| There are several ways to make fake rock or faux | | | | the shape with some of the rubble, then more |
| rock and boulders all yielding good results. | | | | concrete, then more rubble and so on until you have |
| The method you select to make fake rock is usually | | | | the rough finished shape. |
| based on what is the cheapest and most readily | | | | To make fake rock with this method it is a good |
| available filler material you have available on site. Very | | | | idea to be doing several rocks at the same time. |
| realistic faux rocks or boulders can be made using | | | | While allowing one lot of concrete to set up you can |
| any of the following filler materials. | | | | be working on another rock. Once the rough shape is |
| Building Materials and Methods | | | | finished and set up, the application of mortar can |
| · Building rubble such as second hand bricks or | | | | commence. |
| crushed concrete | | | | Use a throwing action for the mortar as it adheres |
| · Recycled real rocks | | | | better than merely trowelling it on. Additional layers |
| · Polystyrene | | | | of mortar also adhere better to the rough texture |
| Alternate methods to make fake rock involve using | | | | left by the throwing action. Start the finishing coats |
| some way of giving an approximate shape to the | | | | from the top and work your way down. If you are |
| finished rock before the application of the mortar. | | | | working on two rock shapes side by side be careful |
| · Chicken wire bent to shape is widely used for the | | | | to emphasise the join lines between the rocks. |
| smaller rocks | | | | Definition is very important with these seams to give |
| · Cardboard boxes of all sizes can be cut to shape | | | | the rocks a natural appearance. |
| · Rebar and expanded metal | | | | Hollow Rock Construction Methods |
| For repetition of the same design the use of moulds | | | | Chicken Wire |
| is recommended. | | | | This method is of use for smaller hollow rocks. |
| · Casting from a mould | | | | · Cut and wrap the chicken wire to the rough shape |
| The material and method you use to make fake rock | | | | of the finished rock. |
| will be the one that you consider to be the fastest | | | | · Bend any sharp ends of the wire inwards with a |
| and cheapest to give you the best finished result. | | | | pair of pliers. |
| The time the job takes is based on how much detail | | | | · Now cover the wire with some newspaper soaked |
| is required. The more definition and finish you give to | | | | in 50/50 diluted white woodworking glue and allow to |
| each rock the more time is involved. | | | | dry. |
| To make fake rock of larger proportions such as | | | | · Cover the wire with several layers of plaster of |
| garden boulders, a smoother, low detail finish looks | | | | paris bandage which has been briefly soaked in water |
| best while smaller decorative rocks require more | | | | and allow to dry. |
| work and materials. | | | | · Decorate with diluted acrylic paint mixed 50/50 |
| A garden landscaping job will often require the use of | | | | with sand to give a rock like texture. |
| several of these different finishes to give the | | | | Re-bar and Expanded Metal Construction |
| required natural look. The more methods you are | | | | This is the most widely used method to make fake |
| experienced in using to make fake rock the better | | | | rock which is hollow. Using this method rocks can be |
| the finished quality of work you will be capable of | | | | shaped to cover taps, pool pumps and other |
| producing. | | | | equipment. Due to its ability to be easily shaped and |
| Solid Fill Method | | | | retain structural integrity, it can be used to make |
| While this is possibly the slowest and most expensive | | | | anything from a waterfall to a garden arch. |
| method to make fake rock it is still the most widely | | | | Once you have the shape set up with the re-bar, the |
| used due to the availability of used building material | | | | expanded metal can be attached. Tie it to the re-bar |
| on most jobs. Not being of hollow construction it also | | | | every 100 to 150mm. Make sure it is not loose. Coat |
| gives the closest sound and feel to natural rock. | | | | the structure with two 3 to 4cm coats of mortar |
| The materials used in this type of construction are: | | | | mix leaving a minimum of an hour or overnight |
| Building rubble. | | | | between coats, depending on the temperature of |
| This is usually free or is already on site ready to be | | | | the day. Add texture to the project using similar |
| disposed of. It is essential to hose it down before | | | | methods to the solid fill method. |
| use to ensure proper bonding. | | | | Cardboard |
| Second hand bricks and concrete blocks | | | | Using a mix of large and small cardboard boxes cut |
| Even if you have to purchase these it is still cheaper | | | | to shape it is possible to build up a firm structure |
| than using concrete. Difficult shapes such as | | | | very close to the desired rock shape. Used boxes |
| waterfalls are also easier to construct due to the | | | | are readily available free from local stores and |
| regularity of their shape. | | | | provide an easy and economic way to make fake |
| Polystyrene | | | | rock of all shapes and sizes. |
| This is a waste material used for packing and readily | | | | · Make the structure rigid by stapling, wiring, |
| available free from your local stores. It can be cut to | | | | screwing or gluing the cut box shapes together to |
| shape very easily and lowers the weight of the | | | | form the rough outline of the desired rock shape. |
| finished faux rock. It holds the shape of the rock and | | | | · Coat the boxes with two coats of acrylic polymer |
| does not slump with the weight of the mortar, unlike | | | | stabilizer mix, using a brush to throw the mix directly |
| some of the other filler materials. | | | | onto the cardboard. If too much is applied at once |
| Recycled rock and other natural materials | | | | there is a danger that the cardboard will be soaked |
| These are often on site and easy to use giving very | | | | and collapse. Allow the cardboard to dry between |
| natural shapes. Wash before use. | | | | coats to give it the required strength to support the |
| · If the material being used is in small pieces it can | | | | finishing mortar mix coat. |
| be placed in plastic bags and stacked for ease of | | | | · The cardboard can now be coated with a 80mm |
| assembly. | | | | coat of mortar mix applied in two 40mm coats. |
| · Cut open and expose the filler material | | | | · The structure can now be textured, stained and |
| · Apply two coats of the acrylic polymer stabilizer | | | | sealed. |
| mix. This should be thrown on using a brush and is | | | | Casting from a Mould. |
| designed to ensure the structure is rigid before | | | | For producing the most accurate reproductions of |
| applying the finishing mortar mix. | | | | natural stone there is nothing to beat the castings of |
| · Apply two 40mm coats of mortar mix. | | | | faux rock from a mould. They are exact duplicates |
| · Finish as with other techniques. | | | | of what you have seen in nature. The same rock can |
| This type of rock is very easy to construct. It also | | | | be produced over and over. Moulds can be made |
| uses plain concrete and a basic mortar mix for the | | | | using latex or silicone usually with a plaster back up |
| final shaping to further save any complications. First | | | | mould to retain the original shape. |
| build a small concrete base for the rock, then build up | | | | |