How to Build an Indoor Rock Wall




Introduction: How to Build an Indoor Rock Wall

so you've got a comfy cozy wood stove, but now what do you put behind it? can't necessarily use dry wall, unless you like your house on fire. you could keep the cement board on, even though it's ugly as sin. why not put a rock wall in?

this Instructable will show you step by step how to put up a rock wall and make your house a home, all for under 50 bucks (if the cement board is already up).

you will need the following materials for a 8 x 12 wall

6 80 pounds of Type S Mortar Stucco Mix
4 pounds of 3 inch decking screws
30 one inch by five inch metal tie downs
150 or more rocks (see step one for specifics)
a five gallon bucket
a trowel (we found a flat drywall trowel worked best)
plastic sheeting (to put on the floor)

Step 1: Get Your Rocks

we're lucky enough to have a stream running through our property, so all we did was jump down into the stream and grab a bunch of flat rocks.

here are the keys for good rocks for a rock wall

flat (no bumps greater than an inch larger than the rest of the rock)
thin (no thicker than 2 inches)
relatively small (rocks should be at most one foot by one foot large, they are hard to put up when they are larger than this.

how many rocks will you need?
that depends on the size of the wall you are attempting. ours was 8x12 and we got approximately 150 rocks of varying sizes.

Step 2: Get Your Mortor

for our rock wall we needed six 80 pound bags of Sakrete Mortar/stucco type S mix

you will need High Strength!! do not attempt this project with medium strength or anything other than the high strength stuff, we tried it with medium strength and the stuff does not work well.

you will also need a five gallon bucket for the mixing of the mortar.

Step 3: Fix Up Your Wall

before you get going on your rock wall you will need to make sure that everything is good to go behind it. keep in mind that it is very hard to fix anything behind a rock wall...very hard.

we took down the cement board which was up prior to putting up the rock wall, it was a good thing we did, we found that there was a 3x4 section of wall that had no insulation at all. we put in some insulation and cleaned everything up behind it.

for this step you will need the following materials

three to four pounds of 3 inch decking screws
30 one inch by five inch metal tie downs (hardware stores have these, they might be called something else. they are wavy in appearance with three holes and are easily bent)
cement Board (if you don't already have it up)

-after cleaning out behind the wall put up the rhino board by cutting it to fit and screw it into the wall with decking screws.
-screw in the metal tie downs at every stud with at least two screws
-bend the metal tie down the slightest bit so that the mortar will be able to hug around the back and front of it.

Step 4: Get Your Work Area Ready

your going to want to lay down some sort of plastic sheeting or old sheet underneath where you will be doing your rock wall, it will get messy and it will be good to have something underneath it to catch all the extra mortar that falls off the rocks.

make sure that the rocks have had time (1-2 weeks) to dry off from being in the water and for the dirt on them to dry. then take a metal brush to each rock and scrub all the excess moss/dirt/spider webs off.

make sure you have all your rocks right next to your work area organized into different piles. we set up ours in four different piles. one for super small rocks (under three square inches) one for small rocks (between 3-8 square inches), one for medium rocks (between 12-20 square inches), one for extra large rocks (anything larger).

Step 5: Start Working

i should have said at the beginning that you should be knowledgeble of the game tetris when attempting this project, because you will need to fit rocks in to very odd places to do this.

1. mix up mortar in five gallon bucket.
-fill bucket about half way full with dry mortar then slowly add water while mixing till you reach the desired consistency. it should be somewhat hard to mix and have no dry parts to it at all. the mixture should lump up nicely on your trowel but slip off the trowel without too much help when held at an angle.
2. align dry rocks on wall the way you want them to go without much more than two-three inches between rocks.
3. butter the side of the rock to face the wall (see picture for example) don't bother buttering the wall i tried that at first but it didn't help much, in fact it didn't help at all.
4. when placing buttered rock on the wall make sure you press very hard and give it the slightest wiggle making sure you keep the pressure on the rock for upwards of 15-20 seconds.
5. when the rock is on the wall use the mortar to put an inch of extra mortar on top of the rock and make sure the line of mortar is even for the next row to go on.
6. when you are done the first row wait around 6-10 hours to start on the next row. we did two rows a day one right after breakfast and the other right after dinner.

extra notes...
-the mortar mixture might get a little dry during the process just add a little bit of water and mix it in.
-make sure you wipe off wet mortar off of the front side of the rocks with a wet towel, otherwise it will be wicked hard to clean up when you're all done.

