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Instructions for pond construction and pool construction made of GRP

Instructions for building a GRP pond

Many homeowners toy with the idea of ​​installing a pond in their garden. But once the decision has been made, the first questions quickly arise. Should it be a finished pond tub? Foil? Or would you prefer a pond that is built using glass fiber reinforced plastic (GRP pond)?

If you want to customize your pond system, you probably won't be happy with the pond tub. Pond liners also have their pitfalls. It is better to go straight for the GRP variant.

Glass fiber reinforced plastic (GRP) - robust, durable and perfect in appearance

For many years, glass fiber reinforced plastic (GRP) has been the material of choice when it comes to designing a pond. GRP is easy to process, durable, robust and also scores with a great look.
Pond lovers will be delighted - both with the handling and the result.

The advantages of glass fiber reinforced plastic

Anyone who chooses a GRP pond when building a pond will get a material in which several layers of reinforcing fibers have been soaked in (mostly) polyester resin and processed.
The number of laminate layers depends on the size of the desired pool and the preferred subsurface.

Other advantages of glass fiber reinforced plastic at a glance:

  • Embrittlement and UV resistant
  • Longer durability than pond liner
  • No unsightly creases and film edges
  • No damage during cleaning work
  • Easy lamination of cascades, streams and waterfalls
  • Individual design of bank and low-lying zones
  • Minimization of the capillary effect
  • Choice of topcoat color tone

The coating structure/subsurface of the pond

For the structure of the pond made of glass fiber reinforced plastic, a suitable substructure is required. The following substrates are suitable:

  • cement plaster
  • Masonry
  • Concrete

Important note:

If the subsurface of the pond is to be made of concrete, masonry or plaster, the coating may only be applied after about a month has elapsed!

Pond construction with fiberglass mat, polyester resin Resinpal 1705 and topcoat Resinpal 1305

Basically, there are several ways to get to a pond. However, many of the variants are extremely expensive. In addition, compromises in quality and appearance often have to be accepted.

In the following, we will show you an example of how inexpensive, fast and yet high-quality pond construction can be if you use GRP.

Material use

A fiberglass mat consists of chopped, non-oriented E-Glass Spain threads. It is provided with a silane size; a so-called polyester-based mat binder is used as the binder.
You need per m² and coating layer:

  • 1 m² glass fiber mat 300g/m²
  • Polyester resin / around 0.8 - 1 kg
  • Top coat / around 0.5 - 1 kg
  • Ev. Color paste / 10%

Production of the GRP pond - a possible guide

Once the pond has been excavated, the next step is to level the edge of the pond. Here you should make sure that all bumps, such as sharp stones, tree roots or similar are removed.
After the preparatory work, it is time to attach the pond. Concrete is the first choice for this, as otherwise the laminate structure will be problematic.

Important! Please ensure that the concrete is completely dry before further processing.

The laminate structure

You should choose the perfect weather for the day you set up the laminate - under no circumstances should the work take place in extreme sunlight. If in doubt, get a tarp to protect the work area from the sun. Here, however, you must ensure that the styrene vapors do not accumulate under the tarpaulin.

Before you start with the actual laminate construction, you must ensure that moisture from the floor or concrete cannot cause any damage later. For this reason, a thin layer of polyester resin must first be applied. The polyester resin has two functions: on the one hand it serves as a barrier layer and on the other hand as a primer.
It is recommended to mix only small amounts at first, as the processing time is limited to a maximum of 20 to 25 minutes. The polyester resin or the polyurethane primer / polyurethane resin can be applied with a brush or with a roller. In any case, the surface must be free of grease and dust.

After applying the polyester resin, the substrate must now dry sufficiently. The laminate structure should at best only d