If you need to prepare a base for your poly tank, it is strongly recommended that this is completed before delivery.

⚠️ Important: Always refer to the manufacturer’s official installation guide for your specific tank model. Manufacturer specifications override any general guidance provided below.

• QTank Base Preparation guide (PDF)

General Requirements (All Poly Tanks)

• The base must be solid, level and flat in all directions.
• The base must support the full weight of the tank when filled (water weighs approximately 1kg per litre).
• Remove any tree roots, rocks or sharp objects that could damage the tank base.
• Tanks expand and contract slightly as water levels rise and fall. Allow sufficient clearance around the tank (see below).
• If positioning against a wall, construct the base with a slight fall away from the structure to prevent water pooling.
• The tank must not be buried unless specifically designed for underground use.
• Always ensure overflow discharge does not undermine the tank pad.

Tank Pad Dimensions

Round Poly Tanks

For round poly tanks (including QTank models):

• The tank pad must be at least 600mm larger than the tank diameter.

Example:

• Tank diameter = 1000mm
• Minimum base diameter → 1600mm

This provides stability and allows for natural tank expansion.

Additionally:

• Maintain at least 100mm clearance from walls, fences, trees or fixed objects.
• If using charged lines or pipework near a wall, allow sufficient clearance for expansion.

Slimline Poly Tanks

For slimline-style tanks:

• The tank pad must be a minimum of 100mm wider and longer than the tank dimensions.

Example:

• Tank length = 2000mm → Base minimum 2100mm
• Tank width = 500mm → Base minimum 600mm

Maintain at least 100mm clearance from fixed objects to allow for expansion.

Base Material Options

Concrete Base (⭐Recommended)

• Must be level and flat in all directions.
• Ideal thickness: 100mm (10cm).
• Use reinforcing mesh for additional strength.
• Allow approximately 7 days curing time before placing the tank on the slab.

Crusher Dust / Compactable Material Base

• Must be level and flat in all directions.
• Use high-quality compactable material free of rocks or sharp objects.
• Thoroughly compact the base.
• The outside edge of the base should be supported (e.g. retaining edge, pavers or concrete border) to prevent erosion over time.
• Ensure overflow water cannot wash away or undermine the pad.

Crusher dust bases are not recommended for sloping or unstable ground without proper preparation.

Tank Stands

If installing on a raised stand:

• The stand must be engineered to support the full weight of the tank when full.
• Hardwood decking boards should have gaps no greater than 25mm.
• Seek professional advice before constructing elevated stands.

Warranty Notice

A correctly constructed base is critical to tank performance and longevity.

Most manufacturers (including QTank) state that damage caused by an unstable, undersized, or poorly constructed base may void warranty.

When in doubt, consult the manufacturer directly or obtain written confirmation before installation.

If you are installing a Kingspan AQUAPLATE® steel tank, it is critical that the tank pad is constructed correctly before delivery.

⚠️ Important: Kingspan’s Tank Base Preparation Guide (PDF) must be followed. Failure to comply may void warranty and may result in redelivery fees if the pad is deemed non-compliant at time of delivery.

When in doubt, confirm pad suitability with Kingspan or obtain written advice prior to installation.

General Requirements (All Kingspan Steel Tanks)

• The tank pad must be flat and level in all directions, with no more than 1° slope.
• The base must be capable of supporting the full weight of the tank when filled (1000L = 1000kg).
• Soft or uncompacted ground is not suitable.
• The tank may be installed directly on the pad — no geofabric or separation layer is required.
• The pad must support all edges of the tank base.
• Damage caused by pad erosion, subsidence, or incorrect preparation is not covered under warranty.

Tank Pad Type – What Is Suitable?

Kingspan tanks vary in suitability depending on tank style and size.

⚠️ Crusher dust pads are only suitable for larger diameter round tanks (2600mm and above).

If unsure of your tank size classification, confirm before construction.

Concrete Pad (⭐Recommended)

A concrete slab is the most suitable base for Kingspan steel tanks.

• Minimum 100mm thick concrete.
• Reinforced with F62 mesh (or higher grade if on sloping ground).
• Must be flat, smooth and level (≤1° slope).
• Should extend at least 100mm longer and wider than the tank.
• Allow minimum 5 days curing time before placing tank on slab.

Concrete Paver Pad

Paver pads must be installed correctly to avoid subsidence.

• Area must be cleared down to firm natural ground.
• Install a retaining border around the pad.
• Use a 75mm sand/cement mix beneath pavers.
• Base must be compacted thoroughly.
• Pad must support all edges of the tank.
• Tank may be placed immediately after installation.
• Do not fill tank above 2 corrugations for at least 48 hours.

Paver pads are not suitable for soft ground or garden beds.

Crusher Dust Pad (Large Round Tanks Only)

Crusher dust pads are suitable only for round tanks 2600mm diameter and above.

