NYLON-CEMENT
- a new construction technique
using nylon fishnet and cement
.
Bill Birdsall
email: Thinkenstein@yahoo.com
____________________________________
Around 1975, the adventure began. I purchased some undeveloped
land on a
mountaintop in Puerto Rico and began to make it my home. It was a
beautiful
area, with a panoramic view of mountains and valleys covered with lush
green
tropical forest. On one side, about a tenth of a mile away, the paved
road
ended, and my nearest neighbors, mostly coffee farmers, lived. On the
other
side were hundreds of acres of forest extending to the river below.
For various reasons, there was no access
road to the building site in those days, and I often had to haul in
materials
by hand from up to a tenth of a mile away. To meet my immediate shelter
needs,
the first structure up was a one-room, 12 X 16 ft. plywood cabin,
raised about
3 1/2 ft. off the ground on cast concrete posts. Design-wise, its major
features were a sleeping loft to leave more floor space open, and
plywood
windows that pivoted up and were held open by prop sticks, creating a
shade
awning effect when open, and a secure closure when down and locked by
heavy
pins.
Although I now have public water,
electricity, and telephone service, for my first eight years I had only
water.
Light was provided by gas lights, kerosene lanterns and candles.
Regular
telephones did not appear in our barrio until about five years ago.
Until then,
there was only a radiotelephone at the "colmado" (small general
store) a couple miles away.
For those first eight years, I dedicated
my time mostly to practicing various fine arts, such as painting and
sculpture,
and clearing some of the forest to plant a variety of fruit and nut
trees.
Since trees take so long to produce, I wanted to get them in right
away.
Fortunately, due mostly to distance from
society, I was able to operate in a way that might not be tolerated in
a major
city. Basically, I was able to develop my ideas spontaneously, testing
experimental and alternative ways of doing things. My home grew
organically,
based on general principles, but no rigid building plan. Learning
through
experience, my success rate with experiments improved over time.
I had several general ideas that I was
working with. For one thing, due to it being the tropics, there are
some
problems with wood, such as termites, "polillas" (like invisible
termites), and wood rot. To some extent, those problems are avoided
these days
by using treated wood, but when I began my building there wasn't much
of that,
and the material most people preferred was cement.
Standard cement construction in Puerto
Rico consists of a massive foundation, with heavy cement block walls,
and a
cast cement slab roof. This involves a lot of material, and due to the
distance
factor, hauling that much material in on my back was not a very
enticing idea.
Also, due to the weight of the structure, any foundation slippage can
cause
serious cracks in the heavy walls. Furthermore, the low cement slab
roofs tend
to absorb a lot of heat during the day and radiate it down at night,
making the
environment for sleeping less than ideal.
Due to the distance factor and the need
to transport materials in by hand, one of my guiding principles was to
do the
most I could with the least amount of material; to look for thin shell
solutions wherever possible. Also, I had been influenced years before
by the
concepts of geodesic domes, and ferro-cement boat building. Geodesic
domes tend
to leak, though, due to expansion problems at their joints. About the
only kind
of domes that didn't have major leak problems were cement domes.
Domes also have the advantage of giving the
maximum amount of internal volume, with the minimum of surface area
material. I
also liked the high ceilings in domes, something which would help keep
rooms
cooler in the tropics, given a heat escape opening at top. The
spaciousness of
domes felt comfortable to me, and as studio workspace goes, it would
allow me
to work on big projects indoors, if the doors were big enough to get
things
out.
The complex curvature of domes also gives
them a lot of strength that the same amount of material in a flat
configuration
would not have. Think of how difficult it is to crush an egg between
your
hands, and how easy it is to snap a cracker. In hurricanes, also, a
dome shape
tends to part the wind, whereas a flat wall would act as a sail. Also,
domes
have no roof overhangs for hurricane winds to grab hold of.
While all of these background ideas were
gestating over the years, several of our hurricane seasons, and a few
close
calls had come and gone. Although my plywood cabin was solidly built, I
felt
that my safety would be best served by making a hurricane shelter. The
opportunity to try my hand at ferro-cement construction, and maybe a
sample
dome structure attracted me, so I began what was eventually to become
my
adventure with nylon-cement.
