Hello all,

I'm busy with some research on the best way to enlarge my koi pond.

Once .... a very long time ago....

I came across an above ground liner pond that someone built d.i.y.

Does anyone here have experience in doing this? or
Does anyone have some url's that might be usefull in my search?

Thanks

Building Liner Ponds
by Brett Fogle



Surprisingly enough, it is usually in mid-summer that many gardeners begin to think about installing a small pond or water garden. Ponds don't need to be weeded or watered, and they can supply exuberant color in the form of water lilies and bog plants.


The sound of a splashing fountain or waterfall is more appealing than weeding a flower bed or mowing that section of lawn. Best of all, no matter how hot or wet it gets, the pond just keeps on blooming!



At this point you may start to think about the expense and labor of installing a concrete pond, and our 95 degree days are just about enough to stop this pond daydream in its tracks.



However, with the advent of newer pond liners and pre-formed pools, the misery associated with concrete mixing and finishing is a thing of the past. Heavy duty pool liners with 10 year guarantees are now common.


Preformed ponds in many different shapes and sizes are also an alternative method to create a quick pond at less cost than using concrete. Using these materials, the average gardener can install a decent size pond in less than one day, and have it stocked with plants, fish and fountain by the following morning.



The simplest kind of pond to build is an above-the-ground pond. Since no digging is required, it usually takes much longer to fill this pond with water than it does to build it!



There are many variations on this theme, but as an example, one can use treated lumber planks which are at least 2 inches thick by 12 inches wide, nail them together to form a rectangular shape of the desired dimensions, and place the form where the pond is desired.



This bottomless "box" can be placed directly on the grass, concrete, a deck, etc., and then the bottom is covered with some kind of padding or cushioning material. Most books say to use sand, but I think the perfect material is roofing felt. It is cheap, convenient, lies flat, makes a barrier to weeds, and provides a good cushion for the pool liner.



Once the roofing felt is in place, the pool liner can be dropped into the form and you begin filling the pond with water. A few staples on the outside of the pond form may be needed to keep the liner from blowing into the pond, but be sure to use just a few, and place them at the edge of the liner.



As the pond fills, the weight of the water will do a good job in smoothing out wrinkles, but if you are a perfectionist, you can help smooth them out by hand before there is more than one inch of water in the bottom of the pond. While the pond is beginning to fill, you can check the level of the form, and if it needs to be raised a little on one or two sides, this can be done by carefully inserting some shims to raise the forms where needed.



If you prefer the pond to overflow on a certain side (like, into the flower bed, rather than onto the deck!) then you may want to leave the overflow side a quarter inch lower than the rest of the pond.



You should wait until the pond is completely filled before cutting any excess liner or doing any permanent stapling. This will give the water pressure enough time to pull the liner into every nook and cranny where it needs to go; some of those few holding staples which you used to hold the liner in place may actually tear loose as the pond fills, but if you stapled the liner on the outside of the form, near the edges, then no harm is done... you will be trimming some of that excess liner off, anyway.



It really does take longer to fill this kind of pond than it does to build it. I once built a twenty-by-thirty foot pond in two hours but it took all night for it to fill with water.



I think an ideal depth for an above ground pond is about 14 inches, but it can be deeper or more shallow than that, depending on what materials you are using for the form. Railroad ties, landscape timbers, concrete blocks, etc. are all possible materials for pond building.



Remember that any kind of wood must be pressure treated if you want it to last more than a year! Although I mentioned rectangular shape, if you have some carpentry skills, you can also do triangles, pentagons, ponds within ponds, etc.



Ponds built with treated lumber planks do not need any side support if they are less than 8 feet or 10 feet long; if you are building larger than that, you will want to drive a stake into the ground where the planks are to be nailed together, so the water pressure won't make the planks bow outward. So, if you know how to use twelve nails to nail four planks together, then you can build a pond. If you are feeling lazy, have the lumber yard cut the planks to size you need. Borrow your neighbor's staple gun, find those scissors buried in the kitchen drawer, and you are in business!



Pond liners can also be used to make an in the ground pond. The advantage is that you can make any shape pond you want, and the ground itself supports the sides of the liner.



It is a good idea to use a flexible garden hose to lay out the pool shape you want. Once everyone agrees that it is a pleasant shape, and it is large enough, you can dig a trench along side the hose, and start digging.



Remember, the pool does not have to be more than 12 to 16 inches deep, so don't get carried away. If you want a waterfall, some of the excavated soil can be mounded up near the pond for later waterfall construction. In some cases, it may be useful to use some of the soil for a berm around the pond, so that is another way to dispose of excavated soil.



Once the pond is excavated, check the level, decide which side you want excess rainfall to flow from, and then you are ready to line the hole with roofing felt, running it across the pond, up the sides onto the edges of the pond. Drop the liner in, weigh it down lightly with some rocks around the edges, and start filling.



Again, do not trim any excess liner until the pond is completely filled. Some pond books say you should create a shallow shelf in the pond before putting in the liner, but they don't have our river sand and rainfall to deal with. I think it is better to build the pond to a depth of 14-16 inches, and just use bricks to prop up those bog plants that don't want to sit too deep in water. This gives greater flexibility in rearranging the pond plants as you wish, and avoids the calamity of a shelf suddenly slumping into the pool. When using pool liners, whether in the ground or above the ground, it is important to conceal the edges from sunlight, since that is what eventually breaks down most liners.



