Pond construction - advantages & disadvantages of various systems

Pond liner, hard shells/prefabricated pools or tiles are often used for pool and pond constructions. An alternative to these conventional materials for pond, pool and roof coatings is offered by the "GRP coating" with glass fabric in combination with epoxy resin and/or polyurethane top coat. Such a GRP coating is not only easy to apply, but is also convincing due to its long-term advantageous properties for pond and pool construction as well as roof coatings! Below you will find detailed information on the individual materials used for a GRP coating:

 What are the advantages of our PU topcoat? 

The 2-component polyurethane topcoat HP-PUR-PLUS was specially developed for permanent water loads in pond and pool construction. It has a long-lasting colour stability and an excellent fullness of the paint film.  

✔ brilliant colours
The polyurethane topcoat is applied as a final topcoat to the epoxy resin-reinforced glass (GRP). It is available in almost all RAL colours, so that you can design your GRP pond, pool or roof coating according to your individual wishes! In addition to the coloured effect, the polyurethane top coat offers long-lasting, high UV protection. So you will enjoy your GRP pond, pool or roof for a long time!
✔ very good resistance
Another advantage of the polyurethane topcoat is its resistance. HP-PP is very resistant to weathering and permanent water exposure, but also to chemicals such as chlorine (if the recommended dosage is kept)!
✔ easy application
In addition to its advantageous chemical properties for pond and pool construction, the PU topcoat is also easy to handle. It is applied in two coats by roller or brush (suitable paint rollers: HP-L1032 and HP-L1034) and is ideal for private users who want to build a pond or pool themselves. 

detailed information on the PU topcoat can be downloaded here:
Topcoat HP-PUR-PLUS    [PDF]

 What are the advantages of GRP (glass reinforced plastic)? 

"GRP" stands for "glass reinforced plastic" - a composite material made of a plastic matrix (epoxy resin) and glass fabric. The properties of GRP are particularly advantageous when building ponds and pools.

✔ more durable than any conventional film.
A GRP coating is resistant to animal claws, beaks, stones, impact loads and garden tools. It therefore offers significantly greater stability/strength and is above all more durable than conventional pond liner.
✔ wrinkle-free pool design
Particularly important with a GRP pond coating or pool coating is the careful incorporation of appropriate connections such as skimmers, drains or nozzles. With a GRP coating, these can be laminated in without any problems and without creating wrinkles in the surface. In addition, steps, landings and corners of the pond or pool can be laminated without wrinkles when coated with glass fabric and epoxy resin.
✔ problem-free "do it yourself" system solution
A GRP pond, pool or roof coating is ideal as a "do-it-yourself" solution for the private user. In our range, we have put together suitable GRP coating sets in different sizes and colours. These contain all the necessary materials and assistance for implementation. In addition to GRP instructions on "how to build a garden pond" and videos on how to build a pond yourself, you will find many pond building tips in our FAQ section. Furthermore, our application engineers for pond and pool construction will be happy to help you with any questions you may have by phone.

 What advantages does epoxy resin offer? 

Our 2-component epoxy resins are very suitable for pool, pond and roof coatings due to their properties. We have the right epoxy resin in our range for every application, both for the primer and for the GRP laminate and top coat.
✔ free from solvents
Our epoxy resins are free of solvents, so there is no major odour nuisance and work can also be carried out indoors without any problems. In addition, insulating materials (such as Styrodur®), which are often necessary for pond, pool or roof coatings, are not attacked.
✔ very good adhesion properties
Due to their high adhesive strength, our epoxy resins can also be used on existing substrates (e.g. polyester laminate, wood, stone and many metals) and convince with their good adhesion.
✔ very good mechanical properties and high chemical resistance.
Compared to conventional polyester laminates, composites with epoxy resins have significantly better load-bearing properties, both mechanically and chemically.
✔ very low water absorption/excellent osmosis protection
Epoxy resins are characterised by their high water vapour impermeability. Therefore, they are ideal for use in areas with continuous water exposure, such as pond and pool construction!
✔ can also be applied in sunlight
In contrast to polyester resins, epoxy resins can be processed under sun or UV radiation without any problems. With polyester resins, the rays interfere with the curing process on the surface.

