How to Make Faux Rocks





Introduction: How to Make Faux Rocks

About: Retired, doing art work now. Great. Have the time and the money to spend doing what I want to do.

In this instructible, I present my first attempt at making a faux rock. I tend to do things the hard way, but also consider everything a learning experience, an experiment, if you will. I have since learned there are easier methods to follow, but again, this is my first attempt. My eventual goal: landscape my front yard (southern CA) so that I don't have to water it ever again. Eventually, I will be able to build very large boulders using the techniques, and improvements I have learned, and save a ton of money on the rocks. Lets proceed:

Step 1: Gather Necessary Materials and Tools.

To make this rock, I started with a small corrugated cardboard box. I use lots of cardboard, so have a good supply on hand as well. Old newspapers for filler, some chicken wire, and of course cement/concrete tools such as spreaders, trowels, buckets, access to water, cement, sand and or mortar mix, etc.

Step 2: Design and Start Construction.

Thinking I could make a shape with cardboard as well, I made extensions out of cardboard that were glued onto the box with regular white glue. I let these sit over night to ensure that the glue was dried, and the bond was strong. It's sometimes easier to do these type of projects in stages, no hurry, no rush.

Step 3: Roughout "rock"

Seen in this picture is the rough rock, and the spaces in between the extensions are filled with newspaper. I even used some styrofoam as filler or extensions as well. It doesn't matter, you just want to make some support for your cement mix.

Step 4: Wrap Form With Chicken Wire

After enough newspaper and or styrofoam has been added to the "rock" form, it is all wrapped with chicken wire. I used the 2 inch size as it was cheaper, but 1 inch might be preferred. I made two layers of wire, thinking hole sizes would help hold the mortar better.

Step 5: Mix Your Cement/mortar

Following manufacturers guidelines, I use a mix of 3 parts sand to 1 part cement, with enough water to make a "stiff" mix of mortar. Using this basic formula, (it can be as much as 4 parts sand to 1 part cement), other variations can be tried. For example, I used a latex polymer tile set product as one part of the sand allotment. So it became: 2 parts sand, 1 part polymer, 1 part cement, plus the water. This adds some sticking power to the mortar mix, and makes it easier to control, I believe.

Step 6: Add Mortar Mix to Rock

Using a 3 inch spreader knife (drywall), I spread the mixture over the rock form. I started at the bottom edge of the form so that any loose mortar could be picked up and added to the rock before moving on. I set my form on a lazy susan turntable, covered in waste cardboard to make it easier to work around the form, and of course the cardboard caught the inevitable drips of mortar.

Step 7: Finish the Rock

After an overnight cure, the mortar was set enough that I could fill in any missed spots, or more commonly, places where the wire was showing through. To fill in these areas, I mixed some fresh polymer tile set, colored with cement colorant in a buff tone. This went on very easily, and towards the end, I added quite a bit of water to the mix, and using an old brush, covered the entire rock with the colored and diluted tile set. This dried very quickly, and I could stop here! To further experiment, I may try to add various weathering techniques,using acrylic paints to make "washes" of color, spattering with various colored paint, and so on. After curing for a few days, and finishing my experiments, I will seal it with a good exterior concrete sealer. This will help to protect the rock from the weather and prolong it's life.

Step 8: The Outdoors Rock.

After finishing as described, I moved the rock out into the sunshine to further dry and "season". Note it is still on the lazy susan so that I can rotate it throughout the day.

Step 9: How the Rock Looks in the Garden

Looks pretty good!



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Another method is to dig a hole in the ground the shape you want (upside down of course) then make a sticky mix of your concrete and line the hole. When dry just lift the hollow rock out and turn over. You can line the hole with plastic drop cloth and sprinkle in some colorant before adding the concrete and finish off later with other coloring methods if you like. The drop cloth provides nice handles with which to extract your masterpiece. No form to make!

