Hypertufa How to Tips and Techniques

Hypertufa Tips and Techniques

What is Hypertufa?

Well, Hypertufa is an artificial stone used for making,

amongst other things, garden ornaments, pots and

troughs. It is made from various aggregates and bonded

together with Portland cement. It‘s used as a alternative

to natural tufa, which is a slowly precipitated limestone

rock.

A Hypertufa pot is very porous which makes it good for

plant growth. It is also fairly light in comparison to other

pots made from terra cotta or concrete and can cope

with low temperatures down to -30C.


Hypertufa Glossary

The following is a glossary of terms used when making Hypertufa. If you think

there is something missing from the list please add a comment below.

Accelerator – Ingredient added to increase the hydration and to shorten the set

and cure times.

Admix – See Admixture.

Admixture – Generic term for any non-bulk material added to Hypertufa. It is also

an abbreviation for acrylic bonding admixture, which increases strength while

reducing moisture absorption in Hypertufa.

Aggregate – Any dry bulk material added to Hypertufa other than Portland cement

and sand.

Air Entraining Agent – An ingredient that can be added to a Hypertufa mix

which captures miniature air bubbles during the mixing process. This reduces the

harmful effects of freeze-thaw cycles.

Alginate – A one time use mould making material used primarily for body casting.

Armature - A ―skeleton‖ or support structure for large Hypertufa projects.

Bug Holes – Small holes found in Hypertufa castings caused by air bubbles.

Casting – The end product of the moulding process.

Cement – See Portland cement.


Chicken Wire – A light galvanized wire fencing usually made with relatively large-

sized hexagonal mesh. Can be layered around an armature to hold the Hypertufa

mix in place and strengthen the structure.

Closed-Cell Foam – A hard, non-absorbent foam.

Compressive Strength – The ability of Hypertufa to to withstand a downward

force or to sustain a heavy weight.

Concrete – A mix of Portland cement, sand and water. The standard construction

recipe calls for one part Portland cement to three parts sand/shingle.

Concrete Admix – See Admixture.

Cure – The process by which Hypertufa hardens; dependent on sufficient hydration

and temperature.

DWT – Drywall tape.

Efflorescence – Salts which leach out of Hypertufa during the curing process.

Faux Bois – Imitation wood (French).

Form – Mould used for setting the outside shape.

Grot – An Abbreviation of grotesque, They look like gargoyles but instead of being

used as rain spouts they are used as planters.

Green – Uncured.

HWM – Hardware mesh, cloth. Used to reinforce larger Hypertufa projects.

Hydration – The chemical reaction between water and Portland cement.

Model - An original piece used to make a mould.


Mould – A rigid structure used to hold green Hypertufa into a fixed position until it

sets. See also positive mould, negative mould, mother mould.

Mortar – A variation of concrete used in masonry; it does not contain rough

aggregate.

Mother mould – Outer, often rough mould made of the back of a mould. Used to

secure the mould during the casting process when it is made of flexible or fragile

material.

Moulage – A reusable mould-making material that is used primarily for body

casting.

Negative Mould – The casting of a model which is made to create a positive

mould. Used when the original model is fragile and requires the use of non-durable

moulding material.

Nylon Fibres – Added to Hypertufa add strength and cohesion.

Perlite – Volcanic glass superheated to form a lightweight aggregate which can be

used in Hypertufa. Has a high moisture content.

Plasticizer – An ingredient that can be added to a Hypertufa mix to increase it‘s

workability.

Portland Cement – A powdery substance that is produced by burning a mixture

of clay and limestone at a high temperature. It is a primary ingredient in Hypertufa.

Positive Mould – A concave mould which prevents the escape of the moulding

material during the moulding process.

Rebar – Steel bars usually used in concrete to provide reinforcement. Can be used

to make an armature in Hypertufa projects.


Sand Casting – The process of manipulating sand to create a mould and then

filling the mould with Hypertufa.

Silicon Dioxide – Can be added to a Hypertufa mix to increase density and water

resistance via a chemical reaction.

Slurry – A paste made with Portland cement and water.

Set – The initial hardening of Hypertufa before it has fully cured.

Tufa – Naturally occurring soft or porous rock formed by water deposits. Hypertufa

is an artificial version of Tufa.