Requirements:

• Minimum 100mm thick crusher dust.
• Material must be fine grade (no large stones or sharp particles).
• Pad must be compacted, flat and level (≤1° slope).
• Retaining border required to prevent erosion.
• Pad must support all edges of the tank.
• After positioning the tank, exposed crusher dust should be covered with coarse aggregate to prevent erosion.
• Tank should be filled to at least 10% capacity immediately after placement to stabilise the base.

Crusher dust pads are not suitable for slimline, modline, square tanks, or smaller round tanks.

Tank Stands

If installing on a stand:

• Stand must be certified structurally adequate to support the tank when full.
• Stand must be level (≤1° slope).
• Platform must support all edges of the tank.
• Timber decking gaps should not exceed 25mm.
• Footings must be engineered and compliant with Australian Standards.

If supplying your own stand, consult a structural engineer.

Delivery & Compliance Notice

If at time of delivery the pad does not comply with Kingspan installation requirements:

• The tank may be returned to depot, and
• A redelivery fee may apply.

Installing a tank on a non-compliant pad may void warranty.

If you are installing a Stainless Steel Rainwater Tank, the base must be prepared correctly prior to delivery.

⚠️ Important: Failure to follow Stainless Steel Tanks Base Preparation Guide (PDF) may void warranty. Tank bases must be constructed before delivery.

If unsure whether your base is suitable, confirm in writing prior to installation.

General Requirements (All Stainless Steel Tanks)

• The tank must not be placed directly onto bare ground.
• The base must be firm, stable, compacted, flat and level.
• The base must be larger than the tank and fully support all edges of the tank.
• The base must safely support the tank when full (water weighs approximately 1kg per litre).
• The overflow must be piped at least 2 metres away from the tank to prevent undermining of the base.
• Tanks installed on an undersized or unstable base may void warranty.
• The base must be installed prior to delivery.

Base Size Requirements

Stainless Steel tank foundations must be constructed large enough to fully support all outer edges of the tank.

• There must be no overhang of the tank beyond the base.
• All outer edges of the tank must be fully supported.

Minimum Size Guidance

Manufacturer documentation specifies base extensions between 100mm and 150mm beyond tank edges, depending on tank type and base construction method.

To ensure compliance across all stainless steel tank models and base types, we recommend:

• Constructing the base a minimum of 150mm wider and longer than the tank.

This aligns with the most stringent published installation requirements and helps avoid delivery or warranty issues.

If unsure, confirm your base dimensions prior to construction.

Concrete Base (⭐Recommended)

A reinforced concrete slab is the most secure and maintenance-free option.

• Minimum 100mm thick reinforced concrete.
• Reinforced with F62 mesh (or higher grade if on sloping ground).
• Must be flat, smooth and level.
• Must extend at least 150mm beyond tank edges.
• Allow minimum 5 days curing time before delivery.

Concrete is the preferred foundation for long-term durability.

Concrete Paver Base

Paver bases must be constructed carefully to avoid movement over time.

• Area must be cleared down to firm earth.
• Lay a 75mm thick sand/cement mix beneath pavers.
• Base must be flat and level before placing pavers.
• Must follow the same size requirements as a concrete base (minimum 150mm wider and longer than tank).
• Tank may be placed immediately.
• Do not fill tank above the first 2 corrugations for at least 48 hours.

Paver bases are not suitable on soft or uncompacted ground.

Crusher Dust Base (Large Round Tanks Only)

Crusher dust bases are suitable only for large diameter round stainless steel tanks.

Requirements:

• Crusher dust must contain no particles larger than 5mm diameter.
• Minimum 150mm thick compacted base.
• Must be heavily compacted and level.
• A retaining border must be installed around all edges to prevent erosion.
• Base must extend 150mm beyond tank edges before border installation.
• Tank may be placed and filled immediately.
• Exposed crusher dust should be covered with coarse aggregate after placement to prevent erosion.

Crusher dust bases are not suitable for smaller or non-round tanks.

Tank Stands

If elevating your stainless steel tank:

• The stand must be certified structurally adequate.
• Surface must be flat, smooth and level.
• Gaps between timber boards must not exceed 20mm.
• Concrete footings must comply with Australian Standards.
• Stand must fully support all tank edges.

Do not use uneven supports such as untreated sleepers or corrugated iron decking.

Foundation & Corrosion Considerations

• If installing on a previously used base, ensure there is no contamination from incompatible metals.
• If placing a new tank where an old tank was removed, consider a protective membrane between tank and foundation to reduce corrosion risk.
• Avoid direct contact between stainless steel and dissimilar metals.
• Do not bury or backfill against the tank walls as soil can cause corrosion.

Warranty & Delivery Notice

• If the base is deemed non-compliant at time of delivery, delivery may be refused.
• Siting a tank on a non-compliant base may void warranty.
• Ongoing maintenance of the tank base is the customer’s responsibility.