Alternatives with Natural Fiber Reinforced Concrete (NFRC) (Update 2-29-12)

  Forming Rectangular NFRC can be a challenge. Plastic roof sheeting is strong in one direction because of its corrugated shape. Use it as a form for your island segments. They come in 8-foot lengths, ask the clerk at the hardware store if he/she can cut it in half for you. That makes a form 2-foot x 4-foot. Youll want the smooth plastic, so your -inch of NFRC wont stick to it. They also have fiberglass which has a rough surface. You dont want that, because it may be difficult to remove your NFRC.

These pieces are smaller, but just the right size for your float sacks. Also, your Island segments will be rectangular rather than hexagonal. They should follow the wave action better. And dont forget to place rope holes in each corner. And make the edges thicker for strength. You can place 2x4s as with the Hex style, but the corrugations and extra thick edges should do it for you. Try it and see.

Take some 8-inch plastic string, put a knot in the middle, and bury the knot in the wet NFRC. Place it the width of your plastic float trash bags, off center on your corrugated form and cover the knot with NFRC. So your float will wind-up in the middle of your island segment.

When the NFRC is cured (hardened,) place a round river stone in your float sack corner, and tie that string tightly just above the rock, cinching the sack securely so it wont float away from your finished island segment.

You can put strings near the corners, for bottle floats if you wish. Or, partially fill your float sack with air so the segment will float when you first put it in the water. Then fill it most of the way later.

These are much smaller, quicker to build, and easier to handle than the hexes. It will depend on the water conditions at your chosen location as to which one is best.

Sandy Surface

If you wish to have a sandy surface. Drill two small holes for the float strings and NFRC under the knot in the middle. Then coat the form with NFRC, and coat the NFRC by sprinkling a coating of sand on them. Note that you are making these right-side-up, and the string now goes on the bottom. With the corrugations, you should not need little stiffening walls. But when its complete you may wish to spread more sand like on a beach on top of the segments to cover over the corrugations.


Covered larger openings can be included, and even the door can be make of NFRC. Even large Holds like you find aboard ship can be made, however, think about how they are to react when in the water, both full and empty. There are plastic items at many stores to make forms for all kinds of things.


Writing at least the date and serial number, if you produce more than one on that date, will be more important in a couple of years, as you see how it functions.

Theoretically, it takes a month before the NFRC reaches full strength, but it is usable after a week. But how it functions after that depends on its environment, and how you use it.

You may wish to write comments in a notebook. Careful, you dont lose it. And reference the date and serial number of each piece, because they will be different, and memories fade after a couple of years.

Get a plastic chair, or two if your mate is with you, and set it by the Hexes youve built on the beach. Then sit down after each one, have a beer, and visualize how your finish island is to be, and how your next Hex is to be built to contribute to that.

Now, you may build Hexes up-side-down. That means that you may have to read what youve written from underwater. Unless you write the date backwards in the sand before you build it. That may prove impractical, so place a plastic tray, up-side-down in the sand and cover it with your NFRC, then youll have a flat place to stencil and paint the date, (or use an indelible marker, like they use on laundry,) that you can read from the top, and the slight depression can be covered with sand.

Make sure you always put it in the same place on each Hex, so you can find it a couple years from now, by just sweeping away a little sand. When the Hex is complete, and turned right-side-up, dont forget to paint the date on it.

You may find that it bends too much, or even breaks, so write down your comments for future references. You may have to make changes in a completed Hex. Dont forget to use bonding chemicals to make any new NFRC stick to any cured NFRC.


You may wish to make the island segments different, depending on where they are to go on your island. For example, you may wish to grow trees on some of them. Then get a plastic dish pan or garbage pail to add to your form. Measure where it is to go, and place it up-side-down and cover it with NFRC. Then when the Hex is complete, and put in the water, you will have a place to put your trees or whatever. And more flotation may be needed.

In some cases, especially if you plan to live on saltwater, you can leave holes for the roots to find, and hold up your Mangrove Trees or Coconut Trees without them falling over.

For freshwater plants, you may wish to imbed a watering hose. They sell plastic ones real cheap at your local hardware store you can lay in place before the NFRC is laid. Remember that the Hex is being built up-side-down, so measure appropriately, especially the connections between Hexes.

The Drip System has proven practical, and you may wish to water your plants that way. Your local hardware store should have all the needed components.

The interior of your dome can have struts, and bags of potting soil, or compost from your composting toilet to grow vines, so the vines will grow up the dome struts, and if possible the leaves can find a hole for growing outside. The fruit, even watermelon can hang from these vines, Ive seen it work on Saipan Island in the Pacific.

If that wont get you into the Mother Earth New, I dont know what will.

Tie Anchors

Another thing you may wish to imbed is anchors or holes for tie ropes for your dome home which will be attached later, and ties for your harbor, for tying up your boat. You may have to weld or bolt some rebar to the ties to spread out the forces in your NFRC, and/or make it thicker in those places. Include bolts or bolt holes if needed.

You may wish to put recycled tires around your harbor, so ties may be required to fasten the tires to your island. Or make Brians style floats using old tires for the edges of your harbor.

You may wish to make the Hexes of different sizes, so build the intermediate ones to match the tie holes at the corners. Dont forget the extra hole when needed.


You may wish to use different style floats on different places on your island, so include these in the NFRC. If your round river stone is of a reasonably standard size, you can just put in the little walls, and slide the plastic floats with their stones (as shown before,) in place later. Or include plastic ropes or strings to hold your floats with a round river stone in place in a storm, so they dont float away.

If you have to add flotation, just tie plastic bags of air to keep them from floating away, and put rocks near the openings to keep them up-side-down in the water. That will help keep the air in under storm circumstances. You may drop a round river stone in each bag, so you can tie the upper end outside of the bag with a plastic string, so It wont come off, and then tie it to your island where you can.