Using stones or lumber planks to finish off the edge of your pond will make it more appealing, and enable the liner to live up to its ten year guarantee. Even the heavier, preformed plastic ponds should have their edges covered by sod or some paving material, so the sun can't reach it. Some final pointers: if possible, locate your pond away from trees, in a place that gets at least five hours of direct sun daily. This will allow you to grow a wide variety of pond plants.

Thanks Paul

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It can be done

Hi,

I agree with the posting on pond liners with one exception - the depth.

If you are going to build a pond decide - early on - if you are going to use it as a water feature or a koi pond.

As a water feature the advice given is great. But do not be tempted to add koi later. Gold fish are OK in these features. As a koi pond a re-think is needed on the depth for a start.

You can do wonders with a plastic liner. I am not sure why they are not promoted more in South Africa.

Also every waterfall or stream should have a backing of a plastic liner. The hairline cracks that plague pond owners are not a worry with liners.

Try to get liners that have UV protection against the sun. Th eblue liners uses in kiddies swimmin gpools will preish rapidly and start to crack.

Use a 1000 micron liner (1mm). The 250 or 500 micron liners are too thin. Although you can get away with the 500 micron - if you do not have dogs that enjoy water.

I have had the UV protected liners in koi ponds since I started with Koi in 1972.

In England there are an estimated 2.2 million ponds. Over half of those are plastic liners.

Regards,
Chris

Good Day everybody,
I manufacture linings and movable dams for the various sectors in the market. I make a range of P.V.C tanks up to 10 000L that is supported in a PVC pipe frame that is ideal for breeders and hospital tanks.

On the pond liner side, you have three options.LDPE plastic liners, these plastic liners only drawback is on complex shapes they show wrinkles and welding on tight corners tends to crack. They work fine in bigger applications like ground dams. A 500 to 1000 micron LDPE plastic liner needs to be manufactured on site; pre making and folding of the liners tend to make cracks. The 1000 micron liner is impossible to fold due to its thickness.
Both the 500 and 1000 micron offers the same UV protection the only difference would be the 1000 micron can withstand more mechanical damage.

Secondly is your food grade Vinyl, we use a 500 gram Vinyl for our pond liners, which is allot thicker than your Pick & Pay Porta pools that is only about 300 grams.
The nice thing about vinyl is that it does not contain a reinforcing base fabric, and that allows it to stretch. Making it possible to have it custom made to the design of your pond, be it above ground or any application. You can build a fancy design out of bricks and a Vinyl liner will do the job of keeping your water in at a fraction of the cost. Because the Vinyl fits so nicely without any creases you would not even notice the liner.

Thirdly is reinforced P.V.C in 550 gram, 700 or 800 grams. Works the same as the vinyl, the difference being the reinforcing makes it allot stronger than the other materials mentioned. Although it still stays flexible just like the Vinyl, the only difference it does not stretch, so measurements for a fancy structure needs to be exact to avoid wrinkles. It can take allot of mechanical damage, when you get a hole in it it will not tear any further due to the reinforcing.

Both P.V.C and Vinyl liners get joined by Hi Frequency welders in the factory, the welding process gives a water tight join that will not come apart like glues. Flat sheets can be made up to order and folded in to a small block of up to a 1000 sqm.Customs shapes can be made up from detailed drawings as well.

All of the above materials contain UV block in them. The sun is the biggest enemy of any type of material; I have P.V.C linings in cement dams in the Northern Cape that has been standing in the sun now for 8 years without any damage. The parts of the lining that is under the water will not be greatly affected by the sun as seen on these cement dams,given that the cemet dams are much deeper, than the ponds. There is ways to hide the top half of your lining from the sun, giving you maximum life out of your pond lining.

I did my first pond with scaffolding planks (228 mm 38 mm) above ground, (3m x 2m x 1m) but the pressure of the water soon bend the planks and it started to rot. Sleepers are an option but very expensive.

I believe the best is to do an above ground liner pond with angle iron and waterboard inside, nicely varnished on the outside.

The one on Joeskoi's website will not last.

I used the 250 micron DPC building liner from Gundell and it worked quite fine. Is it really neccesary to use the much more expensive 700?

Did you use support beams on the structure before closing up with the scaffolding planks? We manufacture Abalone tanks for the abalone farms (see attached pic) the sizes are more or less the same as the scaffold pond that you build, and some bigger. The frames are wooden beams with the PVC visible, some of the first farms in Hermanus linings are 10 years old and going strong so are the frames. If your base frame is correct you can use hardboard to cover your frame. Our portable PVC tanks up to 10 000 litres are only supported in a 50mm PVC pipe frame.
250 Micron building plastic will not support the water in such a frame, they tear quickly, repairs is a night mare.LDPE works fine when working with flat sheets. My personal feeling when spending money on a Koi pond, I want it as a feature in my garden, and it must not look as if I used a liner. With LDPE plastic laying a flat sheet into an L or rectangular shaped pond, you will end up with creases and folded corners.
You can join LDPE with a heat process. To fit a custom shape, like on a 90 degree corner we use an extrusion welder (heat gun that feeds a plastic rod normally used for pipe fittings in ground dams) a 250 micron liner is to thin you burn holes in the plastic. On the 500 micron it is touch and go with an extrusion welder, and a 1000 micron LDPE plastic is so hard it will not conform to curve and bends.1000 micron LDPE are used in industrial applications like landfills. Price wise more expensive than Vinyl and PVC.Using 500 micron on a custom shape pond will cost you more than PVC and vinyl unless using flat sheets, due to the fact that the joining process is more expensive, because it can’t be premade on custom shapes, corners are more involved and risky than with PVC and vinyl that is flexible and joined by High Frequency welders, and they look natural.

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