The-Artistic-Garden's Blog

Questions About How To Construct
A Hypertufa Rock Formation For A Waterfall

I received an email from an enthusiastic hobbyist who wrote:

Hello, first of all let me say thank you very much for such a great and informative site! I’m writing because I need to get some of your hypertufa how-to advice.

I am making a waterfall with either hypertufa or concrete and I wanted to make a rock-face resembling a cliff. I have been looking at some nice concrete trees and cliffs but I’m seeing a lot of welding and rebar – I realize that’s important for large structures.

My structure is just over 1 meter tall, and under half a meter wide, and I want to make it as light as possible. There will be a waterfall. The biggest issue is that I really want the entire structure to be hollow.

I think I might use some wood/bamboo/styrofoam/chickenwire combination as an armature. I know I have to cover it with the wire mesh cloth strips. What I don’t know is if I can remove the armature after the first stages of curing?

Am I supposed to cover the entire armature with plastic and a release agent before I put on the wire mesh? But if I am wire-tying the mesh onto the armature, would I have to untie it before removing it or is it supposed to be permanent? It would sure make a lot more weight and mass, and would make the structure very ugly if seen from the bottom.

The good part about this particular waterfall is the back will be against a wall, so could I just leave it a half shape form in a trough style, and then lift it up on its side? and then could I later cement that waterfall to a base? The base will extend about 1.5 meters beyond the front, so I would prefer to make it all upright from the beginning.

So that’s my question – can it be done upright and can the armature be removed afterwards? And any ideas as to the best armature material? I would prefer not to weld.

I saw some beautiful indoor waterfalls with welding of wires thinner than rebar, used in conjuction with something like chickenwire, and I could see it was mostly hollow. I didn’t see any other filling other than wire mesh beneath it … but I don’t undertstand how they removed the filling afterwards, or how they made this big hollow rock face.

I kind of guess that it’s hollow because they’ve removed the form, but it could be that the wires are really secured well, but I still don’t see how they could form it through the chickenwire, keeping the chickenwire hollow.

One more quick question, can it be used as a waterfall before the 1 month curing process? Say after a week?

I would greatly appreciate any knowledge or how-to tips on this subject, or a point in the right direction. I am very interested in making large hollow hypertufa and concrete rock structures for waterfalls in the future as well.

Thank you! “Chinarabbit”

My reply:

Hi Chinarabbit:
I hope I can answer all your questions. And thanks for the kind comments about my website – I appreciate that.

Whew … I give you credit for taking on a large project like what this one will probably be. You have pretty much answered your own questions, in that there has GOT to be some sort of inner structure onto which you will apply the hypertufa or ‘crete. Whether it is a welded rebar frame (yes … I understand most of us just don’t have this option, due to not having the welding equipment and/or the money to afford to have one made for us), or a chicken wire contraption such as you described … based on what you want to do, and to have it LAST A LONG TIME you will apply the mixture to the frame.

I will highly suggest that the frame NOT be removed, as it will be an integral part of the final object.

Now … on a side note, though I really don’t have a 100% complete idea of what you want to do … the “inner structure” could be nothing more than chicken wire. If you wad up plastic (bags) and fill the entire inner cavity of the form with it, the “wads” would act as a temporary barrier to keep the wet mixture from falling through the chicken wire. When partially cured, the plastic wads would be removed, thusly what you have is a reinforced ‘tufa or concrete structure. Follow me here? And you are making the entire structure lighter in weight, which is also one of your concerns.

I am guessing chicken wire is going to be an integral part of the inner structure, in order to get a curved surface.

In addition, you’d better use a reinforcing agent of some sort to make a more durable recipe. Again … longer lasting for you.

And lastly, DO NOT RUSH the curing process! (30-days is about what it needs to be.) That is one of the biggest reasons for failures! Plus, if plants and more importantly fish are going to be in your pond … you have GOT to leach out the lime from the cured structure.