Hypertufa Recipes

There are quite a number of varying Hypertufa recipes you can make. The particular

Hypertufa recipe you use will depend on what result you are trying to achieve. A

basic Hypertufa recipe will generally contain varying amounts of peat, Portland

cement, perlite or vermiculite, sand and water.

The following is a good basic Hypertufa recipe:

1 part pre-mixed Portland cement/sand mix

1 part peat

1 part perlite or vermiculite

water (amount will vary depending on how dry the peat is)

You can vary the Hypertufa recipe depending on how heavy/strong you want your

creation to be or if you want to carve it. You can also add cement colorants to the

mix to give a more realistic rock color.

Below recipe is stronger than the basic hypertufa recipe I wrote about previously. It is

good for making hypertufa troughs as they need to be made quite strong.

The ingredients are:

2 Parts Portland Cement

3 Parts Sifted Peat Moss

3 Parts Perlite

Synthetic Concrete Reinforcing Fibres (about a hand full for a hypertufa

trough)

Water


Just a just a quick note to remind you that Portland cement is NOT concrete.

Portland cement is an ingredient of concrete. Be sure to pick up the correct sack,

they are heavy!

You should be able to get most of the ingredients in your local hardware store.

The reinforcing fibres might be a little more tricky to get hold of but they

should be available in your local masonry supply store.

Mix your ingredients well in a wheelbarrow before you add the water. When you add

the water, do it slowly so you don‘t make the mixture sloppy. You should be able to

grab a handful of the mixture and mould it into a ball and it should hold together. The

amount of water you need to add will depend on how dry the peat moss is to begin

with.


Make Hypertufa Pots

Human beings have been using stone for sinks and animal troughs since time

immemorial, hence there is a dearth of these commodities. The demand supply gap

has also made them very costly. ‗Hypertufa‘ is a cheaper alternative. It has all the

useful qualities of the Tufa rock and also has a much lesser weight than the normal

concrete. It never freezes. Peat moss, sand, perlite, Portland cement and chicken

wire are the simple ingredients needed for the construction of hypertufa pots.

The gear needed for actually making the hypertufa pots is pretty basic and consists

of heavy rubber gloves, respirator to avoid peat moss and cement dust, 4 mils thick

plastic sheet, tub, pot, a container for mixing, screwdriver, wooden dowel and wire

brush.

The process of constructing hypertufa pots consists of three steps. The first step

involves making a uniform and smooth mixture of peat moss, Portland cement and


sand, perlite or vermiculite in the proportion of 2:1:1. You can use a little water to wet

the mixture so that it is only slightly seen when pressed with your hand.

Selecting an appropriate mold constitutes the second step. One suggestion is a two

gallon black plastic pot.

The third and final step is to place an adequate mixture of concrete in the bottom of

the mold. It is advisable to keep the small pots 1-1.5 inches deep. Continue building

up the mixture till you achieve the desired level of thickness while simultaneously

smoothing the bottom and the sides and rounding off the edges. This will increase

the durability of the pot. When you reach the proper height, you need to fold the pot

with plastic from within. After this, you start with the process of curing by placing the

pot in a warm environment for the initial week and at 50F for the following two

weeks. The pot needs to be away from freezing point as water is needed to cure

concrete.

Spraying the pot with water regularly helps and it is compulsory for places with dry

weather. Once the curing process is complete, you can take the pot out from its mold

and take off the plastic. The pot is extremely fragile at this point and hence should be

handled very carefully.


Hypertufa Trough

I will explain in a step by step process how you can build a beautiful and practical

hypertufa trough for your garden or patio. Hypertufa troughs are very plant friendly

containers to use. This is due to there think porous walls which act as a reservoir

between watering and allow air to flow around the roots. Hypertufa troughs also have

a very natural appearance in the garden as they attract mosses and lichen.

To make a mould for our hypertufa trough we are going to use two cardboard

cartons, one smaller than the other to fit inside it. There needs to be a 5-6cm gap

around all the edges so that the walls of the trough will be thick enough. For larger

hypertufa troughs obviously you will need to increase the wall thickness.

Place the large cardboard carton on a piece of plastic sheet on flat ground. Place

concrete blocks or other similar heavy items around the edge of the carton. This will

stop the edges bowing out when the hypertufa mixture is added and the carton

becomes damp.