* The
Hurricane Shelter:
Floor areas in my home were all excavated
by hand using a pick, "coa" digging bar, hoe, shovel, and wheelbarrow
to dump the earth off to the side, and to extend the patio areas. From
the door
of my cabin, looking up the ridge to the south, I began to visualize
the
shelter being half-submerged into the earth, and a large patio area
between the
cabin and the shelter. After a lot of "good exercise", that came to
pass.
Ferro-cement means iron and cement.
Ferro-cement boat construction is done by making the inverted boat
shape as a
basket-like grid of iron rods, tie wired together at their
intersections, and
covered with three layers of chicken wire to hold plastering with
cement. After
plastering inside and out with a 3:1 ratio of sand and cement (with a
little
lime added for extra hardness), the walls are about 1 1/2 inch thick.
At the time I made my hurricane shelter,
I was not yet thinking of using nylon fishnet as a substitute for
chicken wire
in cement construction, so the dome roof of the shelter was done with
standard
ferro-cement techniques. The carved earth areas, though, were shaped
somewhat
like rocks, and I liked their natural appearance. Chicken wire, in
close
proximity to the ground, would probably have rust problems over time,
and as
iron rusts it expands and damages the cement. Furthermore, chicken wire
is not
very flexible. To get it imbedded in the cement, the cement layer would
end up
being fairly thick, and the rocky contours I was hoping to preserve
would be lost.
The solution to the problem finally came
to me when I remembered the nylon fishnet catalog I had mailed away
for,
suggested by one of the "Final", "Last",
"Ultimate" Whole Earth Catalogs. If the nylon mesh material could be
substituted for the iron mesh material, then the rust problem would be
avoided.
Furthermore, the fishnet should be much more flexible than chicken
wire,
allowing for a thinner layer of cement, and a closer following of the
contours
of the carved earth. If the cement did crack, the nylon fibers would
hold the
pieces in place; and at the same time, the cement would protect the
nylon from
harmful ultraviolet sunlight radiation. Thus was born the concept of
nylon-cement. I tried it, and it worked.
* A World
of Possibilities:
OK, things start getting a little bizarre
now. This was exciting! I had what was, as far as I knew, an original
material
combination, and I was eager to explore all of its potential uses. I
began
envisioning projects above, on, and below ground level.
Due to the flexibility of the material,
there were no limitations as to form; something that attracted me no
end as an
artist. Any shape I could carve into the earth, I could preserve with
about a
1/4 inch thick layer of nylon-cement. That could include floors,
stairs,
outdoor furniture, ponds, septic tanks, walkways, retaining walls, and
who knew
what else?
Above ground, so long as the fishnet
could be supported until the cement hardened, any form was also
possible.
Growing out of ferro-cement technology, the first support material that
came to
mind was iron rods, which is what I used to make the above-ground
portion of my
house. In recent years, I have also been stretching the netting out
like a tent
over pole supports, and then removing the poles after the cement
hardens. This
has an advantage in that it completely avoids any future problem with
iron rods
rusting and damaging the cement.
I have always loved caves, and so
thinking of taking nylon-cement underground, and making tunnels was a
natural
evolution of its potential for me. I began to visualize digging
something like
a deep well between the plywood cabin and the hurricane shelter,
horizontal
tunnels leading to a hillside entrance, and then a big dome room which
would
unite the cabin, the hurricane shelter, and cover the opening to the
vertical
shaft.
* The
Vertical Shaft:
In order to have good lighting for
digging the vertical shaft, I decided to postpone making the roof of
the main
dome room until the shaft was completed.
The next problem was how to dig the
shaft, since I was living and working alone. The horizontal tunnel I
was
imagining would eventually pass underneath the plywood cabin. In order
to feel
secure that the whole thing would not just collapse, I eventually ended
up
going down 30 ft. from the floor of the main room to the floor of the
tunnel,
before starting to dig sideways.
