How to install a Geotextile protective underlay liner

Geotextile protective underlay is a tough, permeable material that is used to separate, reinforce and protect the primary pond liner from being punctured by rocks or other sharp objects. Geotextile is made from high quality mechanically bonded polyproplene and available in different grades of thickness for different application types. Geotextile, as sold by Liners Online is needle punched in the manufacturing process to add ‘air’ to the fabric to give it highly effective cushioning properties.

A lot of effort (and money!) goes into building a pond so it is worth the extra spend installing a pond liner protective underlay. The integrity of a pond liner is compromised when installed directly onto the ground because the force exerted by the weight of the water onto the pond liner will push it down onto any rough points in the ground creating straining points that may puncture over time. Water weighs one tonne per square meter, so that is a lot of force pushing down on the pond liner of an average size pond. Installing geotextile protective underlay

Geotextile underlay also acts as an escape route for any gasses that may build up under a pond liner. For garden pond designs that include the placement of soil, gravel, rocks or concrete features above the pond liner, then it is highly recommended to install Geotextile both above and below the pond liner for added protection.

Geotextile protective underlay installation

  • Dig the hole for your pond to the desired size and shape. Use a  spirit level to ensure the ground around the periphery of your pond dug-out is level.
  • Prepare the top most layer of soil by removing as many stones, rocks and roots as possible. Use a granular fill if you find any weak soil pockets. Smooth the ground as much as possible.
  • Take accurate measurements of your pond to order the exact size Geotextile protective underlay.
  • For large ponds wider than the role of underlay, ensure a sufficient overlap (by 12 to 18 inches) so that any ground movement won’t expose the pond liner to any rough, stony ground risking a puncture. 
  • For garden pond builds it is important to lay a protective underlay first. Geotextile is permeable and has the ability to reinforce and protect all types of pond liner.
  • When laying over the ground, secure it is place using ground pegs or boulders so it doesn’t slide out of place when installing the pond liner.

Why install a protective overlay liner?

There are a few situations where protective underlay liner is used on top of the pond liner such as around the edge of a pond before the stones or slabs, that will form the border of the pond, are put in place. Similarly, if your pond features an underwater shelf or platform for shallow water plants, those areas too should use a protective overlay. The presence of an overlay can also provide some protection against the sharp claws of pet dogs or cats – and even the stab of a heron’s beak!

Another area that can benefit from a protective pond liner overlay is underneath objects such as stone features or plant containers that you add to your pond. Or, when creating an attractive pebbled pond floor. As well as protecting the pond liner, the textured surface of the fabric will discourage pebbles and other features sliding about.

You might find our previous Blog article ‘How to get your pond liner size just right’ helpful in calculating the right size for your pond liner and underlay to avoid over or under ordering.

 

Planning a pond but not sure which pond liner to buy

Pond liner use is two fold, namely to retain the water in your pond and to maintain water quality. The choice available to pond builders is either a preformed pond liner, flexible flat sheet liner or to line with concrete (the latter of which is seldom used today due to cost, maintenance and durability). Flexible pond liners include PVC or a rubber pond liner of which the options include Butyl or Epalyn (also called by it’s generic name – EPDM rubber liner). Flexible, flat sheet pond liners offer the best choice in pond design and the ability to create a more natural looking pond build.

Pond liner advise as given by the experts

  • buy the best pond liner you can,
  • don’t buy a pond liner in isolation but also give serious thought to the protective underlay
  • don’t buy your pond liner and underlay until the exact dimensions of your excavation are known (to avoid wastage or disappointment!)
  • allow enough pond liner for an overlap around the edges to secure in place by using appropriate materials such as boulders or paving bricks.

Best quality liners are Butyl and Epalyn rubber liners. There is no financial compromise with these genuinely high quality products. Butyl is the most well known pond-lining product in the UK although Epalyn (EPDM rubber liner) is surpassing it’s popularity die to the price differential. Both types of rubber liners are hardy and have great qualities such as flexibility and elasticity. They are unaffected by all weather conditions and temperatures. They are also much more heavy duty versus PVC and are less likely to be damage. So, now to decided between Butyl and Epalyn? Both are high quality, but Epalyn has a higher specification, is slightly more flexible, has the same guarantee and is considerably more cost effective. So if cost is the deciding factor, then Epalyn would be my choice of pond liner. But, lets look at each in more detail.