I hope this helps some. Post more if I’ve not clarified anything enough for you. Let us know how your project progresses! Good luck!

~~~

Chinarabbit replied:

Thanks for your time and response, it’s been very useful. I am ready to get started!

I have already bought several large styrofoam sheets of different thicknesses and a lot of bamboo skewers. I thought I’d follow this procedure:

1. just carve the basic shape I need with the styrofoam, securing the pieces together with the bamboo skewers, making a solid structure, because I’ve decided to leave the back open, and just have a sort of half-shape with a rock face and an open back and bottom on the finished product. Actually there will be 2 rock walls, at opposite ends of the structure, with their back to a plywood wall, and a concrete riverbed/planter/pond along the bottom connecting the two.

2. wrap the structure in large plastic bags for release (maybe even some vegetable/mineral oil mix on top of the plastic, or is it unnecessary if I have plastic?)

3. wrap that it in a chicken wire frame…

4. put fine wire mesh strips over the chicken frame (do you think this is important? or can i do without it? I thought the fine wire mesh might make the concrete more stable, but it would also make the chicken wire unattached to the concrete, perhaps the chicken wire would fall away because it didn’t penetrate the fine mesh?)

5. mix the concrete and apply a layer 3 inches thick and carve out the shape of rocks. can you recommend a replacement for the fiber strands? I’m an American living in China and not sure i will be able to find those, can they be made from something else?

6. after it begins curing I would remove the styrofoam, leaving only the wire mesh/chicken wire attached beneath.

7. keep misting it. This project will be behind glass, and include an automatic sprinkling system, maybe I will just install the glass and let the sprinklers mist it for a month.

So, I have those minor issues. Thank you Claudia for your in-depth responses. I would greatly appreciate your final input on these last little details.

Once again they are:

A. what do you think of the styrofoam form leaving a half-shape waterfall?

B. is oil useful on plastic?

C. wire mesh on top of chicken wire? or just one or the other?

D. replacement reinforcer other than the strands you mention in your site.

E. also, should I apply a layer of concrete/Elmer’s glue mixture to get finer detail? Or is one layer sufficient for waterfall detail? And would the outer layer weaken the structure?

I have seen several other forms, such as overhead tree branches, which have had an outer layer applied and also seems to fall off exactly at the seam between the two layers, who knows if they used any glue. Probably not, it’s in China and I don’t think they’ve read your site. lol

So anyway, thanks again for all help and ideas. Your The-Artistic-Garden.com is by far the best website on hypertufa how-tos that I have found.

You are a very generous person to offer such wonderful advice in the spirit of helping and giving and sharing. So many other sites on this subject regard it as quite an expensive little secret of sorts. I’ve recommended your site to all my family and friends interested in gardening.

Keep it up – I hope it’s a permanent site that will last for years to come.

~~~

I replied again:
Hi Chinarabbit:

Wow, you live in China! I just love the internet – such an incredible way to meet people from all over the world.

OK, you are keeping me busy here.   Let me try to answer everything:

A. Styrofoam can be a great sub-surface or inner form that can be completely covered in ‘tufa … so this sounds OK;

B. Nope — don’t need the oil. The plastic should just pull away from the ‘tufa;

C. I “think” (I am using my best judgement here–but it is ultimately up to you!!) the chicken wire, mooshed inbetween the ‘tufa will be just fine — no need for the mesh strips;

D. You can use a bonding agent (read more here: hypertufa & concrete bonding agents explained) to strengthen as opposed to the fibers;

E. 1st Q answered by “D”; I cannot accurately guide you if one layer will be enough — you did say 3-inches — that should be fine, but again, I am not there along side you perhaps the layer on the branches were not properly prepped before whatever was applied to them (you’ve not mentioned?), thusly the material is falling off. It isn’t adhereing to the sub-surface properly.

I hope I answered everything. Umm … one thought that I must mention that jumped out at me. You mentioned a plywood wall behind this new structure? I am going to assume you know constant moisture and/or direct contact with water is NOT a good thing for plywood. I am hesitant of you using plywood with a waterfall construction.

And, thank you so very much for your kind compliments. It means a lot to me that people do appreciate the attention I try to put into everything I write and share online.

Good luck with this project and I do hope all my “hypertufa how-to” tips have helped steer you in the right direction.

A Very Frustrated Hypertufa Trough Maker
Seeks Helpful Advice & Answers To Her Problem

I received this email plea for assistance from “Laughing”:

Please help me Claudia! I have tried the hypertufa beginner recipe several times and my ‘tufa troughs and containers break apart while taking them out of the molds I am using, which are simple large plastic containers – nothing fancy or anything. Just rectangular containers.

Only 2 of my hypertufa troughs out of about 20 have survived! Any thoughts?