Although with the nylon-cement, I could make
a perfectly cylindrical shaft, I decided, mostly for esthetic reasons,
to carve
the dirt like rock boulders. This would also give me the advantage of
being
able to rock climb the walls in order to get up and down, instead of
having to
work around a ladder. This solution ended up working very well.
The problem of how to raise the dirt I
dug, and how to dump it off to the side of the shaft was solved in an
inventive
sort of way that smacks of Rube Goldberg. Basically, I welded up two
vertical
pipes and a horizontal pipe that passed over the shaft, connected to
the tops
of both poles. Pulleys were attached to the horizontal pipe. An arm
that hinged
on one of the vertical pipes, and was controlled by ropes dangling down
into
the shaft from the pulleys, had a hook and releasing mechanism for
holding a
bucket on a rope. From the bottom of the shaft, using only ropes, I
could hoist
buckets of dirt, have them hook onto the arm, swing to the side of the
hole,
dump the dirt behind a barrier, return over the shaft, disengage, and
return to
the bottom of the shaft for more dirt. The bucket could also be used
for
sending down loads of cement for plastering the walls.
For safety's sake, I dug the shaft in
sections, about 5 ft. at a time. After plastering one section, I would
dig the
next, and plaster it leaving some overlapping of the nylon-cement
layers.
Having finished the vertical shaft, I postponed digging the horizontal
parts of
the tunnel, giving priority to the construction of the above ground
parts of
the house.
* The
House Foundation:
The nylon-cement technique I was using for
the main room included the use of a basket-like grid of iron
construction rods
about 10 inches apart, as in ferro-cement boat building. I was
convinced that,
because of the relatively thin walls, and the strength of the complex
curvature, there would be little need for a massive foundation. The
main
purpose for the foundation would be to prevent undermining of the walls
from
erosion. I ended up doing a foundation only about a foot deep, and
maybe eight
inches wide.
Suspended off the bottom of the
foundation trench was an iron rod. Tie wired to that rod were pieces of
rod
shaped like staples, their legs aimed up. Those rod stubs were the base
upon
which further rods were tied to begin defining the walls-to-be.
Although I
didn't actually fill the foundation trench with concrete until most of
the rod
work was up, I now normally pour foundations, locking in the rod stubs,
before
defining the walls.
* Defining
the Form of the House:
Standard architecture, in most of the
world, is composed of boxes, and I am more than a little tired of
seeing so
many boxes cluttering up the beauty of nature. To me, the most
esthetically
pleasing architecture is invisible architecture, or failing that, at
least
architecture that combines gracefully with nature.
One sees very few
straight lines in nature, and therefore all
the straight lines in conventional architecture stand out like sore
thumbs on
the landscape. The flexibility of nylon-cement allowed me to compose
using
free-form curves, and irregular, sculptural forms, which combine much
more
gracefully into the environment.
On the ground, nylon-cement is not poured
into straight-edged wood molds, but is rather laminated over sculpted
earth
shapes. In the air, the easy shapes to make are domes, or tent shapes.
Frames to define door openings were made
out of welded pipe, and set in the foundation concrete. I experimented
with a
variety of heavy-duty hinge systems. Each of the doors is made in place
out of
cement, the same as the walls, and weighs on the average about 600 lbs.
For
security, and other reasons, I decided not to have a lot of windows.
There are
some skylights (street light lenses) set into the walls with silicone
rubber to
avoid cracking from different thermal expansion rates. For the most
part, the
very large, gate-like doors take the place of windows.
Surprisingly, there are not many truly
bothersome insects out in my neck of the woods, if one is very careful
not to
breed mosquitoes in carelessly discarded trash. Living as far as I do
from my
nearest neighbors, I don't share the community mosquitoes that they
breed. I
have no need for screens on my windows, little to no need for a
mosquito net at
night, and I leave the doors open most of the time for ventilation. The
line between
indoors and outdoors is intentionally blurred in my house design.