PVC pond liner for ornamental ponds

The most common type of garden pond liner is made from PVC (Polyvinyl Chloride), supplied as standard 0.5mm thickness. This type of pond liner is ideally suited for smaller, ornamental type pond designs. It is robust enough to last for at least 10 years provided it is installed above a protective underlay liner. PVC is flexible so it will readily follow the contours of your pond. However, it does need to be fitted correctly as it doesn’t stretch readily so will damage if you try to fit into narrow gaps and crevices. PVC pond liner

PVC has limited UV resistance so it will turn ‘brittle’ if exposed to too much sunlight, causing it to crack. PVC also does not repair well, going brittle when a repair treatment is applied.

The key benefit of a PVC liner is the price, being the cheapest option on the market, so if you have a tight budget, then PVC will suit your needs, especially if the pond is small. If you are keen to turn your build to a hobby and are aiming at a designer pond to house Koi fish, then it is worth investing in a superior quality liner. It will last longer, and if needed will repair with far greater success. Sharp objects in the ground, such as stones, can pierce a PVC pond liner much easier than a Butyl or Epalyn. 

Butyl pond liner for larger pond builds

Butyl is a synthetic rubber membrane with excellent properties that make it far superior to the standard PVC pond liner. Butyl can be used for more demanding applications such as the lining of ponds and lakes. Butyl is more costly and this is due to the rising cost of the rubber polymer that creates Butyl. This rubber liner offers superior stretch qualities and is highly puncture resistant. Butyl pond liners have for a long time been the ultimate choice, however with the more recent availability of a cheaper, equally high quality alternative, Epalyn has now ‘knocked’ Butyl off it’s pedastal.

Butyl generally comes with a guarantee from 25 years to a lifetime when installed above a protective underlay. Butyl and Epalyn have a matt finish, which is a great advantage for pond keepers not wanting a shiny ‘new looking’ liner as with PVC. 

Epalyn liners for a superior build  

Both Epalyn (EPDM = ethylene propylene diene monomer) and Butyl pond liners are a synthetic rubber membrane with exceptional physical properties with a similar look and feel to them. Epalyn is flexible and resistant to UV, sunlight and a wide range in temperature extremes. It is tear resistant and unlikely to crack when installed with a protective underlay.  

If you are serious about your pond and want a liner that offers lifetime protection, then Epalyn is an excellent choice.  It is non-toxic to fish, offers far superior qualities versus PVC liners and offers a vast range in pond design flexibility.  If we were to recommend a pond liner for your pond build, it would be a Epalyn 0.75mm or 0.85mm – or 1mm for large ponds or lakes.  It is black in colour and can be recycled, which is a good feature for those that prefer environmentally-friendly choices.

We hope that we have offered you sufficient advice and information about the choice of available pond liners, be it a PVC liner, Butyl or Epalyn rubber pond liner.  

Epalyn pond liners

Butyl pond liners 

PVC liner 

Tailored-to-fit or Box-welded pond liners 

 

Calculating the water capacity of a rectangular or square shaped pond

Ponds are the perfect addition to any size garden. A water feature soon becomes a magnet to wildlife attracting them into your garden in a way that makes you feel very honoured to have their presence.  Ponds bring a sense of relaxation and reward. One aspect to maintaining a healthy environment is ensuring you don’t over-stock with fish. So here are simple formula to calculating pond water capacity.

There are many things to consider when planning a garden pond build, such as where the pond is to be sited, budget for the project, materials required and whether it should be a wildlife or fish pond. As part of the construction process you will need to measure the dimensions of the hole dug for your garden pond to calculate how much pond liner and protective pond underlay to order to minimise waste. Following these steps, you will also want to know the volume of your pond to then be able to shop for the correct size pond pump and filter. Continue reading

Discovering Newts in your Garden Pond

Many children have a great fascination towards small creatures found in gardens, fields or ponds such as earthworms, frogs, tadpoles and newts. As a result of my daughters interest in pond wildlife, I find myself constantly on the look out for ponds noting the various species of aquatic plants, the type of edging added to protect the pond liner and whether there are fish present. Continue reading

Repairing a PVC pond liner

PVC pond liner repair is possible although there is the risk of it becoming brittle. Some pond liner repair kits are designed for use on rubber pond liners only so read the label first.