You can download instructions for working with epoxy resins here:
Working with epoxy resin    [PDF]

 disadvantages of alternative materials: 

- disadvantages of foil sealing
 Pond liner sealing
  • In retrospect, pond liners are often more expensive and more complex than initially assumed!
    Pond liners with low thickness are quite inexpensive, but in the end liners with significantly higher layer thickness are usually recommended for building a pond yourself. Further costs arise from the additional reinforcement, the protective fleece/swimming pool fleece as well as root barriers and bank mats, which are not necessary with a GRP coating. Other disadvantages are the formation of wrinkles and the extremely difficult handling due to the bulky rolls of film and the time-consuming welding. In addition, flanges must be purchased to seal the connections.

  • Limited design possibilities in pond construction!
    An ideal basis for building a pond yourself with pond liner is a simple and straight substrate that does not have any complicated geometries. The design options for the pond are therefore severely limited. In addition, wrinkles can quickly form or problems can arise when welding the pond liner. With a pond liner made of GRP, on the other hand, individual shapes and geometries can be implemented without forming wrinkles!

  • Pond liners are temperamental to mechanical stress!
    Simple pond liners are very temperamental to external influences such as claws, beaks, stones, garden tools or toys and can therefore be damaged quickly. Necessary costly repairs are spared with a pond liner made of GRP, as it has a high level of strength and stability!

  • The choice of colours for pond liners is limited!
    Standard PVC pond liners are only available in black, so the design options are very limited not only in terms of shape but also in terms of colour. For this reason, we recommend a GRP coating for building your own pond, where the final top layer can be designed in almost all RAL colours. In this way, individual wishes and colour ideas for the pond can be implemented without any problems!
- disadvantages of hard shells and prefabricated pools
Prefabricated pools
  • Transporting large hard-shell pools/prefabricated pools is difficult and cost-intensive!
    Because hard-shell pools/prefabricated pools are manufactured in one piece, cost-intensive special transports are often necessary. In addition, placement in the garden is sometimes only possible with the help of a crane. The materials for a pond or pool coating with GRP, on the other hand, can be conveniently delivered by parcel service or freight forwards!

  • The shape of hard-shell pools/prefabricated pools is limited!
    While individual wishes for the shape of the pond or pool can be taken into account when building a pond or pool yourself with a GRP coating, the choice for hard-shell pools is often limited.

- disadvantages of liquid film
Liquid liner
  • A pond coating with liquid liner often leads to leaks!
    Due to the low strength, even slight stress cracks transfer to extensive coating surfaces of the pond or pool. As a result, leaks quickly form on the surface, the repair of which does not only cost nerves, but also time and money!

  • Liquid liner is not suitable as a simple solution for private users!
    For a pond or pool coating with liquid foil, it is best to call in an expert, as experience in the field is necessary for proper waterproofing. Meanwhile, a GRP coating in the area of pool and pond construction proves to be an ideal "do-it-yourself" solution for the private user. Our GRP instructions on the subject of "How do I build a garden pond?", videos on how to build a pond yourself and the personal consulting service of our application technicians serve as assistance here.

- disadvantages of concrete or tile pools
Concrete pool
  • A pure concrete waterproofing is coarse-pored and therefore susceptible to deposits!
    The deposition of microorganisms, bacteria and algae in the pores of the concrete increases the maintenance effort of the pond or pool enormously. In contrast, the pond or pool coating with GRP is characterised by its particularly smooth surface, which is less susceptible to deposits in this way!

  • Concrete pools are not 100% waterproof!
    Especially in pond and pool construction, the materials are exposed to a high continuous water load. Since concrete is not 100% waterproof after intensive processing, water can penetrate in small amounts over time. This causes stress cracks to form in the concrete or in the applied tiles. A GRP coating, on the other hand, meets the requirements for high exposure to water and is therefore ideal for long-lasting pond and pool projects.

- disadvantages of polyester glass mat coatings
Polyester glass mat coating
  • Polyester resins may not be shipped to private customers!
    Due to an amendment in the Chemicals Prohibition Order, the shipment of polyester resins to private customers is prohibited due to certain chemical substances.

  • Polyester resins must not be processed under sunlight!
    For larger projects in pond and pool construction, elaborate sun protection constructions must be built in order to process polyester resins without problems. With polyester resins, the sunbeams or UV rays interfere with the curing process on the surface. Epoxy resins, on the other hand, can be processed under sunlight without any problems and are therefore more suitable for building pools and ponds yourself than polyester resins.

  • The processing of glass mats is very time-consuming and a lot of resin is used!
    Glass mats are not only difficult to process, but also have a very high resin consumption, so that additional costs are incurred for the pool or pond coating. In addition, this structure must be treated further (sanding, sealing), as individual fibres stand up during processing. If this is done incorrectly, damage such as osmosis can occur, which does not occur with a coating of epoxy resin and glass fabric.