You now need to mix up some hypertufa. This is done most easily with a

wheelbarrow and a shovel. We‘ll be using the strong hypertufa recipe discussed in a

previous post. Measure out 3 gallons of sifted peat moss, 3 gallons of Perlite, 2

gallons of Portland cement and a handful of loosely packed reinforcing fibres into the

wheelbarrow and mix thoroughly with the shovel. If you want to mix the ingredients

by hand that‘s fine, but wear some tough rubber gloves.

You now want to add the water very gradually, so as not to make the mixture sloppy.

You should be able to grab a handful of the mixture into a ball and it should hold

together. The amount of water needed will depend on the dryness of the peat moss.


Take the hypertufa mixture and fill the large carton to a depth of 5-6cm. Push small

pieces of dowel or bamboo through the mixture to create drainage holes, these will

be removed later. Make sure the mixture is compacted by using the end of a piece of

timber to tap it down, especially in the corners and around the drainage holes.

Now place the smaller carton inside the larger one, making sure the gap is even

around all the edges. Place a small amount of sand in the smaller carton to stop it

from floating up and to support the sides. You will need to gradually fill up the inner

carton with sand as you build up the walls of the hypertufa trough.

Build up the walls of the hypertufa trough gradually, making sure to compact the

mixture as you go with the end of the timber. When the walls are at the desired

height leave the trough for 24 hours.

When you come back to your hypertufa trough the next day, you should carefully

remove the sand from the inner carton and the wet cardboard from the sides, inside

and out. Don‘t worry about the bottom at this stage and don‘t try to move it as you‘ll

lose your hypertufa trough.

Take a wire brush a rough up the sides and edges to give your hypertufa trough a

more natural look. You can also score designs into the sides at this stage but be

careful not to damage the trough as it will be quite fragile.

Now leave for a further week to cure and there you have it, a hypertufa trough for

you garden or patio.


Make a Hypertufa Trough

To make a hypertufa trough, you'll need peat moss, perlite, and Portland cement.

Make sure you buy straight Portland cement. You don't want any of the pre-mixed

concrete or mortar you'll find on the market.

You'll also need a few ounces of synthetic concrete reinforcing fibers, which

strengthen the planters. You can find the fibers at most masonry-supply stores or

online.

For mixing the ingredients you'll need a wheelbarrow or any large plastic container.

You'll need a sieve or screen to sift the peat moss to remove sticks and lumps. And

you'll need a stiff wire brush to remove rough edges. Wear rubber gloves while

mixing and handling the mixture because Portland cement will irritate your skin. A

small dust mask helps keep perlite dust from irritating your nose and lungs.

This project can be a bit messy, so pick your work area with that in mind. Part of

making a planter is letting it cure for 12 to 24 hours until the cement and other

ingredients harden. Bright, hot sun can cause uneven curing, and might make the

planter crack or fracture, so pick a shady spot to make your planters.

You'll want a sturdy, flat surface. I like working at a picnic table. I cover the table with

heavy plastic sheeting, which I tape to keep it from sliding around.

Finding the best mold for the job

A planter's shape is limited only by your ingenuity and whatever potential molds you

have on hand. Don't use wooden or metal molds unless you first line them with

plastic, otherwise the mixture will stick to the molds and you will damage the planters

when you try to remove them. The mix won't stick to cardboard, plastic, or Styrofoam

molds.


To make a rectangular planter, I use two nesting cardboard cartons as molds. The

larger box functions as the outside form and the smaller box is placed inside. This

creates a space of 1 in. to 2 in. between the two boxes into which the mixture can be

packed and tamped down. A larger trough will require thicker walls to maintain

strength and, therefore, more space between the two boxes.

Molds can also be made from the polystyrene foam used for house insulation. The

pieces are held together with wooden cooking skewers. You can get this kind of

foam at building-supply stores.

For a more free-form look, you can press the mixture over a plastic-bag-draped

earthenware or wooden plant container. Another alternative is to make a mound of

soil or sand and then cover the mound with a plastic bag.

Proportions for a proper mix

Measurements for the ingredients are not exact. Rough proportions are helpful, but

ultimately you will develop a feel for how wet the mix should be. What you're after is

a mixture that's about the consistency of cottage cheese.

Here are the rough proportions for the mix by volume: two parts Portland cement,

three parts sifted peat, three parts perlite. You'll need much less of the reinforcing

fibers, about a handful.

Here's another way of looking at it. To make an 18 x 12 x 9-in. planter, you need

approximately 2 gallons of sifted peat, 2 gallons of perlite, 1-1/3 gallons of Portland

cement (about 12 lb.), 1 cup of loosely packed reinforcing fibers, and water.

