This underlayment is a heavy (7 oz to the yard) synthetic matting. Our Pond Liner Underlayment comes in 5 x 15 ft roll (75 sq. ft.). It should be placed under the pond liner, when a pond is being installed. Pond Underlayment is a geotextile material used to protect the liner from roots and rocks.
Enter the number of rolls that you wish to purchase in the quantity box then click the 'Add to Cart' button.
The table below shows the amount of underlayment needed for the liners we offer.
| Liner Size | Rolls & Size of Underlayment |
| 8 x 10 | 1 roll of 5 x 15 |
| 10 x 10 | 1 roll of 10 x 15 |
| 10 x 15 | 1 roll of 10 x 15 |
| 15 x 15 | 1 roll of 15 x 15 |
| 15 x 20 | 1 roll of 5 x 15 & 1 roll of 15 x 15 |
| 15 x 25 | 1 roll of 10 x 15 & 1 roll 15 x 15 |
| 20 x 20 | 2 rolls of 15 x 15 |
| 20 x 25 | 2 rolls of 10 x 15 & 1 roll of 15 x 15 |
| 20 x 30 | 1 roll of 10 x 15 & 2 rolls of 15 x 15 |
| 25 x 25 | 3 rolls of 15 x 15 |
| 25 x 30 | 1 roll of 5 x 15 & 3 rolls of 15 x 15 |
| 30 x 30 | 4 rolls of 15 x 15 |
| 5 x 50 | 1 roll of 5 x 15 & 1 roll of 15 x 15 |
| 5 x 100 | 1 roll of 5 x 15 & 2 rolls of 15 x 15 |
| 10 x 50 | 1 roll of 5 x 15 & 2 rolls of 15 x 15 |
| 10 x 100 | 1 roll of 10 x 15 & 4 rolls of 15 x 15 |
| 15 x 50 | 1 roll of 5 x 15 & 3 rolls of 15 x 15 |
| 15 x 100 | 1 roll of 10 x 15 & 6 rolls of 15 x 15 |
| 20 x 50 | 1 roll of 10 x 15 & 4 rolls of 15 x 15 |
| 20 x 100 | 9 rolls of 15 x 15 |
| 25 x 50 | 1 roll of 10 x 15 & 5 rolls of 15 x 15 |
| 25 x 100 | 1 roll of 5 x 15 & 11 rolls of 15 x 15 |
| 30 x 50 | 1 roll of 10 x 15 & 6 rolls of 15 x 15 |
| 30 x 100 | 1 roll of 5 x 15 & 13 rolls of 15 x 15 |
| 35 x 50 | 8 rolls of 15 x 15 |
| 35 x 100 | 1 roll of 10 x 15 & 15 rolls of 15 x 15 |
| 40 x 50 | 9 rolls of 15 x 15 |
| 40 x 100 | 18 rolls of 15 x 15 |
| 50 x 50 | 1 roll of 5 x 15 & 11 rolls of 15 x 15 |
| 50 x 100 | 1 roll of 5 x 15 & 22 rolls of 15 x 15 |