Pond liners if installed correctly and placed above a protective underlay liner, are less likely to puncture. However, a PVC pond liner doesn’t have the same UV resistant qualities as Butyl and Epalyn (EPDM) pond liner therefore over time there is a risk of the pond liner becoming britle and, as a result become more vulnerable to puncturing. The claws or sharp beaks of visiting wildlife can also be the perpetrator of a damaged pond liner. A drop in water level through evaporation will expose a pond liner to higher levels of UV radiation, weakening the pond liner and again heightening the risk of puncturing and the resulting drop in pond water level.

A PVC pond liner doesn’t repair as well as a rubber pond liner such as that of Butyl or Epalyn (EPDM), so depending on how big the puncture is, you will need to weigh up whether to try and repair the leak or just replace your pond liner given that PVC have a life span of around 10 to 15 years.

Finding the puncture to your PVC pond liner? 

If the water level of your pond drops at a faster rate than expected from evaporation alone then the next step is to find the cause. This may mean draining the water out, but only to the point where the puncture becomes visible. Use a garden hose to drain out the water.

For ponds that are home to fish, they will need to be removed and put in a temporary holding tank or plastic bath before draining your pond. Fill the tank with water from your pond first to reduce stress and risk to the health of your fish.

  • If the leak is at the bottom of your pond, then repairs will be more of a challenge but not an impossible one. 
  • Clean a wide area around the puncturea of algae, grit and any plant life using a clean rag.
  • Rinse the area and dry it thoroughly (you can use a hair dryer to make sure that the surface is thoroughly dry) before roughing up the damaged surface with a wire brush. A rougher surface is more porous and holds the glue more effectively.  
  • Mark the punctured pond liner by circling it with a piece of chalk.
  • Cut a piece of PVC liner in a circular shape. The shape will need to be larger than the size of the hole.
  • Spread PVC liner patching glue or waterproof sealant over the surface of the tear and the surface of the patch. Allow the glue to dry until it is no longer tacky to the touch. Press the patch, glue side down, over the hole in the pond liner so that the two glued sides are sandwiched together. Apply the patch uniformly over the hole to prevent wrinkles. Hold for 30 seconds. 
  • Wait 48 hours for the glue to cure before refilling your pond and re-introducing your fish back into your pond.

Pond liner repair kits such as the traditional Mastic Tape are not suitable for repairs to PVC pond liner

Where can I buy a high quality pond liner?

Knowing which pond liner is considered to be a high quality pond liner, how much to order and where to buy are questions many aspiring garden pond owners want an answer to. It is also about the financial outlay and getting the best value for your spend.

A high quality pond liner will play a vital role in the containment of water particularly for those built on porous ground. A pond liner manufactured from synthetic rubber material is considered high quality. Should they tear or get punctured, they can be repaired without too much disruption to the pond. Although, this will depend where in the pond the leak occurs and therefore where the liner is punctured. Synthetic rubber pond liners, Butyl and Epalyn (also know as EPDM) are available to order from a number of pond supply websites and garden centres. Pond liners can be purchased according to your own set of dimensions or you can select from pre-cut pond liner kits.

Which high quality pond liner to order?

Butyl and Epalyn rubber pond liners (EPDM) are considered to be the best on the market based on the following features:

  • Display excellent properties of both durability and flexibility which means they can be readily manipulated into various pond shapes and sizes
  • They are better for cool climates and have superior UV resistance
  • High expansion and contraction characteristics that enable it to conform to objects below the pond
  • Should earth movement occur, such as settling, Epalyn high elongation properties will enable it to stretch
  • Very stable in extreme temperatures and other environmental conditions
  • Easy to repair either of these materials (although damage is minimal when installed above a protective underlay)
  • Epalyn and Butyl feel and perform in a very similar way
  • Non-toxic to fish and other pond inhabitants
  • Kind to the environment as they don’t leach chemicals into the ground

The technical difference, however between Epalyn and Butyl is the polymer. To be called Butyl the sheet must contain more than 50% butyl polymer. The polymer is the ingredient that makes the sheet elastic. In most pond grade Butyl there is usually a percentage of EPDM polymer mixed in. Epalyn, however is made with 100% EPDM polymer. EPDM polymer is more readily used around the world in a range of industries as well as for lining ponds and it is generally cheaper.

rubber pond liner installation

If you are planning to build an ornamental pond whether to house KOI fish or for a display of water lilies then a box-welded pond liner is best suited to this design. Box-welded or tailored-to-fit liners are most frequently fabricated from Epalyn rubber liner material. The main advantage of this type of liner is that it fits perfectly into a vertically-sided formal pond design without any creases or folds thereby creating a neat finish.