Step 6: Row After Row After Row

it will take a while to get the desired result. it took us a little under two weeks to do our wall and we also took a couple nights off toward the end because we didn't feel like working.

you can see an example of a finished row waiting to dry in the picture here

when you are finished go through rock by rock and clean. we used a vinegar solution of 1/2 vinegar and 1/2 water to clean rocks, others may use bleach.

now just sit back and enjoy your rock wall.

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    6 years ago

    Looks good, how would this work for an exterior wall though? I have a project that needs an exterior rock wall and am looking for ideas

    A nice easy instructable, I would be sure to check your floor beams to be sure it can hold up the weight of thewall. I have also used chicken wire fastened on the back wall to give the concrete something to bond to. This will help prevent the wall from tipping over when you are putting it up.


    8 years ago on Step 6

    Hello, I love your wall and am hoping to replicate something similar. However, I dont understand what the "tiedowns" are and the purpose for them. Do you have any pictures of them and the way you put them on the wall? Holding rocks on? ???????? clueless in chugiak, alaska. THANKS.


    13 years ago on Introduction

    Wow, lay off of the caps lock buddy. And if you think you can lay rock better, please post an instructable on how to do so.


    13 years ago on Introduction

    heh heh I came her looking for a different type of Rock wall....


    My friend's dad built one of these. He included one or two realistic-looking lizards in among the rocks! They were so cool, and the were unobtrusive, so you didn't see them until you had looked at it a while. Fun!


    13 years ago on Introduction

    You need to reposition your hanging baby roaster, it's rather off-centered. It looks very unprofessional when it's not hanging directly above the wood stove. Plus, you can't truly replicate that mesquite flavor after the heat diffuses away from it.


    13 years ago on Introduction

    Nice job.

    There might be a few with construction trade experience that will say:
    • I hope you rebuilt the wall with the proper vapor barrier installed with the insulation.
    • Make sure you tape the backerboard joints with the proper alkali resistant fiberglass tape(not the drywall kind) to keep joint expansion from popping the rocks off your wall.
    • You could have used thinset to adhere the rock to the wall. And you do need to moisten the backerboard so it doesn't draw all the moisture out of the thinset as it cures. Mortar is more for filling in joints a vertical build like piling rocks or bricks on top of each other. That is why you need the metal ties to keep it from pulling away from the wall.
    • You shouldn't add water to a batch of mud after it has "slaked" or started its chemical reaction and begins to cure or dry, you will only weaken the mix.
    • You should use a notched trowel to "burn-in" the thinset to the wall and back butter the rocks/stones to help the adhesion. The proper size notch assures that the right amount of adhesive is there after you smush it up on the wall. A big glob of mud will take a lot longer to cure.
    • You let the wall set up and then go back to grout inbetween the rocks.
    • You can purchase spacers or improvise to keep the grout line consistent. You can put up a string line or use a 2x4 or level to keep the face even.
    • They do sell veneer-type rocks or even fiberglass fake rocks to install on a wall if you are worried about weight.
    • has a great forum for details on masonary and tiling subjects.

    Very nice instructable. One thing I would recommend, though, is that if you can get your hands on some cultured stone that may be a better option. And you may be able to get it with this same budget. Back when I was landscaping we did a number of new homes in some very nice neighborhoods. We would get there the day or week after they had just put the finishing touches on the house, and in this area that means cultured stone. I'd say that about 90% of the time they had a 1/3 or 1/2 pallet of stone left over that usually just got thrown out. Cultured stone is lighter weight, so it would make building a wall easier, for sure. Find a new housing development and see if you can make a deal with the contractors. Cheers! -DMC


    13 years ago on Introduction

    it would be nice to get some more detailed pictures...especially of the antique nail bit


    13 years ago on Introduction

    Very nice job and decent instructable. I'm considering the very same project, but was wondering something: Aren't you worried about all that weight? Is your floor joist hefty enough for all that added mass? I also assume your walls are standard 2 x 6 correct? You may want to explain to folks how/why the metal tie downs work. I'm familiar w/ them from past use, but I'm sure a lot of folks won't understand why you need them. Nice wall and nice instructable! j


    Looks like a great job, well done... One thing that might be handy for the larger rocks is cobbling together a vague hoist like assembly out of some pipe and castors, to make getting them in just the right place easier... Of course that's only if you start to get lazy...