Help please. Laughing

My reply:
Hi Laughing:
Oh dear … sorry to hear about this and I know you really aren’t laughing! (But if you are – good for you! Life has too many other things to get stressed over … hypertufa isn’t one of them! )

Unfortunately, I can’t nail down where the problem lies, as I haven’t a clue to everything you are doing, from A to Z. But my BIGGEST guess, based on years of experience in helping other beginners with the same problem is this:

??Are your ratios of dry ingredients to water correct??
This is normally the #1 culprit that causes disasters.

I will also ask are you unmolding them too soon? Or perhaps you’re not providing enough moisture during the cure process? You should make it a point to peek inside the plastic bag you’ve wrapped your troughs in to see if condensation is collected on the inside of the bag every now and then.

Perhaps my reply doesn’t sound too helpful, but really … either a too dry or too wet mixture is what normally causes the problems. It *sounds* like maybe too dry a mixture is why the portland can’t set-up nice and strong, since you say they fall apart. Even though when you apply the mixture it seems OK, after the item(s) start to cure, that’s when the issue of not enough water in the hypertufa recipe becomes apparent.

If your mixture was too wet, most times it would start slumping off the sides of your form and you’d know almost instantly you had goofed and used too much water in the recipe.

My only other stab-in-the-dark guess is are you really using the right ingredients as listed in the beginner’s recipe?

Good luck and I hope this sets you on the right path.

Hey “The-Artistic-Garden” readers … want to learn about ‘tufa trough making? Then click this link to read my instructions on how to make a hypertufa trough. And remember to be mindful of the ratio of water you use in your recipe!

What Is A Good Substitution For Peat Moss?
It Is An Environmental “No-No” In The UK

I received an email from Mike who asked:

I am very interested in your excellent web site and in particular hypertufa recipes and projects.

I am based in the UK and peat is a big “no-no” environmentally. Can you recommend a peat substitute for hypertufa recipes? What is the function of peat in hypertufa? Sorry to bombard you with queries.

Best wishes. Mike

My reply:
Hi Mike:
Thank you for contacting me.

Interesting, I did not know peat moss is a complete “no-no” in the UK! (How come, if I may ask? There is so much of it in the world it certainly is a “renewable” plant/product, and I have read that Canada, for instance, does practice controlled harvesting.)

Anyway, you can use coir. I am not personally acquainted with using it, but I am aware some folks do use it as an acceptable substitute for the peat moss. I do have detailed information about a coir based hyperturfa recipe on my website (thanks to your inquiry.)

But, here is the basic recipe. As is most often the case with hypertufa recipes, you may need to adjust a ratio of one of the ingredients (normally it’s the amount of water used or not used). Try a smaller project before you tackle a huge project!

Basic Hypertufa Recipe Using Coir In Place Of Peat Moss
3 parts coir (coconut fiber)
2 parts Portland Cement type I-II
3 parts perlite
(water as needed for proper consistency)

To read all the information, please go to: Hypertufa Recipe using Coir.

About the purpose of the peat in hypertufa: over time, if left out in the elements (your garden), the peat will decompose, leaving pits and crevices. This replicates real Tufa rock, which is the whole idea of folks working with hypertufa. I will assume the coir will decompose, but maybe will take a little longer to do so??

