Pool Liners for Garden Ponds: Design, Marking Out & Profiles

Designing & Marking Out a Lined Garden Pond

Pool Liners: Flexibility & Planning

Liners offer maximum flexibility but mistakes at marking-out stage have long-term consequences. Define excavation area carefully before buying liner to ensure adequate fit without compromising shortcuts.

Defining the Pool

Lay out approximate shape on ground, adjust until pleasing. Even formal pools need this for proportions. Use pegs/string for formal, rope for informal (hosepipe often uncooperative). For informal pools: curves/arcs no tighter than a lawnmower can negotiate → liner fits snugly. Essential if grass to water's edge. View from all angles, especially house (including upper floors). Leave line/rope for 2–3 days, adjust as needed.

Marking Out the Pool

Start from fixed point. If scaled plan exists, use path/building as baseline. If by eye, choose base point, drive stake. Circular pool: Centre from baseline, stake, string = radius, pointed stick on end, walk around marking (sand/lime). Oval pool: Centre + end canes, stakes at 2/3 distance from centre, loop string around stake and far end cane, remove other end cane, pull first, scribe oval. Rectangular pool: Baseline = side length, parallel to features. Right angles via 3-4-5 method: 3 units on baseline, 4-unit string arc from first cane, 5-unit from second, intersection = right angle. Repeat for all corners. Irregular pools: Sweeping arcs preferred over fussy niches (crumple liner). Use formal principles on embracing rectangle.

Marking Out the Pool Profile

• Circular: Centre peg, string = radius, sharp stick, inscribe circle.
• Oval: Fixed point for centre/ends, loop string around far peg, use centre cane, tighten, mark oval.
• Rectangular: Baseline 3 measures, strings 4 & 5 measures, cross arcs for right angle.