit through access points
• Confirm there is enough flat space for final placement
• The surface must be clean and free from sharp objects

👉 If access is very limited, we can recommend a custom bladder design to suit your site.

For best performance:
• Surface must be flat and level
• Free from sharp rocks, debris, or protruding objects
• Suitable bases include concrete slabs or compacted soil

Yes, within limits:
• Maximum recommended slope: 250mm over 10 metres (25mm per 1 metre)
• For steeper slopes, a retaining wall or level platform is recommended
• Custom tie-down or webbing systems are available for challenging sites

Minor variations are acceptable, but the surface should be made as level as possible before installation. A properly level base ensures even water distribution and long-term durability. Use sand, fine gravel, or a geotextile underlay to create a smooth, level surface.

Bladder tanks are ideal for residential, commercial, and rural applications, including:
• Under houses (sub-floor rainwater storage)
• Under decks or patios
• Garages and sheds
• Narrow side passages
• Low-clearance or unused spaces
• Off-grid water storage systems
• Rural and farm water storage
• Commercial rainwater collection

Depending on your chosen material grade:
• Potable Grade – Drinking, cooking, showering, and all household uses
• Non-Potable Grade – Garden irrigation, washing cars, livestock watering, toilet flushing, and general outdoor use

Dispatch time: 5 – 14 working days from order date. Delivery takes an additional 2–7 business days depending on your location in Australia. By pre-ordering, you guarantee your spot in the next production batch.

Each tank comes with:
• The flexible rainwater bladder tank (rolled flat)
• Selected inlet and outlet fittings (based on your configuration)
• Repair patch kit
• Installation guide

In most residential cases with Top Fill installation, no council approval is required. However, approval may be required for:
• Complex plumbing installations
• Certain Side Fill systems (requires diverter and licensed plumber)
• Local council regulations (varies by region in Australia)

⚠️ In most Australian states, modifying downpipes or installing new plumbing requires a licensed plumber by law. We recommend checking with your local authority if unsure.

We specialise in custom-made bladder tanks. To request a custom tank, please contact us with:
• 📏 Dimensions (Length × Width × Height/Depth) of available space
• ⚙️ Fill configuration – Bottom Fill / Side Fill / Top Fill
• 🔩 Fittings required – inlet/outlet sizes and quantities
• 💧 Material type – Potable or Non-Potable
• 📸 Site photos (strongly recommended for accurate design)

👉 Contact our team for a custom quote.