I do hope this info helps.

~~~

Mike emailed me back and said:

Thank you Claudia for all the information.

There’s still plenty of peat around in all purpose compost here and you can still get peat but it’s known as being an unsustainable resource and all the big retailers have policies to reduce and eradicate it over the next few years.

A Garden Art Crafter Asks
“What Release Oil Do You Recommend?”

Harold emailed me and asked:

What is the barrier or release oil that you recommend for hypertufa or concrete garden art projects? Thanks!

My reply:
Hello Harold:

If you refer to the following page on my website, approximately half way down the page you will see where I have listed a number of different release agents (or release oils) that can be used with success: hypertufa and concrete mold preparation tips.

There is also other good information on that page that just might be of use to you, too.

Hope this helps you. Good luck with all your garden art projects.

A Garden Art Enthusiast Wants To Build
A Mini-Stonehenge In Her Backyard

I received an email from Wendy who asked:

We want to make a small version of Stonehenge in our back yard rockery and cannot lift the large stones we would want.

Hypertufa is a perfect alternative, suggested by a friend. Any hints or tips would be appreciated. I’ve bookmarked your site and will return to it when I can digest all that is there. Thanks so much!

My reply:
Hi Wendy:
Thank you for contacting me and hypertufa would certainly be a great mixture to use for making large boulders and rocks!

I think just about everything you will need to know as far as recipes, proper mixing and curing, etc. can be found in all the hypertufa pages on my website. To easily see all of them listed in one place, you can go to the Site Map on my website, and scroll down until you find “Hypertufa How-Tos Overview”.

I encourage you to read through each page to gain a full understanding of everything, and to think about which recipe you want to use; do you want to add colorants, etc.

In order to accomplish tall, vertical boulders such as those found in Stonehenge, you are going to have to construct forms on which you’ll smear the hypertufa. To get really large rocks and such, you can’t make huge solid blobs of ‘tufa! Plus they’d weigh a lot, which is why you aren’t using real stones in the first place!

One possible way to make the forms could be accomplished by using wood and chicken wire stuffed with plastic (to help the chicken wire hold it’s shape). Since I have no idea how tall you want your version of Stonehenge to be you might have to make forms that are much sturdier than what wood and shicken wire can offer. Now you are moving into the realm of making armatures, which is a whole other ballgame!

No matter what type of frame or armature you end up making, think about the fact that the frames will become one forever with the ‘tufa. So you might be making a LOT of frames for this project, too!

This “Stonehenge” hypertufa rock project will require some artistic creativity and ability on your part, of course. I will make a shameless plug on my behalf: in my Hypertufa eBook, I do discuss form making in more depth than on my website, and I have some photos of how to make a form as I’ve just mentioned. If you are interested, you can find out more about my eBook, how to purchase it, and such here: www.HypertufaBooks.com.

I believe that if you do all your reading “homework” before you dive into this project, you’ll be good to go.

I would also highly suggest you experiment on a smaller object first, to get the hang of getting the recipe ratios correct, etc. Some people are successful from the get-go, and other folks have a couple of disasters before they get it down right. You be the judge of how to proceed. 

Good luck with this large-scale hypertufa rocks project!

~~~

Wendy emailed back and said:

Hi Claudia,

Thanks so much for the notes. My husband is very good at learning everything he can about something before he jumps in and I’ll be the #1 assistant, so we’ll be fine.

I do appreciate your suggestion of trying a small something first. We have a book filled with pictures of stone circles and other rock gatherings in Celtic Britain. I’ve been looking through it and I have to say that Stonehenge is my favorite, but that’s a LOT of work. We may adapt it to the space available.

I can just hear family and friends now, when they view it for the first time.

We’ll first check your website and go from there. I appreciate your link to the eBook.

Thanks again for everything!

Best regards,
Wendy

A New Hypertufa Project Enthusiast
Asks For Birdbath Basin Ideas

Annie emailed me and asked:

I have recently made some minature hypertufa birdbaths and now want to try a larger project. I LOVE the idea of using large leaves with a hypertufa recipe and wondered how to go about shaping the birdbath’ s bowl and other things like that. I think I can figure out the base, but I can’t figure out how to make the bottom of the bowl.

Any creative ideas you can share with me? Annie

—————-

My reply:
Hello Annie:

Sure, I’ve got a couple ideas. To start with, take a look at this photo!

How about using a very large leaf for the entire bowl?

Yes, you’d have to get your hands on a real leaf, such as a gunnera leaf which was used for the casting shown in the photo.

Gunnera leaves can get really huge. As you can imagine, they are highly desired for leaf casting projects.

Unless you know someone who will give/send you a leaf, maybe you live in a warmer cliimate and have the room to grow a gunnera plant. If you do, you’re lucky!

This photo shows an incredible concrete gunnera leaf made by the artist team of Little and Lewis. If you’re not familiar with their mind-bloggling garden art … please go and visit their website.

Or … if you can’t get your hands on a gunnera leaf, how about an elephant ear leaf?

No matter what size of leaf you end up using, if it is for making a birdbath basin, you will use a large mound of damp sand on which to lay your leaf so it will hold the shape you want in order to apply the wet (and heavy) hypertufa or concrete mixture. A bag of play sand (found at a store like Home Depot) is cheap and what many people use for leaf projects.

Lay down a piece of plastic larger than the size of the mound you will make (this helps the sand to retain the moisture); then dampen the sand so it will hold the height and shape mound you’d like; then shape your sand mound; and then lay the leaf down on the mound. Some folks will place another piece of platic on top of the damp sand before laying down their leaf. It’s up to you.

Make sure the leaf is spread out in the shape and height you want before you start applying the ‘tufa or concrete. By “height” I mean the higher you’ve mounded up the sand, the deeper the leaf basin will be to hold the water in your birdbath. Follow me here?

