How to Build Fake Rock With Cement

Creating your own fake rocks from cement can be an advantage to collecting the real thing, as you can adapt the size, shape, color and texture to suit your personal needs. The process is easy, and once you have your basic mold you can create as many perfect rocks needed for your landscaping projects.

Things You'll Need

• Real rocks (at least one)
• Petroleum jelly
• Piece of cardboard
• Contractor's foam sealant
• Carpet knife
• Cement
• Texture materials such as leaves, sand, pumice, glass (optional)
• Food coloring (optional)
• Heavy sand paper
• Spray sealant or varnish (optional)

Instructions

1. Choose at least one real rock that is the size and shape you would like to duplicate. Clean the rock well to remove any debris and then cover it with a thick layer of petroleum jelly so that it will come away easily from your mold. Place the rock on a piece of cardboard and cover it thoroughly with contractor's foam sealant and allow to dry.

2. Cut the foam sealant with a carpet knife, making a smooth circular cut around the thickest part of the rock so that you have two halves of your fake rock mold. Apply a thick layer of petroleum jelly to each part of the mold.

3. Mix your cement according to the package's directions and add any extra material you like. You can add extra sand or pumice to give your rock more texture. You can even add a few drops of food coloring to give your fake rocks a tint of color.

4. Pour the cement into each side of the mold and then place the two pieces together. Place the fake rock mold in a warm, sunny location to dry. After a few hours when the cement has set, remove the mold and use heavy sand paper to remove the ring where the two molds met. Leave the rock in the sun until completely set, usually at least 24 hours.

5. Seal your fake cement rocks with a light layer of spray sealant or even varnish to protect them from the elements.