3 replies

Cool, stuffdone! Creativity is amazing in that one idea always springs more ideas, ad infinitum! I was just talking with my daughter about this and recognizing that there is simply not enough time to do it all. If I were still doing these, I definitely would try your method, although it seems you would be limited to a rather odd, flat bottom "rock" that wouldn't look natural...hmmm, I don't know. Have you done this? Do you have pictures? If not, has anyone else? Would love to see some results.

A friend of mine and I cooked this up several years ago. No pics sorry we did that at his place but I moved about 7 hours away since then. You can dig the hole any shape, depending of course on the consistency of the ground. Soft sand you might need to add water so it holds shape. The plastic will help and also add texture if you don't smooth it out.

You would just have to try in your conditions.

I reserected this idea because I am getting ready (for two years) to build some kind of garden with pond and here in Florida rocks are as common as hen's teeth.

Good luck. one and make an instructable!

I tried this method but would rather just get a real rock.

There is a company called waterfallnow fountains up in canada that has fiberglass ones they mold from actual rocks that have a lot more texture to them.

1 reply

You can make these with more texture. I've been looking at several websites for DIY rocks and the one at wikihow showed how to make it look more like a real rock with crevices, indents, pockmarks and other feature so it looked more like a real rock. (Just and FYI)

Inventive Yes, however, try using construction grade " Spray-Foam," In a can, about $ 5.00, in most Hardware stores, some chicken wire, and some twist ties for shaping your rock. then coat the form with WALL-CREAT,

I believe you'll find it to be half the weight Yet jut as strong.

3 replies

Quester-59 What is WALL-CREAT, please? I have a project in mind for which it sounds perfect, but I can't find info on it? Thank you!

WALLCREAT, is a mixture of Portland cement & Fiberglass strands all chopped up and in the mix, As the name implies, it's made for making walls by simply stacking cement blocks dry, then WallCreat is prepared
and placed on the wall of blocks, covering them with at lease 1/4 inch
thickness, & allowed to dry.
Both Home Depot & Lowe's carried it, However,, if your in a hurry to make your rocks, try using .POST Quick set.

Hi, I want to make large hollow rocks that will work as a cat shelter for my outside cats. So I was thinking of using chicken wire and plaster of paris. Is this Wallcreat better? I would like something lightweight so I could create a bottom base and then the rock top which I could lift up to get the circular cat bed in and out to clean.

I saw another fellow who did this just using his trash, wadded it all up and secured it with fishing net. He lived near a fishery, so he could get the old netting for nothing, if I remember correctly. But I don't have the netting option, so this will work better for me, when I get there. Too much to do when you first buy a place! But I'm getting closer to the just aesthetics bit. Thanks for this!

I would suggest putting concrete on inside simply to make it stay put. In Wyoming, where I live, the wind is commonly at 30 mph. On other days it can be 50 or 60 mph(and these are mild storms ? wind getting worse with warming) so, unless ya want your rocks to become the neighbors rocks, I'd think of stayputability.

4 replies

Thanks Nadine...sounds like you have a time with the wind...we get some at certain times of the year, but not really sever. Would you mind telling me where you saw this instructable? I am curious after several years, I am getting several comments. Thanks in advance!

It was one of today's staff picks and went out in an email.

Same as the first, on Instructables Web site :)

I'm impressed I didn't think it would be that easy to make a cement based shamrock I have been using 341 ( South Bay plastics ) 2 part acetate plastic and impregnating foam with it , the result is a hard light shamrock that is paintable and looks good the problem with it is it is very light and has to be anchored . I think it can be the base for your cement process instead of the paper base , this stuff lasts I have parts on the driveway that are over 6 years old . my 2 cents

Just here on Instructables Web site. I did notice it was a few years old, lol. Still good idea :)

This would be a great idea for making a key safe outside! You could even sink a combination lockboxinto the bottom for added security! Great 'ible!

Yes, a more craggy looking rock would be better. But, how heavy is this faux rock?