Measure the peat moss, perlite, Portland cement, and reinforcing fibers into a wheel

barrow or other large container. Using gloved hands, mix the dry ingredients.

Add water slowly, mixing with your hands until the material is the desired

consistency. Grab a handful of the mixture, and squeeze it; it should hold together

and only a few drops of water should emerge. The total amount of water needed will

depend on the dryness of the peat moss and the humidity in the air. The mixture


shouldn't be runny -- too much water and you'll get a weak container. A free-form

container needs a drier mixture so that it will hold its shape.

Just like making mud pies

Every time I make another one of these planters, I feel like a child making mud pies.

It's fun!

When I use the two-box method, I put a 1-in. to 2-in. layer of the mix on the bottom of

the larger box. Then I center the smaller box inside the larger and pack the mix firmly

between the sides of the two boxes. When the sides reach the desired height, I

smooth and level the top edge.

If I'm molding a planter over an overturned flower pot or a mound of soil, I begin by packing

a 1-in. to 2-in. thick layer of the mix around the bottom of my mold. Then I work upward,

adding more material until I reach the top. I pat the mixture smooth and keep the top as flat

and even as possible. This will be the bottom of the pot when it is turned over.

Planters require two stages of curing

Curing refers to the drying of the material and to the chemical bonding that takes

place. Curing has two stages: an early stage when the planter should not be moved,

and a longer drying period following removal of the mold. The initial curing period

takes 14 to 36 hours, while the latter takes about three weeks.

For the first 36 hours, cover your planter with plastic. The plastic makes it cure more

slowly, and slower curing produces a strong planter.

After a day and a half, I test the hardness of the mixture with my fingernail. If I can

scratch the surface, the mixture is still too soft and should be left for a few more

hours and then retested. When it requires a screwdriver to scratch the surface, the

planter is ready for the second stage of curing.


I carefully remove the mold from the planter, and then smooth the corners and rough

edges with a stiff wire brush. You can texturize the planter by scoring it with the

brush. Be careful not to press too hard, as the walls are still friable. Leave the planter

in a shady spot for about three weeks to finish curing.

After three weeks, the planter will be a lighter color and will weigh less. The last step

is to leach out the strong alkali or free lime contained in the Portland cement. A

heavy concentration of lime is harmful to plants. I leach away the lime by filling the

porous planter with water. Over the next ten days, I refill the planter whenever it's

empty. If you live where it rains a lot, nature will do the leaching for you. I like to

make planters during the winter and leave them to leach until spring.

Finishing touches

The planters are naturally porous, but if you want additional drainage, drill a hole in

the bottom using a masonry bit.

I've made dozens of these planters, and have used them for herbs—thyme, chives,

sage, chervil, and mounding basil—and vegetables, too. Round carrots, baby beets,

radishes, tiny Mei Qing Choi, and alpine strawberries adapt beautifully to these pots.


Make a Hypertufa Ball

Start simple. Start by making a stepping stone or just a hypertufa ball. Do not start

with a complicated project until you are proficient with hypertufa and comfortable

using it.

Use this simple hypertufa recipe. There are many others, and you can experiment as

you become more proficient, but this is a good recipe to start with. Mix 3 1/5 gallons

of Portland cement (do not use Quickcrete), 2 gallons of sand and 1 1/2 gallons of

peat moss.

Wear rubber gloves. Wearing a respiratory mask is a good idea because Portland

cement is a fine material and easily inhaled. Break up the peat, removing all large

twigs and other pieces of material. Mix it until you cannot see peat or sand. You can


store this basic mix and wet it as you need it. It stores well, but will harden if exposed

to humidity.

Use a peat moss sieve to sift the peat moss. That makes it easier to clean it. Most

other tools you will probably already have and will find them in the house as you

need them.

Put some dry mix in a bucket, and wet it just a little at a time, mixing well after each

water addition. You must wear disposable gloves to work with this. Do not get the

mixture too wet. Always reserve some dry mix in case you have to add some for

more firmness and for patching the finished product, if necessary. Mix the hpyertufa

until it holds its shape fairly well when a ball of it is squeezed in your hand.

