AboveGround Water Tanks

Most above ground tanks are manufactured from either polyethylene (MDPE) or fibreglass (GRP). Polyethylene tanks are lightweight, cost-effective and resistant to corrosion, making them ideal for smaller domestic installations. GRP tanks offer greater structural strength and are often specified for larger capacities or where a sectional build is needed on site.

In most domestic gardens, an above ground water tank falls under permitted development and won't need planning permission, though this can vary depending on tank height, position and whether your property is listed or in a conservation area. It's always worth checking with your local planning authority before installation, particularly for larger commercial-scale tanks. Building regulations may also apply if the tank forms part of a fire suppression or potable water supply system.

Above ground tanks need a firm, flat, level base capable of supporting the full weight of the tank when filled with water — this is typically a concrete slab or well-compacted hardcore and sand. The base must extend beyond the tank's footprint to provide even support across the entire underside. Uneven or unstable ground can cause stress cracking or distortion over time, so it's not a step to skip.

Yes, provided the tank is WRAS-approved and constructed from materials suitable for potable water contact. Tanks-Direct stock dedicated potable-grade tanks that are UV-stabilised and light-excluding to prevent bacterial or algal growth inside. If in doubt, check the tank's specification sheet to confirm potable approval before connecting it to a drinking water supply.

Because above ground tanks are exposed to the elements, insulation jackets or tank housings are recommended in colder regions to prevent freezing, particularly for tanks feeding a livestock or irrigation supply. Pipework should be lagged and, where possible, buried below the frost line as it enters or leaves the tank. Some tank ranges also offer insulated or twin-wall options for added protection.

Tank sizing depends on intended use — a small domestic rainwater harvesting setup might only need a few hundred litres, whereas agricultural or fire suppression use can require tens of thousands of litres. Consider daily demand, mains backup requirements, and available space alongside the tank's footprint and access route before ordering. Our team can help you work through capacity calculations if you're unsure which size suits your application.