I received an email from a sweet lady named P.J. asking me about how doable a “large” DIY hypertufa flagstone project might be and I think lots of you can benefit from her questions and my answers. So here goes:

Hi Claudia,

I love your website and blog and I have been reading all your info about hypertufa but I have a few questions. I want to make a patio in my yard and I would like to use the flagstone or slate mold. I am a widow and I will be doing this myself.

I guess my question is can I do it myself? I know the regular stones are too heavy for me to lift by myself and thought that the hypertufa stones would be lighter. I live down in Southern Florida where we do not usually get any freezing so I don’t think that I have to worry about the cracking of the stone. How long will they last with people walking over them?

Would your e-book on hypertufa address making the patio stones? I love the look of slate or flagstones and I will be doing the work myself. I am quite handy at repairing & fixing things so I know I could do it if it will not be too heavy.

Thank you,
P.J.

My reply:

Hi P.J.:
Thank you for contacting me and for the kind compliment about my site.

To answer your questions, yes I am sure you can tackle a project making hypertufa flagstones if you are at least a mildly active person.

There isn’t anything that is going to be horribly difficult in the process, but I guess the biggest thing to consider is the weight of the bags of Portland cement and sand you’ll be having to take out of your vehicle and transport to your working area.

The bags are normally between 40lbs – 80lbs. Can you wrestle 80lbs of dead weight?? (It’s not as easy for me as it used to be, I must admit.)

Next, though you won’t have the need to mix up huge batches at one time – as I am going to guess you’ll only have a few molds that can be used at a time – be aware that the mixing up and blending can put a strain on one’s back. Lots of crafters will mix up everything in a wheel barrow to keep from having to bend way down to mix up everything. Or many folks rent a small concrete mixer – it all depends upon how many flagstones you’re going to have to make, to determine if the cost of the mixer rental is worth it.

Yes, the ‘tufa stones will be lighter, and over time the peat moss will decompose leaving a more natural looking stone – that is unless you want super smooth stones (with minimal texture) like real slate. Then I’d use a pure concrete recipe. No peat moss (which means you can’t call the recipe a hypertufa recipe).

As I teach on my website (and in my eBook) … IF the recipe ratios are correct; IF the mixing and application method is correct; and IF you allow the object to cure properly, then you ought to have stones that will last almost indefinitely. But I always advise that you do some test runs – and I think especially so for this project. Make a small batch; record the exact ratios; the curing time, etc. If you have success (or failure) with your test run, then you know you are either good to go with your project … or if you’ve had a failure … then it’s back to the drawing board!

I caution you to NOT attempt this project without first getting a real hands-on feel of what working with concrete and such is like. It can be a temperamental animal … but not so bad because thousands of people are successful all the time once they get the hang of ingredient ratios and proper curing methods. After all, hypertufa making is NOT rocket science!

Yes … my Hypertufa How-To eBook does go into much more depth on the subject of hypertufa, however I can tell you that for the project you are wanting to do, you’ll find everything you need to know for free on my site. (How is that for being honest and not trying to sell you my eBook?)

Your main decision is what recipe to use. I would suggest one that includes a bonding agent which will help add more strength. I don’t suggest using reinforcing fibers in your recipe for a variety of reasons – mostly to make the project easier for you. However … even one of the basic hypertufa recipes most likely will do fine, too. But make a test batch first!

To review all the hypertufa pages on my site, you can easily see all the pages listed under the “Hypertufa” sub-heading on my website’s directory page. Check out the different recipes and projects – I do have one for flagstones – and I know you’ll find one that will fill the bill for you.

Oh … I had another crafter who wanted to tackle a “make homemade flagstones for the patio” project tell me she bought nice flagstone molds on eBay. I think the the cost was around $100, but a deal when you consider how much you’ll save in the long run if you DIY and of course because the molds are reusable.

Does this information help? I hope so. Keep me posted. Good luck with your hypertufa flagstone project!

Claudia

I received an email this week asking me:

A friend and I tried one of your basic hypertufa recipes without adding the fiber mesh. Our results are very crumbly. I think we goofed by not using it, right? Where does one find fiber mesh? NewLearner

—————
My reply:
Hi NewLearner:

I hate to say it, but I don’t believe the lack of fiber mesh in your basic recipe was the cause for a crumbly failure. Sounds like the amount of water you used and/or wrong proportions of ingredients was your problem.