Also, make sure to carefully push and spread your wet mixture out to the edges of your leaf, and try to smooth off the edges, as it will be a lot easier to smooth off the edges when wet, rather than trying to do it after it is cured … though not impossible. And make sure you have enough of your mixture on the edges – don’t make it too thin or the edges could crack and break when it cures or after you move it off the sand mound.

For some helpful tips to help your project be a success, I encourage you to refer to my webpage Leaf Casting Super Tips.

Another idea … you could cast a smooth bowl by simply making a mound of sand; place a large sheet of plastic over it with as few wrinkles as possible in it (this will help the inside of your basin be “smooth”); mark off the circumference so you know you’ll end up with a perfectly “round” basin shape; and then apply your wet mixture onto the plastic surface.

For added embellishments and before your basin is totally cured, you could add partially cured little leaves all around the outside edge; or line the entire outside or inside of the bowl with the leaf decorations. You’d not want to give much curvature to the leaves, as you’d be laying them, in essence, on the basin. You’d attached with more ‘tufa or ‘crete and make sure to use bonding agent appropriately.

Since you’ve not said if you’re working in hypertufa or concrete, the only other idea would be to maybe stamp or carve in leaf decorations into very smooth ‘crete. I think this approach would be better suited for a concrete project.

I hope I’ve helped get your creative juices working! Good luck!

Sculpting Hypertufa Into Realistic Rocks
For Use In Bonsai Landscapes

Jim wrote and asked:

I am an avid bonsai gardener. How do I make hypertufa into rocks with sharp edges so they will look like small mountains and fit well into my bonsai gardens? Also what recipe would you suggest for these rocks? Jim

————–
My reply:
Hi Jim:
Thanks for asking your questions.

First, as far as sharp edges, that is what one would call “artistic expertise”. Meaning, you’ll have to use some kind of tool (maybe a small paring knife; a screwdriver tip; or an appropriate “professional” carving implement) to scrape and carve away the ‘tufa in order to get the crevices, sharp points and such you’ll need to make in order to reproduce the look of real rocks.

Next, about a good recipe – since I know this project is for use in your bonsai garden, I don’s see why a very simple hypertufa recipe that does NOT have perlite or vermiculite in it would work. After all, these are very small rocks, and because of that perlite or vermiculte would not give them a realistic look (at least not in my opinion).

So, you could use either of the recipes found on the following page, but you wouldn’t necessarily need to use the fortifiers: Hypertufa Sculpting Recipe.

And, for something as small as what you’re making, a “final layer” would not be necessary.

Really, any ‘tufa recipe can be carved, in essence. These recipes as you’ll note don’t have the perlite/vermiculite which allows a smoother surface. (The peat moss will give you enough texture.)

OH … I would highly suggest to really sift and/or pulverize the peat moss to a very very fine texture. Again, with such small objects as you’ll be crafting, you don’t want a huge chunk of peat in your recipe!

Hope this helps get you pointed in the right direction. Good luck with all your bonsai garden projects.

Is Hypertufa Waterproof?
Can It Be Exposed To Water 24/7?

Ken emailed and asked:

Is hypertufa a good choice for construction material for a waterfall? Is it waterproof enough to withstand the constant exposure to water?

Because of it’s easy use, I would like to build the spillways out of hypertufa. Please advise.

My reply:
Hello Ken:
Thank you for contacting me and I can tell you that hypertufa may not be the “best” choice for the spillways. I am not saying don’t use it, but be very aware that the peat moss in ‘tufa is meant to decompose, leaving the pits and crevices and tiny HOLES that is inherent in real Tufa rock.

So …. what if a hole or crevice ends up in not the best spot, and you have a leakage problem on-up-the-road? Think about that. Perhaps using a concrete recipe would do you better in the long run.

But! It doesn’t mean not to use it. I am just telling you of a potential issue to consider. I am aware of people using hypertufa for spillways, however I have NO knowledge of how long their project held up.

If your recipe is properly concocted, and you allow the spillways to cure properly before subjecting them to 24/7 water exposure, you should have no problems. But of course everything hinges upon your attention to details and level of expertise for a project like this.

You might also want to apply a good quality water-proofing sealant … again making sure everything has cured and dried properly before sealing and letting the water flow.

**And don’t forget about the alkalinity issues that can adversely affect (kill) pond fish and plants. Again … cure it properly. I have written an article that will give you more information on this issue: Hypertufa Curing tips for Ponds & Waterfalls.

Good luck!