You may wish to add top coatings after your island is complete. You can fill holes, color code components, or make the NFRC stronger, by mixing a little Berylex, (see my previous articles,) to make the new NFRC stick to the old NFRC. And add the surface features you desire even after island construction.


You may also wish to have LED safety lights, both for boats to see your island at night, and safety to light up walkways and mark island edges for yourself. In theory you can just burry the wires in the NFRC, but then you cant change them. That may be ok, but you may wish to run conduit for the wires. If you intend to run 110 volt lines the conduit should be metal or made for water protection. But if they are to be low voltage LEDs and the like, you can use plastic.

Leave enough wire hanging out the ends to hook whatever to them. And include electric boxes where appropriate. Think about where the water will be when the Hex is finished, and place the wiring appropriately. Dont set it up so you or your loved ones get electrocuted! Thats why low voltage DC is a good idea.

The nice thing about building up-side-down on the beach is that you can dig a hole in the sand for placing things above deck level on a Hex, and then fill it up when its not needed. Electric boxes are a good example.

You dont usually need a licensed electrician on a floating island, but it may be a good idea. Or at least, read the instructions, so you can do it right.


Rishi probably didnt expect a storm to pick up his island and slam it onto the beach. That may happen to your island, so prepare your islands anchors appropriately. And your ties may have to be made in thicker NFRC to hold your island in place.

Water can be very strong. So you may have to wrap a whole Hex, or even your whole island in strong rope to anchor it sufficiently to hold things in place during a storm. Be sure and make the anchor ropes long enough to allow your island to move up and down with the tide, and/or storm serge.


Think about what is expected to be placed above each Hex and where, then include holes where needed. For example, if you need to get water from down below to load a still, or exhaust brine from your still, youll need to run pipes. And youll need holes in the NFRC to do that. Its better to make the holes than have to drill them later. Especially if you expect to use and electric jackhammer, while your Hexes are in the water. No, no!

Topside items such as ponds, landscaping, and windows to see the fish, all have to be planed and built into your Hexes. It can all be done right, if you think about it, and build them into your Hexes as needed.

Remember that Portland Cement will stick to glass (hard,) so you must clean the clear area in any windows before the NFRC sets.

How about a Hot Tub? Most places have plenty of sunshine, and the smooth surface that can be created in NFRC using plastic drop cloths can make a nice hot tub. With Berylex, you can make the pieces flat, and then assemble them later, with or without insulation, for insertion into a Hex, or to set on top of it. Dont forget to form a place to hold your beer! Maybe you dont drink beer, root beer maybe.

Maybe youd like a waterfall. NFRC can work well to hold rocks and things for the water to fall over, and a windmill to make some water flow. Remember that all such things may require extra flotation, which can be added by simply putting an extra Hefty Garbage sack full of air under the Hex, and tying it with plastic string so it doesnt float away.

Solar Power

Solar collectors can be made of NFRC also, just use a clear plastic cover imbedded in the NFRC, and place the whole thing directly in the sun. There are plenty of things on the Internet to show you how they are made.

A solar water heater would be real nice to heat your hot tub.

Wave Power

You may wish to use the relentless power of wave action, as Ive described in my other articles. The types of Island Segments you construct, and the fixtures required have to be planned for. One nice thing about doing standardized Hexes as island segments is that you can make changes and add features to your island later on. And most underwater things will not span more than one Hex, making connections difficult. Or, things that do, such a piping and conduit, have fixtures to make that easy.

However, if you need to have the deck follow wave action, then you need rectangular island segments, not Hexes.

Wind Power

The tower for your windmill needs to be anchored. So include these in the NFRC of those pieces. At least leave holes for future anchors. Rope size, not so big that you may trip in them.


In theory, furniture can be built into your Hexes. However, it may be much easier to form the flat pieces separately and put them together after the NFRC hardens.

Or, it may be more practical to just buy plastic commercial ones. However, you may wish to provide plastic string tie downs, so they dont blow away in a wind storm. In that case, coil a piece of string under a small piece of plastic drop cloth, or burry in the sand, and burry a knot in the NFRC to hold it there. Then when its up-right you can tie it to your furniture.

Underwater Work

Portland Cement will cure underwater. However, it depends on what kind of water, how its formed, and how its mixed. The Portland Cement Association can help, but its best to just try it. Or make the piece you wish above the water and then submerge it afterwards, like making a launch boat for traveling to land. It may prove much cheaper to use NFRC than to purchase one.

Above the Water

Many things can be built for use topside. Cabinets, chairs, tables, even toilets and showers can be made of NFRC and colored too. Use your imagination.

Once I built a shower/toilet combination. It would have been a lot easier if I had used NFRC instead of epoxy.


Dont pollute your water. You may eat fish from there. Instead, use and/or make of NFRC, a composting toilet. (See the Mother Earth News to find out how.) Then youll have good soil for making your island self-sustaining.

Natural Light

Natural light is important to your wellbeing. Sky lights can be built into your dome. But, dont cut a strut, put them in the middle of a triangle. If you may have a storm, make covers you can shut over them.

Use skylight approved glass that wont shatter over your head. The cheapest plastic roofing can be used, remember, to shape it to shed rainwater.

My Uncle had a home with a restroom, plastic, non-see-through window for natural light. All inside. That way you wont need electricity to use the restroom.


You have to plan for many things, so that your island will turn out the way you want it.

All of these things should be included in your design. Obviously, neither Dr. Hait nor the Rocky Mountain Research Center bear any responsibility for your design. Its completely yours!

But you may contact Dr. Hait as you need to. Ill try to help as I am able too. Please write us of your experiences so we may use them to help others.