You didn’t tell me the “basic” ingredients you used, nor the ratios. Too much or too little water is often the cause of failed hypertufa recipes. Sometimes too much of one of the dry ingredients can be the culprit. Since I wasn’t there to observe you mixing up the recipe, I can’t be more specific in figuring out the cause.

I suggest you (re)read this article: Hypertufa Recipe Mixing Guidelines.

About where to find the fiber mesh – you can check with commercial concrete companies if you cannot find it in retail stores that have a good assortment of concrete products. Fiber mesh can sometimes be hard to find in certain areas of the country. I also suggest you Google “fiber mesh for concrete” and many results will come up and you’ll find online sources.

Also read the blog post I wrote on just this subject: locating silica fume and poly fibers. I believe you’ll find it quite informative and helpful.

Remember … hypertufa “success” often takes a couple failed attempts. Really. Portland cement can be temperamental to work with. Most crafters really have to get the hang of the correct water ratio in relation to the portland cement, along with following proper curing methods. Keep trying your hand at small projects (less wasted materials) until you believe “you’ve GOT IT!”

I often get asked by many hypertufa and concrete garden art enthusiasts where to find “silica fume” and “poly fibers”, also referred to as “fiber mesh”. Depending where you live, it may or may not be very easy to lay your hands on this stuff.

PLEASE NOTE! Silica fume is sometimes confused with fumed silica (also known as colloidal silica and pyrogenic silica). These materials have different derivations, technical characteristics, and applications. Silica fume is very fine like beach sand and completely black.

Silica fume and poly fibers are used as strengtheners, normally referred to as fortifying agents. They help make your cured hypertufa or concrete object stronger. Often, you’ll want to use one or the other for items such as stepping stones or very thin spheres. I do have some recipes sitting on my website that I’ll refer you to, in case you aren’t familiar with recipes and/or projects that utilize silica fume or poly fibers. Here are three of them:

Hypertufa Recipe Using Fiber Mesh (Poly fibers)  (refer to last recipe on the page)
Hypertufa Sculpture Recipe
Concrete Recipe For Very Thin-walled Spheres

How to Locate Silica Fume and/or Poly Fibers

My first suggestion is to call commercial concrete supply companies in your area. Many times they will have either fortifier, and will be willing to sell you a couple of pounds. (You don’t need much of either one in a recipe – unless I guess you’re making something collosal in size! ).

I’ve even read of people walking away with some for free, after explaining to the sales people what they will be doing with the silica fume or poly fibers. Seems the sales people get a kick hearing that Portland cement is going to be mixed with peat moss and water to make an odd concoction called hypertufa!

My next suggestion is to do what else … that’s right, find suppliers who sell via their online store. In doing a Google search today, I found EpoxyUSA.com carries poly fibers for a very reasonable price on the Fillers-Thickeners webpage. Note – I have no affiliation nor experience ordering from them. Perhaps you should contact them first to check shipping charges, etc. before you order. But I’ll wager a guess they are legitimate and probably fine to deal with.

Finding silica fume online seems to be more of a daunting task. I did find this link to the SilicaFume.org webpage. If nothing else, call them and see where you can purchase a small quantity online.

So, there you have it. I hope I’ve helped you locate two ingredients that do help make a difference in strengthening concrete and hypertufa recipes.

I received an email from Debbie asking me:

In the instructions given for the Hypertufa Hollow Garden Sphere, one of the materials needed was a deflatable ball.

Can you advise me where I would get such a ball? What size does it come in and what type material is it made of? (Guess you can see I don’t have any young kids at home nor any grandchildren. )

Thanks for your help. Oh by the way, I love the project info you send. My neighbor and I have tried a lot of the projects you have sent to me in your great little Newsletter. Debbie

My reply:

Hi Debbie:
I’ll be happy to explain this for you. You can use a plastic blow-up (inflatable) beach ball like the kind you’d toss back and forth to each other while frolicking on the beach which you can buy at most drug stores, Wal-Mart, etc. Just depends upon the climate zone where you live as to whether you’ll be able to find them year-round. Stores don’t usually stock them during frigid winter months. Or of course I am sure you’ll find them on the internet. And they’re pretty cheap.

The main thing, though about using these balls for a hollow sphere mold (form) is that they can deflate S..L..O..W..L..Y and without it being noticeable in the beginning. Most normally this is due to a pin-sized hole that allows the air to escape. I know in my case, as a kid, sometimes I’d find that my new beach ball was pretty much totally deflated within about a day. This was probably caused by a tiny pinhole leak.