Make a ball. To make a hypertufa ball, you can use an old tennis ball. Cut the tennis

ball in half and smear some petroleum jelly inside the ball, covering the entire inside

surface. That will make the ball come off more easily when the hypertufa dries. Fill

the mold by putting handfuls of mix in it and gently patting. Fill both halves of the

tennis ball. Be sure you fill them completely. Work it in until you are sure there are no

air spaces. Just keep filling the ball halves and patting in the material.

Put the two halves of the ball together and press them together firmly. Any excess

will squeeze out and fall off. Put your ball on top of damp sand, and let it cure for at

least 36 hours.

Carefully remove the two halves of the tennis ball. You now have a hypertufa ball. If

you wish, you can use some wet mix to clean up the ball where you find

imperfections and wipe it off with a rag as if you were sanding it.

As you become more comfortable with hypertufa, move on to more and more

complicated projects.


Make Your Own Hypertufa Container

Containers made from hypertufa are wonderful for displaying rock-garden plants or

succulents. Over time, the hypertufa ages gracefully, collecting a patina of mosses

and lichens. In this article you will find the recipe and instructions for making

hypertufa.

The process I use to mold containers is much simpler that the usual box-in-box

method that sandwiches hypertufa and some metal mesh in a frame. Instead, I

simply pack hypertufa around an overturned plastic pot or planter. And because it's

so easy to work with, hypertufa can be molded into many sizes and shapes.

Supplies

• mixing tub

• container for measuring

• peat moss

• perlite

• Portland cement

• concrete reinforcing fibers

• dust mask

• rubber gloves

• trowel

• plastic drop cloth

• plastic container for a mold

• wire brush

The recipe

1 part Portland cement

1 1/2 parts sphagnum peat moss

1 1/2 parts perlite


To add strength, I add a small handful of fibermesh, a synthetic concrete reinforcing

fiber, to each batch, which is easier to work with than sheets of wire mesh embedded

in the hypertufa. You can find fibermesh at masonry-supply stores or online.

Easy Steps

Measure and mix the peat moss, perlite, cement, and a small handful of reinforcing

fibers in your tub. You‘ll kick up plenty of dust at this stage, so be sure to wear your

dust mask.

Add the water while stirring with your trowel. Test the consistency frequently, as it‘s

much easier to add water than it is to readjust the dry ingredients. When a squeezed

handful retains its shape and doesn‘t release more than a few drops of water, the

mix is ready.

Mold the mixture around the chosen object, which has been placed upside down on

the plastic drop cloth. Avoid objects with a pronounced lip since it would make the

object difficult to remove from the finished container.

Pack the mixture up around the sides of the object, tamping it down firmly to bond

the hypertufa to itself and to avoid a crumbly texture. A 1- to 2-inch layer on all sides

will create strong walls.

Flatten the intended bottom of the completely covered object for stability, and shape

the sides to a desired form. Then poke your finger through the bottom to create a

drainage hole.


Wrap the container in the plastic sheeting, and place it in a shady spot for about a

day to let it harden.

Remove the wrapping after the hypertufa has had a day to harden. The mixture will

be firm but still soft enough to work with. Turn the container over, and remove the

mold.

Brush the sharp edges and the smooth top, if desired, to give a rougher, more

natural look to the container.


Rewrap your container, and place it in a shady place for another two days. Then

unwrap it, and soak it with a hose periodically over the period of a few weeks to

leach out the residual lime from the cement, which would harm plants.

TIPS:

To dress up your container, place evergreen sprigs or thick leaves around the rim of

the mold before you start building the sides of your container. Lift them gently from

the rim when you remove the mold.


Another recommended ebook for hypertufa and gardening:

Hypertufa-books

The Hypertufa How To Manual by Claudia Brownlie.

Hydroponic123

Complete Hydroponic Gardening Guide, Will Take The Beginner Or Advanced Gardener Through All

Of The Steps To Growing The Perfect Hydroponic Garden. From Setting Up A Beginner Garden To

Making Your Fertilizer, Or Troubleshooting Your Plants Growth.

Bonsai Gardening Secret

Discover Over 95 Pages Of Insider Secrets To Creating Stunning Bonsai Trees.

Orchid Care Experts

Orchid Care Using Easy To Follow, Step-By-Step Techniques

http://tinyurl.com/hypertufa-books

http://tinyurl.com/gardenstips

http://tinyurl.com/BonsaiGardeningSecret

http://tinyurl.com/OrchidCareExperts

Hypertufa How to Tips and Techniques

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