Heavy-Duty Pond Underlayment, Precut Sizes & Rolls
Underlayment is the fabric layer that goes into the hole before the liner. It cushions the liner from rocks, roots and hard soil that would otherwise wear through it from below. Aquascape's Heavy-Duty Pond Underlayment is about 30% thicker than its Standard Underlayment, made for rocky, root-filled or uneven digs.
• About 30% Thicker: than Aquascape Standard Underlayment, for more protection on rough ground.
• Soft Polypropylene Geotextile: lets gases escape instead of trapping them under the liner.
• Non-Slip, Spreads Easily: stays put while you lay the liner over it.
• 11 Precut Sizes: boxed, from 5′ × 10′ to 15′ × 25′, to match common boxed liners.
• 15′ Wide Compact Rolls: 50′ and 100′ rolls folded to 46″ wide, so they fit in a pickup bed and unroll to the full 15′.
Aquascape Heavy-Duty Underlayment Sizes
| Size | Type | Shipping Weight | SKU |
| 5′ x 10′ | Precut, boxed | 8.05 lb | 42135 |
| 7.5′ x 7.5′ | Precut, boxed | 8.37 lb | 42136 |
| 8′ x 10′ | Precut, boxed | 9.59 lb | 42137 |
| 10′ x 10′ | Precut, boxed | 9.59 lb | 42138 |
| 10′ x 12′ | Precut, boxed | 11.63 lb | 42139 |
| 10′ x 15′ | Precut, boxed | 13.25 lb | 42140 |
| 10′ x 20′ | Precut, boxed | 15.75 lb | 42141 |
| 12′ x 15′ | Precut, boxed | 14.75 lb | 42142 |
| 15′ x 15′ | Precut, boxed | 17.7 lb | 42149 |
| 15′ x 20′ | Precut, boxed | 21 lb | 42143 |
| 15′ x 25′ | Precut, boxed | 24.75 lb | 42144 |
| 15′ x 50′ Compact Roll | Compact roll | 44 lb | 42147 |
| 15′ x 100′ Compact Roll | Compact roll | 82.25 lb | 42148 |
Compact rolls: 15′ × 50′ is a 15″ diameter roll and 15′ × 100′ is a 19″ diameter roll, both 46″ wide before unrolling.
What Size Pond Underlayment Do You Need?
Match your liner. Buy underlayment the same size as your liner so it covers the whole excavation, including shelves and the edges that tuck under rock or coping. Using our Aquascape 45 mil boxed liner? Pick the same precut size here. For larger liners from the 45 mil or 60 mil rolls, lay 15′ wide underlayment in strips side by side, overlapping the edges, until the hole is covered.
How to Lay Pond Underlayment
- Dig the pond and remove sharp rocks, roots and debris from the floor and walls.
- Unroll or unfold the underlayment into the hole and smooth it against the floor, shelves and walls.
- For more than one piece, overlap the edges so no soil shows between them.
- Lay the liner on top, then trim any excess underlayment at the edge once the liner is set.
Pond Underlayment FAQs
Do I really need underlayment?
It is the cheapest protection a liner can have. A rock or root pressing up from below can wear a hole through EPDM over time, and underlayment puts a cushion between them.
Does it work with any liner?
Yes. Underlayment is a separate fabric layer, so it goes under any EPDM pond liner.
Heavy-Duty or Standard?
This is Aquascape's Heavy-Duty grade, about 30% thicker than its Standard Underlayment. Choose it for rocky, rooty or uneven ground.
How wide do the rolls open?
Both compact rolls unroll to a full 15′ width. They are folded four times on the core so the roll itself is only 46″ wide.
Before You Order Pond Underlayment
- Order the same size as your liner, or enough rolls to cover the full excavation.
- Precut sizes ship boxed. Compact rolls are heavier (44 and 82.25 lb) but fit in a pickup bed.
- Shopping for liner too? See our EPDM pond liners.
- Keep a repair kit on hand for punctures after the pond is built.
- FREE Shipping via FEDEX, LTL Ground, & UPS. Ships in 2-3 Business Days.
- Ships Only to Lower 48 States of the United States
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