Now … add the weight of a heavy, wet ‘tufa or concrete recipe pressing down on the ball. The weight helps to accelerate the air escaping. Some crafters have reported that when they came back the next day to inspect their sphere to see how it was curing – yikes! They found a pretty sad looking deflated and slumped down sphere.

Now … perhaps this “disaster” might prove to be an interesting sculptural form that once cured can be painted and utilized in some other fashion, but let’s just say most folks end up having to trash the project. So … “cheap” beach balls are quite OK most of the time and hold air without causing a project failure … but just be aware of the potential deflation problem.

Or you can get one of the big heavy-rubber inflatable types that people use to exercise with. These can be found at Wal-Mart or Target in the exercise depts. (as examples) and just the other day I saw some at T.J. Maxx for sale. This size ball would of course be used if you want to make a really big garden sphere. But deflation problems from small leaks most likely won’t be an issue for you.

Now, there are other smaller, sturdier type balls you could use, but you asked about inflatable/deflatable, so I am mentioning the most often used balls. You want something with a stem you can blow into or can hook-up an air supply to for automatic inflation. And the stem allows you to deflate the ball easily after your sphere has cured enough.

Good luck with your hollow sphere project!

I received an email from Jan R. asking me:

Hi there, I want to make a hypertufa leaf or concrete leaf fountain. After the leaves are made how would I form the fountain and to what? Got any ideas? Thank you for your time.

Sincerely, Jan

My reply:

Hi Jan:
Thank you for contacting me about making a concrete or hypertufa leaf fountain, which is a fun project to do. The answer to your questions will be rather difficult ones to answer at this point, as you’ve not told me how the leaves are to catch and/or collect the water; how many levels you want; or what sort of base you want the fountain to set on, to name a few.

Make sure you read through the ins and outs of working with hypertufa and concrete for leaves. Here are a couple of articles on my website that will be of help: Leaf Casting with Hypertufa: Tips for Success, and Concrete Leaf Casting: Super Tips From the Pro’s.

There are many variables I’d have to know in order to walk you through this, but basically here is what I believe will help you think this project through:

• Most crafters make two or three leaves set in a tiered fashion, and at angles to each other, which allows the water to spill over the edge(s) and finally collect in the bottom leaf.
• Joining all the pieces can be accomplished by mixing up a fresh batch of your recipe with bonding agent included in it and some bonding agent also painted onto the areas of where everything will be joined for good measure. (You would have to wait until the leaves were cured enough to be handled before you start joining them.)
• You need to seal the concrete or hypertufa leaves with a water-proofing sealant.
• You need to know how to install a simple pump in order to get the water flowing back up to the top-most leaf; you also need to get a pump that has the right GPH rating to effectively keep the water flowing.
• Another consideration – WHERE are you going to hide the pump and cords? Inside the base, or …? I wouldn’t think you want the pump and connections visible.
• You will need a GFI electrical connection available to plug in the motor for the pump. **There’s no side-stepping this requirement – water + electricity do NOT mix!

To learn about GPH and GFI, read this article on my website. Skim about half-way down: Garden Spitters Installation: GPH & GFI Considerations.

This is as specific as I can be for you at this time as I’ve no clue as to what actual shape/form you want your fountain to have. Nor how large you foresee the thing to be. What kind of leaves do you plan on using? Huge gunneras or something medium sized?

But, I do hope these tips help get you to thinking and sketching your ideas out on paper. Though not the easiest project, it is quite doable. Obviously your creative skills will really come into play with a project like this!

Good luck. I really hope you are successful with this leaf fountain project … personally I think there’s nothing nicer than the sound of trickling water in my garden.

I received an email from Carole M. asking me:

Could hypertufa be used to create boulders to be used on a waterfall on a pool? We built one that needs help. Thanks!

My reply:

Hi Carole:
Thank you for contacting me and if you are referring to using a hypertufa recipe (or even a concrete recipe) to make boulders for your waterfall … yes you certainly can use the appropriate recipe for this project.

I suggest you read over ALL the pages of hypertufa and concrete information I have on both my website and my blog pertaining to hypertufa and/or concrete projects. There are things you need to be very aware of if your finished project will be in contact with plants or pond fish.

**Let me caution you that whether it’s a ‘tufa or concrete rock you are making, the thing you really must do as a final step before you allow plants or fish to come into contact with water that is in constant contact with your rocks or boulders, is to leach the lime residue out of the rocks/boulders (or even a trough or planter for that matter) completely.

This important step cannot be over-emphasized as necessary to do! Read more about that here: Build a Hypertufa Garden Pond Waterfall.

