Pond Liners and Underlay

Do I need a pond liner? What kind of liners are there? What sort of underlay would be best? Here, you can view all of the liner characteristics, guarantees and tips.

Ponds can be constructed from a number of materials and some of these do not require the basis of a pond liner to allow them to be watertight; but in the majority of cases a liner is required.

Concrete constructions can be painted with a sealant such as G4 which creates a waterproof bonded layer and therefore withdraws the need for a pond liner. G4 sealant is available to purchase at Pondkeeper. 

The length, width and depth of the pond is required for this, the measurements need to be at the largest point for each.  You can use our Pond Liner Calculator to calculate the liner size that you would need.

Below, you can see all of the different liners and underlay that we sell alongside their various characteristics.

Non-Rubber Liners

Flexiliner

• L.D.P.E (low density polyethylene)
• Its lightweight which means its easier to manoeuvre into position and shape
• Its stronger; a 3-ply woven which means its harder to tear.
• 0.35mm thick
• Durable and laminated on both sides with a rot/UV resistant coating
• Our best selling liner 

PVC liner

• Think of this liner as a halfway house between Flexiliner and rubber
• 0.5mm thick
• 15yr and 30yr Guarantees
• Not reinforced and tear proof like Flexiliner but a thicker, denser fabric with greater elasticity

Rubber Liners

Butyl Pond Liner

• 0.75mm thick
• Natural Rubber
• More traditional made method
• Its is a hardy liner and has great qualities such as flexibility and elasticity
• UV stable and therefore copes with longer periods in the sun
• Widely accepted as one of the best, most flexible and hardy pond-liners on the market
• Non toxic to wildlife and plant-life 

• E.P.D.M (Ethylene, Propylene, Diene, Monomer)
• 0.75mm thick
• Synthetic Rubber
• Its Modern Manufactured
• It’s a rubber based material which means its stretchy
• Not affected by UV light, temperature or age
• Colour of material – Black
• Does not shrink, lose weight or become brittle
• Animal and plant friendly

Pond Underlay

Basic Underlay

How do I repair my liner?

Flexi Liner  / Rubber Repairs

These are the most common type of liner that we sell and therefore the most likely type that will need repairing.  These liners although very different in material are both repaired in the same way using Cold Glue tape and a patch of the same liner.  The area around the hole needs to be dry and clean having had any dirt scrubbed off.  This will ensure that the glue sticks well to the liner.  The basic way of repairing a hole is to put a piece of the cold glue tape over the hole, cut a patch slightly bigger than the area around the hole, lay the cold glue tape around in a square matching the size of the liner patch.  Place the patch on top and push down firmly, ensuring that a water tight seal is made all the way round.  Leave this to set for a few hours and it should then be good for filling back up.  Please note the pond does not need to be emptied, it only needs to be drained so that the hole is exposed out of the water.

PVC Repairs

PVC Liner is quite a fiddly repair and must be done with specific PVC repair kits.  This is due to the shinny nature of the product and that the wrong glue can damage the liner.  These kits work in a very similar way to the normal liner repair kits, but the glue tends to come in a squeezy tube and is applied to the back side of the patch and then stuck down.

Fibre Glass / Concrete Pond Repairs

Fibre Glass repair kits involve rubbing the pre formed pond down with sand paper to provide a rough surface to stick too, mixing two chemicals together to make a glue, placing a sheet of fibre glass over the whole and painting the glue over the top to set and fix in place.

Concrete Pond repairs use a special putty to fill the crack or gap in the wall, or alternatively you can simply re-render the crack to fill it in and paint with G4 pond sealant. (Please NOTE: G4 Concrete sealant cannot be used by itself to repair a crack in a concrete pond.  G4 simply water proofs a concrete render)

Pond Liner Guarantee Details

The liners are covered against manufacturing faults. These liners are not guaranteed against damage caused by tree roots, underground animals, faults caused by installation or damage caused by pets (dogs, cats etc).

Flexiliner Guarantee

The liners are the same thickness regardless of the guarantee. The manufacturers have assured us that the product will remain stable for a minimum of 15 years up to 40 years plus dependent on where it is installed. (i.e. Southern Europe – higher UV)

We therefore have to insure ourselves against anything lasting longer than 5 years as the guarantee rests with us. It is this longer guarantee period (no quibble repair, replace or refund policy), that reflects the price difference.

PVC Liners Guarantee

The manufacturers have provided different guarantees based on the thickness of the liners.

The 15-year guarantee covers the 0.3mm thick PVC liner. Whereas the 30-year guarantee will cover the 0.5mm thick PVC liner.

Rubber Liners Guarantee

This guarantee will cover the EPDM/Greenseal, Butyl and Firestone liners.

The guarantee on the rubber liners is 40 years on liners up to 140 square meters. On liners over 140 square meters, this guarantee is reduced to 20 years.

If you require any further assistance, please contact us.