Introduction: How to Make Faux Rocks

Picture of How to Make Faux Rocks

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.

Picture of 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.

Picture of 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"

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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.

Picture of 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

Picture of How the Rock Looks in the Garden

Looks pretty good!


stuffdone (author)2017-08-01

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!

Creativeman (author)stuffdone2017-08-01

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.

stuffdone (author)Creativeman2017-08-01

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.

Creativeman (author)stuffdone2017-08-01 one and make an instructable!

LA310 (author)2016-08-15

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.

LindaS402 (author)LA3102017-07-08

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)

AlejandroR26 made it! (author)2016-06-26

If youve ever been to the Steinheart Aquarium at the Academy of Science in San Francisco's Golden Gate Park before the remodel, you've probably seen the tidepool display. It took significantly longer than this this project, but it was done with chicken wire, cement and fiberglass feinforcement. It is a shame that it was removed and replaced by a plexiglass shadow of itself.

BeccaB4 (author)AlejandroR262017-02-19

Alejandro, the whole destruction of the original Natural History Museum is a shame. The new one is boring. I used to go to the old one all the time and spend hours there. Why did they have to tear it down. It was the greatest place ever and this new one, see it once and you're done. I have a membership to both the Natural History Museum and the art museum across the way and I never go to the Natural History Museum anymore. Its so sad. I miss the old art museum, but the new one is not so bad and its bigger, but the new natural history museum is just pathetic in comparison to the old one.

AlejandroR26 (author)BeccaB42017-02-20

I agree wholeheartedly. The new one looks like the Monterey Bay Awuarium. I miss most of all the tidepool and roundabout tank. I believe they needed to update the aquarium but in their endless wisdom decided to gut the place. Theonly thing that needed attentin was the round about tank. It leakrd endlesly. I really miss the old Aquarium!

Quester-59 (author)2016-06-27

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.

MickiW (author)Quester-592016-07-13

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!

Quester-59 (author)MickiW2016-07-13

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.

BeccaB4 (author)Quester-592017-02-19

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.

TeresaM7 (author)2016-06-30

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!

NadineG8 (author)2016-06-26

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.

Creativeman (author)NadineG82016-06-27

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!

PhotoJoeCA (author)Creativeman2016-06-28

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

Creativeman (author)PhotoJoeCA2016-06-28

Thank you, photojoe!

NadineG8 (author)Creativeman2016-06-27

Same as the first, on Instructables Web site :)

dpagan12 (author)2016-06-28

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

NadineG8 (author)2016-06-27

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

Hammerguy84 (author)2016-06-26

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!

weismonger4 (author)2016-06-26

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

A LOT lighter than a real one! X)

rortmanns (author)2016-06-26

OK, I'll bite....why? Anyone wanting rocks in Vic, Australia just send me a message, I have so many ricks on the farm that I don't want I'll help you load them. Please come take my rocks......

hawthorn1 (author)rortmanns2016-06-26

I would have to say obviously because a lot of people don't have these rocks and to buy them is very cost prohibitive. I am in this very position and thought this was a great article because I intend to do the same thing. Thanks Creativeman

rortmanns (author)2016-06-26

OK, I'll bite....why? Anyone wanting rocks in Vic, Australia just send me a message, I have so many ricks on the farm that I don't want I'll help you load them. Please come take my rocks......

captmarble (author)2016-06-26


New Cement is not supposed to dry. It is supposed to cure by keeping it moist for at least 7 days. For a interesting finish press rock salt into fresh surface, which will leave a pocked surface when it dissolves in rain etc.

least 7 days.

SusanP90 (author)2016-06-26

Great Idea, I can't wait to get started on a rock garden.

I will hollow out a place to put some plants. Flowers and herbs, maybe some creeping plants.

mona.blake1 (author)2016-06-26

It looks great! I will start with a bag of loose pebbles for weight, mold the cardboard to hold them.and add bits of broken glass in the concrete. This will look more realistic for Iowa. The weight will keep it from blowing away!

danzo321 (author)2016-06-26

You did a fine job if that's the look you want. I'd want them less pillow-y. Most older homeowners know too well that bags of concrete mix eventually become rocks, but the familiar pillow shape.. You can take a mineral hammer to them and get a craggy rock look. And if I were a burglar, I'd look under every too-perfect rock for the key!

elberry (author)2016-06-26

you can make a secret compartment to hide keys etc

paqrat (author)2016-01-21

If the rock not strong enough for someone to sit or climb on aren't you opening yourself up to liability problems? Seems to me something like this would draw neighborhood kids like a magnet draws iron filings.

jmorales32 (author)2016-01-12

Is the rock strong enough to hold an adult to sit on or no?

Questor (author)2016-01-10

Northwest Trek Wildlife Park, here in Washington, made a lot of their own rocks.

Some of them are actually 'camouflaged buildings' containing pumps and such.

RichardT27 (author)2016-01-10

During WW2 the Germans used fake rocks to hide the entrances to their under ground facilities.

nancee44 (author)2016-01-10

This is definitely not a fast-paced conversation with months inbetween comments. I have been diverted from rock construction with other endevors. Hopefully I will get at it in the early Spring.

cgrant (author)2016-01-10

How have you treated the bottom? Is it open and do you dig out some of the form material afterward?

nancee44 (author)2014-07-24

I just wondered how heavy the rock got to be.

Creativeman (author)nancee442014-07-24

25 t0 30lbs., I would guess

TimF10 (author)Creativeman2016-01-10

How large is this? I'm wondering if this process could be used build a larger rock. I've always wanted a small bolder in the front yard near the road with my house numbers on it.

krambrose (author)nancee442014-11-20

Yea, I'm sure it would have some degree of weight, just because of the different elements like sand and concrete. Plus, it probably depends on how big you make it!

milesnorth (author)2013-08-09

Thats a great rock. I just have to laugh though about saving money by making them. Is it that hard to find rocks where you are? Thats amazing! ( I am a rock maniac and have collected "real" rocks for years). I like it though. Thanks for the lesson. I plan on making a huge one with an old dog crate I have. Should make an interesting dog house I think.

MicheleB16 (author)milesnorth2015-09-13

did you make the dog house? I'm intreged

Creativeman (author)milesnorth2013-08-09

Thanks for the comments! Yes, it is very difficult to find rocks here...everything is fenced or paved it seems like. They frown upon taking them from the beaches and forest roads as well. Major fines. Like to see the dog house when done, good idea!

milesnorth (author)Creativeman2013-08-09

That honestly blows my mind a wee bit. I live in Alaska and collect rocks ABSOLUTELY everywhere i go. Have a bit of a thing for rocks (husband and father are both geologists). Wow! I am a hillbilly from Alaska. It is now official! Good luck in your rock hunting. If you every want to be in rock heaven visit AK :-)

krambrose (author)2014-11-20

Okay. I don't usually comment on these things, but this? This is freaking awesome. If I had a backyard I would definitely be making these for my tropical island themed backyard lol. Really cool!

theegghead (author)2014-03-27

A W E S O M E!!!!!

Antoninos Dad (author)2014-03-13

Love It! Will do in June!

lady4feet (author)2013-08-18

Just what I was looking for! I recently saw a fake rock at Lowes that I really wanted to get to cover a spigot in my yard but with a $90 price tag it is out of my price range. This is perfect, I even have some quickcrete in my shed.

About This Instructable




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