In addition, I will make a shameless plug on my own behalf, and recommend you purchase my Hypertufa eBook, as there is more in-depth information there that will be helpful to you. You can find information about my eBook here: HypertufaBooks.com. The eBook will more than pay for itself after you’ve made your first boulder, for sure!

A hypertufa or concrete boulder project will be quite an undertainking for you, so I will advise strongly that you do a small “test” project, or couple of projects, using the recipe you decide upon. Get the hang of working with the recipe; the curing time, etc.

Here is a blog post you will find informative since you’re new to working with recipe mixtures containing Portland cement: The Number #1 Cause For Most Hypertufa and Concrete Recipe Failures.

Best of luck in tackling your hypertufa boulder project!

I received an email from Lael asking me:

I have a terracotta strawberry jar that is flaking off on the surface. I want to cover it with hypertufa. I would use about 1/2″ to 1″ layer, and leave the jar in place. Do you think that would work? I love your site and have made several spheres and a planter.

My reply:

Hi Lael:
Yes – your idea of using hypertufa to resurface your jar would work, as long as you do a really thorough job of scraping off all loose flakes and clean off any dirt, etc.

Then I would suggest to wet down the jar, apply a good coat of bonding agent to the jar; add some bonding agent into your hypertufa mixture and then apply it. Click here to learn more about hypertufa bonding agents.

But … do you want the peat moss to decompose for little pits and crevices? Or would perhaps a “pure” concrete recipe be better for this project if you want a smooth surface (since I don’t know what final look you are trying to achieve)?

All going well hypertufa or concrete ought to stick onto the terra cotta forever.

Good luck!

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!!

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!

I received a question from a crafter who had read my post about using hypertufa to skim coat vertical walls. She has a metal shed that she’d like to use the technqiue on and wondered if it would work in her situation.

I told her I’d found and saved some information years ago about this very issue and would post it. So … here it is. Anyone who works with a hypertufa or concrete recipe and uses a metal mold, or has something else made from metal that will be embedded into the ‘tufa or ‘crete needs to be aware of this information.

Aluminum
Embedded aluminum roof flashing, aluminum water stops, aluminum electrical conduit, introduced aluminum powder (sometimes used to foam concrete), or embedded structural aluminum shapes may all corrode in concrete or mortar. In all cases, a reaction that forms aluminum hydroxide and hydrogen gas occurs, and may cause expansion and cracking of the concrete or mortar. The common use of calcium chloride (or other alkali compounds), and dampness of the concrete increases the reaction rate. Usually, coating the aluminum with bituminous paint, impregnated paper or felt, plastic, or an alkali-resistant coating will prevent or sharply reduce the corrosion.

Copper
Copper embedded in concrete and/or mortar is usually roof flashing. Embedded copper is practically immune to reaction with corrosive alkalis, even if exposed to constant moisture. Copper will not react with dry, hardened concrete and/or mortar. Rainwater leaching, however, may bring chlorides in contact with the metal. Corrosion may occur and result in a green discoloration or runoff. Consequently, chloride admixtures should not be used in concrete if contact with copper is expected.

Lead
Lead will always corrode when in contact with fresh concrete and/or mortar. The high pH from calcium hydroxide is the cause of the corrosion. Cured, seasoned concrete or mortar will not react with lead. Corrosion of embedded lead flashing in mortar joints will usually result in the production of a lead oxide, a white discoloration. A special case of lead corrosion, called differential aeration, occurs when a lead strip is partially embedded in concrete so that part of the strip is exposed to air. The embedded section has a different electrical potential than the section exposed to air. The result is that the strip will become polar in the presence of moisture. Gradual corrosion and disintegration of the embedded lead will then follow. In such a case, and in all other cases, the embedded portion should be coated with epoxy, varnish, asphalt, or pitch.

Zinc
Zinc is highly reactive with alkalies and will deteriorate to some degree upon contact with fresh concrete and/or mortar. The reaction is limited due to a corrosive film that forms on the outer layer of the zinc. It protects the underlying metal from further reaction. Zinc will not react with dry, seasoned concrete and/or mortar. Embedded zinc will react with moisture and calcium hydroxide to produce calcium zincate. Zinc corrosion may also occur when galvanized iron, in the form of flat or corrugated sheets and rebar, comes in contact with fresh concrete and/or mortar. Galvanized iron is coated with zinc, and will react with moisture and chlorides in the concrete and/or mortar to produce zinc chloride. The result is expansion and cracking of the concrete and/or mortar. The metal should be protected with epoxy, varnish, asphalt, or pitch.