The-Artistic-Garden's Blog

D-I-Y Hypertufa Flagstone Project Questions

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

A Frustrated Hypertufa Trough Maker Seeks Helpful Advice

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!”

Sometimes These 2 Ingredients are Hard to Get Your Hands On

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.

Please Explain Deflatable Balls for Making
Hypertufa or Concrete Hollow Garden Spheres

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!