The design for my house evolved over
time. Every morning, I would open the door to my original cabin,
visualize the
possibilities, and work spontaneously. There was no master plan, and
directions
were free to change as inspiration came. The construction process was a
non-stop adventure.
A normal house, given a construction
crew, and a blueprint, goes up relatively quickly, and when things are
up they
tend to stay up. There is not much design flexibility once construction
begins.
Working alone with my new techniques, however, the form evolved fairly
slowly
in the first stage of making the iron rod support structure. Unlike a
blueprint
on paper, this 3-dimensional representation of what the house was going
to be
like could be walked through and experienced prior to finalizing the
form with
cement. If I rubbed my shoulder on the wall in passing, I could always
untie
the rods and change them.
Just as boxes can be boring, perfectly
symmetrical domes can get to be uninspiring also. Therefore, I
distorted the
basic dome concept in ways that helped better meet my needs and
esthetics, and
better conform the structure to the lay of the land.
Storage of possessions is always a
problem. In most houses, overhead space under the roof goes to waste. I
solved
a lot of my storage problem, and avoided the expense of cabinets
throughout
much of the house by setting iron rings in the walls and ceilings. The
rings
are firmly attached to the iron rods inside the walls, so they can
support
tremendous weight safely. Using iron "S" hooks, rope loops, and
sometimes sacks, I can hang almost anything overhead (usually
light-weight
things) or on the walls. Also, to multiply the number of rings to hang
things
from overhead, I welded up big link chains out of more rod material,
and
attached the chain from ring to ring in the ceiling. Each link in the
chain
gave me a new point to hang things from.
Another design element in the house is
the sloping floor. The slope is not great enough to interfere with
normal floor
use, but it all slopes for drainage, so the house can be easily hosed
out if
desired. Also, the slope connects the patios on either side of the
house in
such a way that there are no steps to deal with in getting from one
elevation
to another.
The traffic pattern in a boxy house tends
to include a lot of right-angle turns. In my house, the traffic
patterns tend
to spiral around, with no need to slow down for corners. Also, there
are
changes in elevation that make for interesting variations in point of
view. On
the way up to the upper story bedroom, for example, after climbing the
steps
behind the vertical shaft, there is a stop at a loft area in the main
room. The
main room has a 15 ft. high ceiling. From the loft you can look down
into the
main room, and also about 40 ft. straight down to the bottom of the
vertical
shaft -- a breathtaking sight. A spiral stairway then leads up through
a hole
in the ceiling to the bedroom upstairs.
The bedroom has a spectacular, treetop
level view out over the valley, through big, cave-like window openings.
The
floor of the bedroom is domed, not flat, and the bed hangs off the
floor by
cables from the ceiling, and swings like a hammock. One has access to
the
rooftop by climbing out the windows and up a little stairway. Vines
cover the
exterior of the house, making it more invisible, shading it, and
providing some
fruit.
I use both cement-base and elastomeric
roof sealers on the exterior of the house. On the inside, I do not
color
surfaces with paint. Instead, I splatter on pigment-tinted cement.
Interestingly, although I find that spiders build webs on painted
surfaces,
they don't seem to like raw cement. Without any maintenance, the walls
and
ceiling appear just as they did when new.
My original plywood cabin served me well,
and it was nice to have at least a little flat and level floor, and
standard
storage areas. Eventually, the plywood roof needed replacing, but by
that time,
it had been partially locked in by the cement part of the house, and
could not
be replaced without leak problems at the joint with the cement. I
solved that
problem by tearing off the rotten part of the roof, and building a
whole new
cement dome room which completely enclosed the old cabin and attached
more
easily to the newer, cement part of the house. The end result is a very
interesting utilization of space, which combines boxy and rounded
elements.
To begin with, I removed some of the
original plywood wall areas, to allow better ventilation in the room,
and
visual entertainment from see-through areas. Then, since the old
plywood window
closures were no longer needed, I removed them from their overhead,
hinge-up
positions, and moved them to the bottom of the window openings,
suspended
"outside" the openings for use as table surfaces. This gave me a lot
of table area without sacrificing any floor space. Since the plywood
room is up
on stilts, one can easily walk underneath the tables on the other side
of the
wall.
