Application
Box welded liners for raised ponds
Above-ground ponds demand a liner that fits the interior exactly — no excess material pushing against the walls, no creases at the corners.
Why choose a box welded liner for your raised pond?
No pressure on the walls from folded material
In a raised pond, excess liner material pushes against the walls from the inside. A box-welded liner lies flat — no stress, no bulging, no visible creases.
Precise internal fit
Raised ponds are built to exact dimensions. Your liner is manufactured to match — so it fits the interior perfectly without any adjustment on site.
Clean top edge finish
Box-welded liners fold neatly over the top of raised pond walls. The visible edge is tidy — especially important when the pond surround is a key part of the garden design.
Why raised ponds need a precise liner
An in-ground pond is forgiving — any excess liner material tucks under the soil at the edges. A raised pond is a different problem entirely. The walls are visible, the interior dimensions are fixed by the construction, and there is nowhere for surplus liner to go except against the walls themselves. A flat sheet liner in a raised pond creates a characteristic bulge — the material bunches at the corners and pushes outward against the sides. This is not just cosmetic: it creates pressure on the pond structure and, at the visible top edge, produces an untidy overhang that undermines the finished result.
A box-welded liner is cut to the exact internal dimensions of the raised structure. It drops straight in, lies flat against every surface, and folds cleanly over the top edge. For a raised pond that is part of a formal garden design, this precision matters.
Timber, steel and masonry raised ponds
Raised ponds are built from a range of materials — treated timber sleepers, Cor-Ten steel, rendered blockwork, brick, or galvanised steel tank sections. The liner requirements are consistent across all of these: it must fit the internal cavity precisely, must not exert lateral pressure on the walls, and must have a sufficient lip overhang for the chosen coping detail. We manufacture for all raised pond types. For steel and timber constructions in particular, the clean corner finish of a box-welded liner is a significant improvement over folded alternatives. See our measuring guide for guidance on how to take accurate internal dimensions.
Material options
The 0.75mm standard grade is suitable for most domestic raised ponds. The 1.0mm heavy-duty grade is recommended for larger raised features, commercial installations, or anywhere the liner may be subject to mechanical contact. Both EPDM and Butyl rubber are available and carry a 25-year guarantee. For a detailed comparison, see our material guide.
Shapes we manufacture
What to measure
For a raised pond, measure:
- Internal length (m)
- Internal width (m)
- Internal depth (m)
- Lip overhang required (m) — how far liner folds over the top edge
Frequently asked questions
Measure the internal length, width and depth of the raised pond structure. Add your desired lip overhang — the amount of liner that folds over the top edge. That is all we need.
Most raised ponds have vertical walls — if yours are slightly battered (angled), let us know when you enquire and we will factor this into the liner design.
For very small containers, a flat sheet liner is usually more practical. Box welding becomes most beneficial from around 500mm diameter upwards.
Ready to get a quote?
Send us your dimensions — we'll reply with a price and a technical drawing the same working day.