There is a great myth promulgated out in the GRC manufacturing world that custom-made GRC planters need to be very expensive. In some specific cases it is true, but it is not necessarily always the case. To explain this, let’s have a look at some of the background issues that relate to the costing of custom-made GRC planters: -

1.       The difference between custom-made and standard size GRC planters.
Generally, custom-made GRC planters require a specially made casting mould that may not be reusable. Therefore, the whole cost of the casting mould needs to be recovered within the price of the custom-made GRC planter. On the other hand, a casting mould for a “standard” size GRC planter can be made to be reusable and therefore only a small portion of the initial cost of that mould needs to be recovered from each planter produced.

2.       The different types of GRC casting moulds.
GRC casting moulds can be made with many different materials such as steel, rubber, resin or wood but they don’t all cost the same to make or have the same life span. Steel is very expensive, but it can be reused many times over. Rubber is expensive and although it is great for producing intricate detail, it is easily damaged and therefore typically not able to be reused a lot. Resin tends to be a good balance between cost and reusability and wood is the least expensive with the least reusability. The type of mould a manufacturer chooses to use will depend on the manufacturer’s manufacturing process and competence in the material to be used.

3.       The manufacturing process used to make GRC planters.
GRC manufacturers typically use either the spray-up or pour-casting method to produce GRC planters. With the spray-up method, the planter casting moulds have open walls to which the GRC slurry is layered where as with the pour-casting method the planter casting moulds have double walls within which the GRC slurry is poured. The spray-up method generally produces a much stronger end product than the pour-casting method and the moulds are also much less expensive to make. GRC manufacturers that use the pour-casting method will generally avoid custom-made GRC planter options as much as possible because the double walled moulds are quite expensive to make and store.

Some manufacturers choose the pour-casting method to cast GRC planters because it requires less labour and expertise in the actual manufacturing process than the spray-up method.

4.      The cost of labour to make casting moulds.
Making GRC casting moulds quires a high level of expertise and experience no matter which mould making method is used. Therefore, the labour cost in making them is very significant and will also vary based on the method used.

5.       The supplier’s preference
GRC planter suppliers generally prefer that customers purchase planters from their standards range because the orders are easier to manage through the supply process. Therefore, there is a tendency for some suppliers to cost custom-made projects high to induce customers to compromise with a less suitable standard size. This is not always the case because the supplier may simply be looking for ways to help the purchaser to save money or reduce the delivery time. However, it is an issue to watch out for.


Custom-made GRC planters will most likely be comparatively expensive if the manufacturer making them: -·        
- uses the pour-casting production method
- makes the casting moulds out of either steel or rubber
- has high labour costs
- has a standard range of GRC planters that it would prefer you to purchase

Custom-made GRC planters will not be much dearer than standard sized planters if the manufacture making them: -
- uses the spray-up production process method
- makes the casting moulds out of either resin or wood
- has low labour costs


It’s pretty clear who is driving the myth that custom-made GRC planters need to be very expensive. It’s the manufacturers, or the resellers for those manufacturers, that don’t want you to order custom-made planters because their manufacturing processes, mould making methods and/or high labour costs make their custom-made prices uncompetitive. However, custom-made GRC planters do not need to be a lot more expensive than standard sized planters if you choose the right manufacturer.