Like so many people these days, we’ve been at home a lot more. And it’s given us the chance to spot potential projects for home improvement. This week, we thought it would be fun to come up with a way to hide some of the less-appealing objects that can be found in yards—like in-ground water valve covers!
Our solution? Cover it with a DIY fake rock that’s hollow and light enough to be picked up and moved when access is necessary. We made ours with mortar mix, a bit of wire, metal mesh and a little paint—all available at most home improvement stores. Below, you’ll find a list of tools and supplies and methods for building your very own fake rock.
Tools and Materials
- 60-pound bag of mortar mix
- Diamond lathe mesh
- Heavy gauge wire (1/8 inch)
- Roll of steel baling wire
- Large stiff brush for texturing
- Disposable paint brushes
- 5-gallon bucket
- Tin snips
- Pointing trowel
- Heavy gloves
- Acrylic paints
- Tarp or plastic sheet
STEP 1: Building the Wire Frame
Once you’ve got your materials together, start shaping your rock’s armature out of heavy-gauge wire—we used 1/8-inch gauge masonry block wire. The shape is only limited by your imagination, as rocks come in many forms and sizes. For this project, we wanted our rock to be hollow with an opening at the bottom. Your finished framework, in simplest terms, should resemble an upside-down bowl.
Begin by cutting a length of the heavy-gauge wire—ours was about two feet long—that you can bend into an approximate hoop shape. This wire is relatively easy to manipulate, and you can cut it with your tin snips or pliers. If you have any trouble, try gouging a couple of marks into it with your snips. Then bend it back and forth on the marks until it snaps in half. When you’ve got this piece of wire cut and bent, join the two ends by overlapping them a couple of inches and wrapping them with a short length of baling wire—pliers will help you twist the baling wire tight.
With your hoop shape set, cut a few arch-shaped pieces of heavy-gauge wire to form the top and sides of your rock—the lengths will vary, depending on how tall you want your rock to be. When you’re joining these pieces to the hoop, it sometimes helps to form a small hook shape on the ends to keep them from slipping off until you can wrap them tight with baling wire. Be sure to wrap baling wire wherever two or more pieces meet or overlap. This will give you a strong frame for the next phase of the project. When your armature is all together, you can bend and manipulate the shape even more to your liking.
STEP 2: Applying the Metal Mesh
The mesh we’re using is commonly known as diamond lathe. It’s made of thin strips of flat metal arranged in a diamond pattern. And it’s an excellent surface for gripping mortar, as it becomes impregnated within the different layers you’ll be applying. It’s commonly used in the construction trades as a plaster stucco backing on the outside of homes and businesses. It typically comes in 2-foot by 8-foot sheets, but you can also buy thin strips that are only six inches wide—and usually used to reinforce stucco on the outside corners of buildings. We chose the latter option, as our project is relatively small.
Lathe is easy to cut with tin snips, but consider wearing heavy gloves for this part. The cut edges of this material can be extremely sharp, and you may want to protect your hands as you shape and attach it around the frame of your rock.
We cut several strips to cover our rock completely—all between 1 to 2 feet in length. And we connected them to the frame with small
U-shaped pieces of baling wire, cut and bent into shape from 3-inch pieces. You’ll want at least a dozen.
To connect your lathe, lay it on the frame in the desired position. It sometimes helps to bend it and mold it a little. Then take one of your U-shaped pieces of wire and push it from the inside of your frame around a section of framework and through the holes in the lathe. When the two ends of your wire poke through, grab both at the same time with your pliers and twist them tight, cinching the lathe to your frame. Continue this process until the lathe is snug around your armature all the way around. It’s OK to overlap the pieces.
STEP 3: Applying the Scratch Coat
You’re going to want to apply two coats of mortar mix to your rock armature, and that can be messy, so be sure to use a tarp or plastic sheet on your workspace before you begin.
For both coats, we used Quickcrete mortar mix. But you can use any number of “ready Mix” mortar brands, as long as they contain both sand and Portland cement.
The first coat is known as a scratch coat and serves as a hard, workable surface you can apply your final layer to.
To start your scratch coat, empty about 1/3 of a bag of mortar mix into a bucket and then add a little water and begin mixing with your trowel or a small shovel. Be sure not to add too much water, as the mixture will become too soupy to apply to your framework. You can always add a little more mortar dust to stiffen the mixture back up. A good mixture should be about the consistency of oatmeal. Be sure to mix the mortar and water thoroughly. When you’re done, let it sit for a few minutes and then come back and mix it a little more. This will help ensure the chemical reaction that causes the mortar to harden.
When your mortar “mud” is ready, spread it onto your rock framework with your trowel—it helps if your framework is sitting flat on your protected work surface. The scratch coat should be between ¼ inch to ½ inch thick.
When the frame is covered completely, make a series of thin scratches with your trowel. This will give the final layer—the sculpt coat—something to bond to. The whole thing will look a little like a scratched-up frosted birthday cake at this point. Let it dry a day or two before applying the final coat.
Also, be sure to rinse your bucket and tools when you’re done. It’s much harder to clean these after the mortar becomes hard.
STEP 4: Applying the Sculpt Coat
Before mixing your final layer of mud, you’ll want to wet the surface of your rock thoroughly. This will improve bonding and help prevent the first layer from sucking too much moisture out of the final coat. Mix your final batch of mortar and apply it the same way you did for the scratch coat, covering the surface completely.
You’ll find that this final coat is easier to apply, as you’re now working on a hard surface that will let you build the mortar up in areas where you want it to be thicker—thicker areas will give you more room to carve details later.
With your surface covered, take your large brush and stipple the mortar before it gets too hard. This will help give it a convincing rock texture. Let the whole thing sit for an hour or so.
With your rock creation somewhat dry, come back in and carve a few cracks, striations and other details to make it look believable. The mortar, after it’s past the goopy phase, is easy to carve at this point. You can shave it with your trowel in areas and flake off sections to resemble the ageing process real rock goes through when subjected to the forces of nature. Clean your tools with water when you’re done, and let your rock dry for another day or so before applying paint.
STEP 5: Painting Your Rock
Paint your rock in several layers of acrylic or water based latex paint. The first coat you apply should be a solid, opaque layer. After this first coat has dried thoroughly, cover it with several coats of watered-down paint that get progressively darker. Be sure to let each wash of color dry before applying another. You can also try dabbing back some of these watery layers with a dry cloth. This lets the darker hues of paint sit in the cracks and textured areas, giving it a realistic look.
We base coated ours with an opaque cream color and then followed that up with several layers of watery browns and blacks. But don’t be scared to try your own color schemes that resemble different types of rock. We went for something akin to sandstone.
When your rock is totally dry, dry-brush a lighter color along some of the high points and edges. To do this, you want a relatively dry brush loaded with just a hint of your highlight color. Then take your brush, using the flat side of the bristles, and ever so gently drag it along the high points. It’s easy to overdo this part, so take it slow. You’ll find this dry-brushing technique helps pop some of your texture and details out even more.
Thanks for reading along. This fake rock technique can be adapted to lots of yard projects, including around ponds and pools. We hope it inspires you to have fun making your own creations.