The-Artistic-Garden's Blog

More About Marjin’s Use Of Hypertufa Rocks
for His Alpine Garden Installation

A couple of days ago I posted about one awe inspiring use of hypertufa for a garden wall and house and alert blog reader Nancy did some nosing around on the internet (thanks, Nancy!) and found a link to the crafter’s website www.v-d-brink.eu and there happens to be a video posted there of the actual installation.

I thought posting that video would be of interest to lots of people, so here it is. If you’ve ever wondered just how much you can get addicted to working with ‘tufa … well I guess Marjin’s backyard installation kind of answers that!!

If You’ve Wondered How Durable Hypertufa Really Is …
Take A Look At These Photos

While doing some research the other day that had nothing to do with hypertufa, I came across a search result that caught my attention, clicked on it and started to scan everything that was posted there.

The photos and comments centered around a conference that took place in Holland. About a third of the way down the long thread – Wowee! What I saw made me immediately think that I just had to share it with the rest of you. I’ll bet none of you have ever seen anything like this before – a house built from hypertufa! The most incredible thing to me is that evidently the owner built everything you see in these two photos from hypertufa.

Come on! Talk about a massive project to tackle! This gentleman was obviously dedicated to transforming his property into one incredible natural looking Alpine setting.

Here’s a snippet from the actual thread: Wednesday, April 20, 2005 – 8:45 pm / Poster: Paul Cumbleton “… the remarkable garden of Marijn van den Brink. He built this – and his house – himself over 4 years. Almost all the “stone” you see is actually hand-made hypertufa – including the large slabs over 2m tall!!”

This forum thread also has some wonderful photos of massive arrays of Dutch tulips, daffodils and other flowers, and also many photos of Alpine gardening ideas that I am sure a lot of you could adapt to use in your gardens, if for nothing else than to make an attractive rock garden in a spot in your yard that might need a little something interesting added for visual appeal.

So … if you question the durability of building something simple like a trough or making a garden stepping stone from a hypertufa recipe, perhaps these photos will prove to you that at least one person in the world believes 100% that hypertufa can stand the test of time!

As long as you’ve gotten the recipe ratios correct and you’ve properly cured the hypertufa then ‘tufa can last almost indefinitely. I must emphasize this, as a bad batch of hypertufa can start out looking like it’ll be OK, and then it can start to fall apart.

To view the entire thread, please go to: Dutch International Conference of Alpine Plants 2005

I hope you find the information on the hypertufa house and other creative ways to do rock gardening as interesting as I did. Enjoy!

Avoiding Project Mishaps When Adding Water
To Your Dry Hypertufa Ingredients

Without a doubt, the amount of water mixed in with the dry hypertufa recipe’s ingredients is the most critical and determining factor of success or failure! Let’s call it your “make it or break it” ingredient. Why do I say this, you ask? Well …

Nearly every crafter who is new to working with hypertufa adds in too much water. (This mistake also applies to newbies who are trying to mix up a concrete recipe.) Too much water makes a recipe mixture that slumps badly. In other words, slumping means that your wet hypertufa just sort of slips off the sides of whatever you are applying it to. And there it is, sitting in a very wet blob on your work surface.

Even just an itty-bitty too much water can cause problems. Though you may think you’re doing quite well because you are able to keep the ‘tufa clinging to the vertical sides of your mold, just a hair too much water most likely will guarantee that you’ll end up with “weak” hypertufa. Weak meaning though it may appear to be curing properly, it might crack or crumble when you go to unmold it. Or it might survive the unmolding, but may fall apart during the hardening (curing) phase. Or it might make it through all of the cure … and then fall apart on you soon thereafter.

Yes … working with anything containing Portland cement can be tricky. Even professionals who pour concrete driveways and sidewalks (as examples) can have sloppy disasters on their hands if the ratio of water gets goofed up. So … how do you get the hang of how much water is or isn’t just right for a successful batch of hypertufa? I’ll tell you …

But first – as I ALWAYS encourage everyone who is new to working with hypertufa or concrete recipes – PLEASE do yourself a favor a try your hand at a small project. In this way if you do have a disaster, you’ll not have wasted a lot of ingredients. As a matter of fact, I have a beginner’s recipe on my website, which can help save you a little money if you want to give hypertufa a try and see if it’s something you really enjoy working with: Hypertufa Recipe For The Beginner.