* The
Outdoor Bathroom:
During my first years on the land, I had
a very simple bathroom solution -- a shovel to dig and fill latrine
holes in
the woods. During that time, I came to prefer the spaciousness of my
bathroom
to the more cramped quarters you find at most homes. The sights and
sounds of
nature were more entertaining than wallpaper designs.
When my mother decided to visit me,
though, she informed me that a basic prerequisite for her visit would
be a
"civilized" flush toilet. Thus was born my compromise solution, which
has become the most popular element of the house tour.
First off, being the do-it-myself person
that I am, I decided to make my own flush toilet. Secondly, since I
would be
the one using it most of the time, I decided to put it outdoors, where
I liked
being. Acknowledging that it is sometimes nice to have a roof over
one's head
when it rains, I also decided to put a sort of glass umbrella over it.
The toilet bowl was formed with
nylon-cement over a sand pile mold (kind of like a sand castle shape).
The tank
is a plastic drum with standard toilet valve hardware located at a sort
of half
way height between that of a modern toilet and the old chain-pull type.
It has
very good water pressure, and flushes nicely.
The
septic tank next to the toilet is an eight-foot deep nylon-cement lined
hole
with a leach line, and is covered with a hollow fake rock with an
access door.
The bathroom area is quite large, and although open to sky, trees, and
birds,
is now completely surrounded by a privacy wall. The shower is in sort
of a
grotto area off to one side.
Bathroom
maintenance is not very time consuming. There is no tile to clean.
Basically, I
just go in about once a month and rake the leaves out.
*
Walkways, Stairs, and Retaining Walls:
Weeds
grow fast where I live, and clay dirt trails can be slippery when it
rains. To
solve both problems, taking advantage of the economical nature of
nylon-cement
( 1/4 inch of cement, and free, discarded fishnet ) I ended up
plastering most
of my trails and hillside stairways.
Usually,
carving anything into a hillside results in a vertical cut face on the
uphill
side, and a need for a retaining wall to keep dirt from eroding down on
the
walkway below. With nylon-cement both horizontal and vertical surfaces
can be
plastered at the same time. Although retaining walls can be shaped in
any form,
I usually carve the dirt to look like rock boulders, to keep things
looking
natural.
To
avoid erosion undercutting of the edges of patios, walkways, and
retaining
walls, I usually dig a shallow trench at the edge, and wrap the
nylon-cement
down into the trench. After back filling the trench, the edge is
buried, and
protected from undercutting.
Since
I live in the mountains, a lot of my walkways include stairs. I have
come up
with an unusual stair design that is an improvement over normal stairs
for
steep slopes.
With
normal parallel stairs, as the slope increases, the height of each step
increases, and the available space for placing the foot decreases. My
solution
was to take the stairs and carve them in such a way that they intersect
with
each other at a 90-degree angle. That allows for more steps, so the
height of
each step is reduced. It also gives the diagonal distance on the step
for
placing the foot, so there is more room for the foot. Most visitors
find the stair
design to be more comfortable and safe than standard stairs would be on
steep
slopes.
* Trash
Rocks:
Probably,
one of my best ideas has been involved with trash disposal. Recycling,
and the
world's inundation by trash have been big concerns of mine over the
years. On
my personal level, I have solved that problem by making "trash rocks"
out of the waste materials I cannot recycle otherwise.
To
begin with, the nylon fishnet I use to make trash rocks is a discarded
waste of
the fishing industry. What I do is a constructive reuse of material
that is
otherwise not disposed of in ecologically sound ways. I cut out
sections of
net, and sew them into big sacks. I then fill the sacks with my
un-recyclable
trash, sew them closed, take them where I want them, and plaster them
with
cement.
The
end results are cement "rocks" that can be used for benches, tables,
statue bases, landscaping, or for building walls. They are strong, and
have at
least some thermal insulation.
