Sheets are produced as large as 40 feet in width. The use of a PVC liner prevents contaminants from entering groundwater sources or streams. In addition, it conserves potable water resources by preventing seepage loss. Narrower widths are also produced to offer applicators greater flexibility in positioning membrane.
Narrower sheets are also produced without factory seams (seamless) for use primarily in adhered and mechanically fastened applications. The major advantage of seamless material is the elimination of factory splice T-joints that occur when factory seams intersect with field splices. This reduction in T-joints significantly increases the potential for watertight performance by eliminating potential "water channels" into field splices.
The formula for sizing a pond liner is:
(Pond Length') + (2 x Pond Depth') + (2') = Liner Length'
(Pond Width') + (2 x Pond Depth') + (2') = Liner Width'
So... if you want a finished pond that is 12' long, 7' wide, and 3' deep; then using the formula above, the liner size you need is:
(12') + (2 x 3') + (2') = 20' Long
(7') + (2 x 3') + (2') = 15' Wide
This basic formula will work for ALL pond shapes.
The formula for determining the number of gallons of water in a pond is simple.
(Pond Length') + (2 x Pond Depth') + (2') = Liner Length'
For Square and Rectangular Ponds:
(Pond Length') x (Pond Width') x (Pond Depth') x 7.5 = Gallon Size
For example, if you want a finished pond that is rectangular in shape, and is 12' long, 7' wide, and 3' deep; then using the formula above, the gallon size of your pond is:
(12') x (7') x (3') x 7.485 = 1,890 Gallons
For Oval Ponds:
(Radius1') x (Radius2') x Pi(3.14) x (Average Depth') x (7.485) = Gallon Size
For example, if you want a finished pond that is oval in shape, and is 12' at the widest length accross, 7' at the shortist length accross, with a 3' average depth; then using the formula above, the gallon size of your pond is:
(6') x (3.5') x (3.14) x (3') x 7.485 = 1,480 Gallons
For fish ponds, a depth of at least 18", or deeper is recommended. Healthy fish LOVE to move up and down, as well as side to side!
For water gardens, the water feature should have a depth of at least 12", or deeper.
Check your local fence requirements (building codes) and freeze line depth.