For Koi enthusiasts wanting to build an formal shaped Koi pond, Liners Online pond liner supplier will need the exact dimensions of your pond to fabricate a box-welded pond liner for a snug fit.

For all other creative pond designs we supply flat sheet pond liners and have a pond liner size calculator on our website to help customers with measurements.

Liners Online have more than thirty years experience in the water containment and waterproofing industry so can offer support and expert advice on garden pond construction as well as pond liner installation.  

High quality pond liner installed in various pond projects

 

How to Calculate Pond Liner Dimensions

Pond liner dimensions are critical to the perfect finish of your pond build. In this article we offer advice on how to take accurate measurements of your pond and use them to calculate the amount of pond liner and protective underlay you will need to order.

The use of pond liners in pond construction offers greater flexibility in pond design versus using other materials to line and retain the water. One factor to consider when you go creative with a pond design is to ensure you use the correct dimensions to calculate the exact amount of pond liner and underlay to order to complete the job properly with minimal wastage plus ensuring enough to add an overlap – visit ‘Pond planning and construction‘ for more information’ Continue reading

Rubber pond liners offer design flexibilty vs preformed ponds

The use of a flexible pond liner offers design flexibility. They allow you to create a pond that works well with your surrounding garden landscape. A preformed fibreglass mould allows you to create a garden pond just as easily but are generally a more expensive way to achieve a stunning water feature in your garden. The real benefit of a pond liner is that you can expand the size of your pond at a later date if you so choose or you can add features such as a waterfall or bottom drain.

Want to build a wildlife pond in your garden with a beached are and planting shelves? All that can be achieved with a rubber pond liner. The design flexibility offered means that you can create easy access for wildlife. Your pond liner is also likely to last more than 25 years.

Flat sheet pond liners offers the flexibility to build a pond that suits your requirements. Types to choose from include Epalyn (EPDM rubber), Butyl and PVC. Overall, pond liners made of rubber are recommended, as they are more durable, resistant to extreme weather conditions and easy to work with. PVC pond liner being installed in a garden pond dug-out

Butyl pond liners can withstand the severity of both frost and UV radiation. Although thicker than the PVC pond liners, Butyl is still remarkably flexible and easy to use. Butyl is ideal for larger installations due to its much tougher qualities.

Epalyn pond liners are also more rugged than PVC liners. They are better for cool climates and offers UV resistance and has high expansion as well as contraction characteristics. Epalyn can be obtained in various”grades” (thicknesses).

Unlike preformed ponds, rubber pond liners can be easily shaped to fit the contours of the pond shape, allowing for a more unique design. Once a rubber pond liner has been installed correctly, it will require little or no regular maintenance. A flat sheet rubber pond liner offers great design flexibility

For a lined pond, it is also wise to invest in a protective underlay, which acts as cushioning material between the pond liner and the surface of your pond excavation. Before buying your pond liner and and underlay make sure you know the exact pond liner size required.

When building a pond it really is all down to choice and wether you want a more natural looking pond build that you are likely to take on as a growing hobby.

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All garden ponds require regular, simple maintenance to keep it looking good as well as to attract the wildlife that develop a working ecosystem. Deep ponds do tend to remain cleaner than shallow ones. Algae, particularly blanket weed tends to occur in newer ponds where a balanced ecosystem Continue reading

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Tips on restoring a neglected garden pond

Restoring a neglected garden pond may seem a massive task. But, before you consider that the only solution is to drain and completely clean out your pond (unless you know that your pond liner is damaged and requires repair), pause for a moment as what can seem overgrown and dying may be a valuable wildlife sanctuary. Ponds with a thick cover of plants are often richer wildlife habitats than open waters. Having said this you may want to rather take the following more sensitive steps in your ponds restoration. Continue reading