* The
Underground Tunnel:
Fortunately
for me, the ground where I live is composed of clay soil and a
relatively soft
rock known as "tosca", which is kind of like hard clay. It is soft
enough to dig through and, although there is always some risk of
cave-ins, I
felt secure enough tunneling through it as I aimed to connect with the
bottom
of the vertical shaft in the main room of the house.
After
using some primitive surveying techniques to decide where to start the
tunnel
on the hillside, I dug a patio area where I could mix cement. Digging
the patio
also let me get to the tosca, below the soft topsoil layer, in order to
safely
begin tunneling.
The
tunnel was designed with a slight slope toward the doorway, so that any
water
in the tunnel could always find its way out. Instead of making it a
straight
tunnel, I decided to make it snake around in an interesting way. I
wanted
walking through the tunnel to be an esthetic experience. Straight
tunnels are
not as interesting as curved ones.
The
tunnel has, basically, an arched ceiling, which is a strong shape. It
averages
about 4 ft. wide, and about 7 ft. in height. The tunnel, from the
hillside
entrance to the vertical shaft, is about 100 ft. long. There is an oval
room,
about 8 ft. wide and 12 ft. long half way along the tunnel, and a
branch tunnel
that goes about 50 ft. off to one side. I suppose I have spent about 4
or 5
years working underground.
Due
to entering soft material, and a cave-in problem at the end of that
tunnel
branch, I had to finish it by making another vertical shaft to the
ground
surface above, and covering the hole with a dome roof. It has a
skylight, a
ventilation opening, and an emergency escape hatch.
All
branches of the tunnel have ventilation, which reduces humidity, but
there is
still too much humidity for leaving many things down there. Mildew does
not
attack cement, but it does attack most other materials. Even though I
wouldn't
live down there full time, it is a comfortable place to spend time and
do
things, especially during hot summer days.
*
Technical Information:
I
have left this technical information for last, since many people may
not be
interested in actually working with nylon-cement. For those who do love
to roll
up their sleeves and get dirty...read on. I am, by no means, an
engineering
expert, but here are some of the game rules I have played by.
First,
here is some basic information about cement. Sacks of cement, fresh
from the
production plant, are hot. Fresh cement is hot, dry, and powdery. From
there
on, a process of hydration and hardening up takes over. Whether or not
it
hardens up to the maximum depends on the conditions under which it
absorbs
water, and the time it has for crystals to form in the process.
In
Puerto Rico, cement comes in paper sacks, with no plastic lining
inside, so
over time the cement can absorb water from the air and go bad. At first
you
find little rocks of hard cement mixed in with the powdered cement.
Eventually,
the whole sack hardens up. Obviously, you can't mix hard old cement
like you
can fresh cement, so you either want to use the cement as soon as
possible, or
you want to protect it from atmospheric humidity. This can be done by
putting
the sacks in plastic trash bags, or in my favorite containers, 5-gallon
plastic
buckets with lids.
When
you mix cement with water, crystals begin to form within the cement,
and
eventually turn the cement into a rock-like substance. Cement begins to
harden
fairly quickly, and the hardening curve is pretty steep in the first
few days,
but then it levels off pretty much and only slowly reaches its maximum
hardness, after about 28 days, I believe. Anyway, keeping the cement
moist for
the first day, or two is important. If it dries out, hardening stops,
and
getting it wet again doesn't continue the hardening process.
When
cement dries out, it becomes a porous material. Between the latice-work
of
crystals, where the extra water was, air takes the water's place. The
denser
that latice of crystals is, the stronger the cement will be. For that
reason it
is good to not use more water than necessary when mixing cement. Runny
cement
has its uses at times, to penetrate where thicker cement won't go, but
if
thicker cement will do the job, use it.
When
cement dries out, not only does it become porous, but it also shrinks.
In order
to avoid excessive shrinking, and cracking, a non-shrinking filler
material has
to be added to the cement. A good way to remember the correct ratios
for mixing
the components is to think "1-2-3". For mixing concrete (for
foundations), it is 1 part cement, 2 parts sand, 3 parts gravel. For
mixing
cement for plastering (most nylon-cement uses), the ratio is 1 part
cement (to) 3 parts sand.