Back to learning about the water ratio … understand that the consistency of wet mix you want SHOULD NOT look like the concrete you see being poured for sidewalks, driveways, patios and the like. No … what you want is more of a peanut butter consistency. A wet mix that you can hold in your hands and form a nice ball with, and when you give it a squeeze just a DROP (or two) of water will drip from it.

The magic trick to estimating the right amount of water for success is to add in the water in VERY small increments, and then stir, stir, stir! Wait a moment and if it appears dry and crumbly, add in a LITTLE bit more. Then stir, stir, stir again. Err on the side of your mix looking just a bit dry versus it appearing to look “just right”.

Walk away from your wet mixture at this point for about 10 minutes. Really! You know why? Within 10 minutes the recipe is going to go through a slight chemical change and the water is being absorbed even more by the dry ingredients.

After 10 minutes come back. How’s the batch of ‘tufa look? Can you make a ball of hypertufa in your hand as I explained before? If your mix is just a bit dry … then add only a tiny bit more water. Maybe a tablespoon or so and stir, stir, stir. Your mix should be ready to be applied at this point.

This is about all I can teach you about the right amount of water for a hypertufa recipe. (Sorry I can’t be standing right there next to you to demonstrate!  ) As the saying goes “Practice WILL make perfect”!

But what I and almost every other person who has worked with hypertufa have found, is that it is amazing that you can be mixing and carefully and slowly adding the water, and you’ve almost got it just right and then you think, “Hey! I’ll add just another little splash of water”, and … it’s a splash too much! Perhaps only one tablespoon was all that was really needed.

The result from that extra splash? Hypertufa that begins slipping, sliding and slumping down the sides of your mold.

I’m not trying to scare you away from trying your hand at making something with hypertufa. Not at all! What I’m trying to do is alert you to what is the #1 biggest mistake most every crafter makes in the beginning. Disaster can strike even after we’ve had many successful projects, normally because we get a little lax in paying attention to the careful addition of water.

So again, let me stress, though many crafters are successful in their very first attempt of working with ‘tufa and end up with a nice large trough or planter, I can only encourage you to start small. Get the hang of working with hypertufa recipes and then graduate to larger projects.

Good luck!

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!

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.

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!

How Important Is Peat Moss In A Hypertufa Recipe?
Is It OK to Substitute Another Kind Of Moss??

I received an email in late winter from Becky asking:

Claudia, Thank you so much for writing the Hypertufa How-To eBook as you did an outstanding job! So much info to pour over. It is a great resource guide for newbies like me.

I can’t wait to get started! But my problem is that I’m having trouble finding “PEAT” moss. I have found Reindeer moss, sheet moss, Spanish and Wood moss. Will any of these mosses work?

Is one type of moss better for a hypertufa recipe than another? Thanks for your time, Becky

My reply:
Hi Becky:
First, THANK YOU so much for the kind compliments. I tried my best to “over deliver” the information in my Hypertufa eBook.

About peat moss … I looked at your eBook purchase receipt and see you live in Ohio. Well…you should have NO problem finding PEAT moss (no … it is not the same as any of the mosses you listed). To be more specific, you want to look for “sphagnum peat moss”.

It is pretty darn easy to find, too. You’ll be able to find peat moss at any Lowe’s or Home Depot, or any gardening center that sells packaged soils. It is around $4 or $5 (cheap) to buy a very large package of it. (I suggest you go and look where all the packaged soils are kept in the outside garden depts. of the stores i mentioned. You’ll find peat moss, not to worry!)

The kind you want to buy is compressed into a rectangular “bale” and wrapped in plastic like this photo:

I don’t know the brand name off-hand that Lowe’s or H-Depot sells, but the point I’m making here with this photo is go and look for a very large squared/rectangular shaped compressed bale.

I know I can buy it right now at either store, but I am here in Tennessee and maybe because you are in Ohio and it is still super cold up there, they might not have it stocked yet. But they will … gardeners use it all the time to amend their garden soils with.

This should be the answer you were looking for.   

And welcome to making garden art with homemade hypertufa recipes! Have fun with all your ‘tufa projects!