Also,
from what I have read, throwing in about a shovel full of construction
lime to
each sack of cement mixed for plastering will help the finished cement
harden
up more. The lime and cement react with carbon dioxide in the air to
form the
mineral aragonite. It is hard for me to tell the difference, but I
always throw
in a little lime when I mex cement for plastering jobs. Since this
benefit of
lime only works in the presence of atmospheric carbon dioxide, there is
no
reason to add lime to massive jobs of poured concrete in foundation
ditches,
etc.
I
mixed all the cement for my house by hand. To do that, you need a good
mixing
surface (like my front patio area), a source of water, and a
square-nose
shovel. First, dump your sand on the mixing area and spread it out a
little
with the shovel. Then, dump your cement in the middle of that. Add a
little
lime, if you choose to. Walk around the pile, turning it over with the
shovel
to mix the dry materials. I usually make a little mound, tossing each
shovel of
sand and cement on the side of the pile, letting them mix as they slide
down
the side.
When
you get the dry material roughly mixed and in a pile, take the shovel
and open
up a hole at the top of the pile. This is where you will add the water,
filling
it like a lake at the top of a volcano. Experience will tell you how
much water
to add, and usually the safest way to avoid adding too much water is to
use
less than necessary at first, adding more little by little until you
get it
right.
When the cement is mixed, shovel some into the buckets for carrying it to the work site (5 gallon plastic pails are what I use). Basic tools for plastering include a trowel (I make my own out of PVC plastic), and rubber gloves. Cement will eat holes in your skin, so be careful with it. Heavy-duty long-sleeve rubber gloves are best. Unfortunately, most stores only sell short-sleeve gloves. I sometimes cut the sleeves off of old gloves and use them as sleeve extensions, using heavy rubber bands I also cut from old rubber gloves to hold them in place.
To
put a layer of nylon-cement on the ground, first you have to shape the
ground.
A pick, shovel, hoe and machete are useful shaping tools, and a broom
tidies up
the surface. Next, usually working in the late afternoon, so that the
cement
will harden in the cool humidity of the night without further attention
from
me, I splatter down a soupy "paint coat" of cement and water,
flinging it down with a big cement worker's brush. If the color of the
dirt
shows through, the mixture is too watery. If it doesn't splatter
easily, the
mixture is too thick.
After
letting the splash coat harden overnight, it can be walked on the next
morning.
Spread out the fishnet and trim the edges. If the fishnet has a very
fine mesh,
I sometimes do a first coat with soupy plastering mix, working it
through the
mesh with a gloved hand, and then a thicker, second coat immediately
over that.
To provide better traction, when the cement starts to harden up a
little, I
usually give it a little texture by brushing it with a broom.
When
plastering fishnet in the air, it needs to have the weight supported
until the
cement hardens. If a grid-work of iron rod is used as the support
material, I
usually try to keep the tie wire snags on the inside of the structure,
so that
I can stretch the fishnet over the rods without dealing with snags all
the
time.
First,
I stretch the fishnet and attach it to the rods with wire. The fishnet
is
still, basically, a loose skin over the rods. If one begins plastering
the fishnet,
from the bottom up, eventually the weight of the cement will stretch
the
fishnet, it will form ugly wrinkles, the cement will crack, fall off,
and the
air will be filled with foul language. To avoid that problem, one has
to rub
cement over the rods, through the fishnet, to adhere the netting to the
rods.
That way, after the cement hardens over the rods, whatever is done to
any
square in the grid will not affect neighboring squares.
Keeping
in mind that one has to prepare the area that way in advance of
plastering the
walls, what I then do is plaster the outside as far up as I can reach
the first
day (using a gloved hand to apply the plaster and the trowel to smooth
it
some). On Day Two, I plaster the inside up to that height. On Day
Three, I
stand on a 55-gallon drum and plaster the outside as high as I can
reach. On
Day Four, I plaster the inside of that. On Day Five, I can lean a
ladder
against the wall and do the next stage. On Day Six, I plaster the
inside of
that. On Day Seven, I can start climbing onto the cement, and on
alternating
days do inside and outside until I reach the center. Toward the center
of the
roof, one needs bamboo poles, or other supports, to keep the weight of
the
cement from buckling the dome ceiling downward, until the cement
hardens.
In
plastering the underground tunnel, I had to use a modified technique,
especially on the ceiling. Those who have ever plastered a ceiling know
that
some areas of wet plaster inevitably let go and plop to the ground. If
they are
connected to a big piece of fishnet, they can pull the whole thing
down, which
can be very, very frustrating. I solved that problem by using a
two-stage
plastering process, which also resulted in thicker and stronger walls.
I also
found that bigger mesh fishnet, about 1 1/2 or 2 inch mesh was best,
because
the cement has to penetrate the holes easily in order to stick to the
ceiling
and walls.
The
two stages for tunnel plastering are as follows. First, the walls and
ceiling
are plastered without fishnet. Lots of staple-shaped pieces of wire are
embedded in the cement, with their legs sticking out. When the cement
hardens,
these wires are used to hold the fishnet in place. If plaster on the
ceiling
lets go and starts to pull on the fishnet, the disaster will run only
as far as
the next holding wires. I have learned to use lots of these holding
wire points
in the ceiling.
The
tent-like technique for above ground structures, which uses no iron
rods, is
actually pretty simple. One has to use a fine mesh netting. After
locking the
base of the netting into the foundation concrete, poles are used to
stretch the
netting out like a tent. Then, using a can on the end of a pole, runny
plastering mix is dribbled over the tent. It can be applied by hand in
areas
where one doesn't have to lean against the structure. When the outside
layer is
hard, the inside can be plastered, leaving the removal of the poles,
and
touch-up in the cavities they make for last. In the garage I made with
this
technique, I used treated wood in the door frame, and stapled the
fishnet to
the wood.
* Some
Final Thoughts:
To
me, the extreme design flexibility of nylon-cement liberates fantasy.
What I
have done with it is only my fantasy. It would be fascinating to see a
world
that took nylon-cement potential to its limits.
One
of my experiments was to put a dome on top of a dome; the bedroom on
top of the
main room. I can imagine cities built something like piles of soap
suds, with
dome rooms of different sizes, and ventilation and light access kept in
mind
with the over-all design. Such cities might grow over time, with people
occupying the outer layers, and the more antique cores used for
storage, or
other purposes.
Given
the usefulness of nylon-cement for lining tunnels, I can also imagine
underground communities. There are already troglodyte communities in
different
parts of the world, mostly in drier climates than Puerto Rico, so maybe
my
underground humidity problem would not be a problem elsewhere.
Nylon-cement
material, in thin layers on the ground, is also fairly easy to break up
and
remove, so that replacement as future needs evolve is not difficult.
Old
nylon-cement material makes pretty good fill material in roads, if
nothing
else.
Also,
nylon-cement technology is not especially difficult, and the strength
of the
material can allow for practical success even in less than optimal
designs. I
think it would be a good self-sufficiency technique for all of society
to know.
It would perhaps reduce the need for contractors, for one thing, the
cost of
housing, and the cost of living. If children made their own schools
with it,
they would learn how to meet their own needs later in life.
Since
cement doesn't have to be worked in large quantities at one time, it is
potentially within the strength capabilities of women and children. Not
only
could it provide more independent self-sufficiency for people in
general, but
also for women in particular. Construction is, at the moment, a
male-dominated
industry. Nylon-cement techniques could change that.
My adventures with nylon-cement have provided me with some of the most interesting years of my life. Necessity being the mother of invention, I was always inventive, exploring for new and better ways of solving problems. The experiments were, for the most part, successful, and I hope my experience will inspire others to continue where I have left off. A free-form world of nylon-cement would certainly be an interesting world, and maybe a better one.