Posted MAY 30, 2003: In 1992 we started
designing our own “fieldhouse” structures that
would help us get a jump on the season and be very low-tech
and simple to build and dismantle. We termed these structures
"fieldhouses" because they are temporary, sit directly
on our growing fields and lend themselves easily to rotations--an
invaluable crop management practice for disease and insect
We utilize two homemade designs that have worked well for
us, one with metal hoops and one with PVC plastic hoops. In
the fall, two metal-hooped houses are constructed and remain
up all winter, since they can withstand snow loads. In the
early spring (March), one or two plastic-hooped houses are
constructed. All the houses are dismantled by approximately
June 1st when all danger of frost has passed.
This design with PVC hoops is only used in the spring
(and sometimes in the fall), since it is not able to withstand
any snow load. Ours have gone down to the ground several times
with snow and they actually do spring back up nicely, but
eventually the pipes will break! Total cost of the plastic
house was about $600 when we built ours years ago (no labor
The standard fieldhouse we build is 14 feet wide and 96 feet
long. This design uses twenty-five 1-inch by 20-foot plastic
schedule 40 PVC pipes for the hoops (for a 96-foot house).
Two 100-foot strings with stakes attached to each end are
set up parallel to each other and 14 feet apart. These are
used as guides to keep the house in an approximate rectangle.
1-1/4-inch galvanized pipes approximately 2 feet long are
set along the strings every 4 feet.
The pipes are then sledgehammered into the ground as close
to the string as possible; if you have rocks like we do, a
pipe can be moved a few inches either way up or down the string.
If the pipes are being re-used, the dirt must be removed from
them first by tapping them together (great kid job!). We place
a 2 x 4-inch board on the pipe to prevent damage to the top
of the pipe as we hammer. About 6 inches of pipe should be
left above the ground. Most of the pipes we use have been
obtained free from fencing companies, who, in our area, throw
away pipes shorter than 3 feet. The plastic hoop ends are
then placed into these metal pipes.
Next we attach 1 x 4-inch rough-cut boards along one side
of the fieldhouse about 3 feet off the ground to create a
vented side. It is best to choose the side that does not get
the prevailing wind. Pre-drill holes on the boards every four
feet, starting about 2 inches from the end and a little below
the center of the board. Secure the boards to the plastic
hoops wit 5/16-inch U-bolts (they come in all different sizes
but we use mostly 2 x 2-1/2 x 5/16-inch, zinc-plated) with
the nuts facing the outside of the fieldhouse. The U-bolts
go through the pre-drilled holes.
Shorter wood scraps (15 to 18-inches long) are used to strengthen
the areas where the separate boards meet. Wherever two boards
butt together, place a short wood scrap behind and then place
3 screws (1-1/4 to 1-1/2 inches) on each side (6 total per
joint). Depending on how far the bolts stick out beyond the
boards, we either countersink the nuts or wrap two layers
of duct tape over the ends of the bolts to prevent damage
to the greenhouse film. We duct tape a piece of carved rigid
foam insulation on both ends of the boards to protect the
greenhouse film; it can be saved and used for many years.
tape marvel: The ridge pole (this fieldhouse
has two--only one shown) and side diagonal braces
are attached by duct tape--perfect for this temporary
The ridge pole is a series of 5 additional PVC pipes (each
20 feet long) which are duct taped as straight as possible
to the inside of the hoops and down the center. The pipes
are overlapped about 10 to 12 inches and wrapped with duct
tape, especially on the cut ends that could damage the plastic.
Side diagonal bracings (PVC) are attached by duct tape, 2
on each end, starting at the ridgepole at the greenhouse ends
and ending at the ground level, attaching to each of the 4
hoops they cross. At both ends of the fieldhouse at the peaks,
the pipe ends need many loops of duct tape to stay put. Two
wrappings of duct tape are usually all that is required every
other place a PVC pipe crosses another pipe. Remember, these
houses are only temporary.
A trench 6 to 8-inches deep is dug along the side of the
fieldhouse that does not have the vented side (and board).
The trench will hold one end of your greenhouse film and should
be dug very close to the outside of the metal posts. The end
walls are pre-made units of 2 x 4-foot construction that utilize
a 4-foot-wide x 5-foot-high door and are permanently covered
with plastic (lathed on). Our doors are 4 feet wide to accommodate
our harvest wheelbarrows, but can be made to any size that
works best. These removable end units are screwed into four
2 x 4 x 2-foot-long stakes. The stakes are sledgehammered
into the ground about 10 to 12 inches and two 3-inch sheetrock
screws are used to secure each stake.
We use 3-year greenhouse film (24 feet by 100 feet) which
is lathed and screwed onto the end units when the winds are
totally calm (always roll the lathe/plastic under for rain
drainage), then the one side is buried into the trench. It
is important to pull the plastic tight in all directions before
securing. If the plastic is buried too deep into the trench,
it can’t be pulled up easily by hand, and if it’s
buried too shallow, it pulls out with the wind. Practice makes
perfect! The other side is secured to the side boards by screwing
lathe strips on the top part of the boards, and the plastic
can then be rolled up for venting when spring temperatures
reach 60°F to 70°F.
the crop: A simple string system holds
the rolled plastic off the ground when more air
flow is needed.
We use a simple string system to tie up the plastic every
8 feet. One end of the string is tied onto the side board
through a 1/2-inch hole we drill on the lower side; then,
after the plastic is lifted or rolled up, a small tied loop
at the other end of the string is hooked over a screw partly
inserted into the lathe strips above the drilled hole. Again,
roll the plastic under before securing so rain runs off, instead
of inside, the plastic rolls. If you have strong winds, the
vented side plastic can be secured to the ground with cement
blocks on top of boards. These are temporary structures and
are not designed to withstand heavy winds, but we never have
problems if both sides are secured down.
It takes us about 8 hours with 2 people to put one up and
a lot less time to dismantle! We dismantle the 1 x 4-inch
boards in sections, and number them as we go (leaving the
short scrap wood pieces attached to one board), so they can
be pieced back together the next season.
The piecing together of this design is similar to that
of the plastic-piped structure. Total cost of the metal house
was about $800 when we built ours years ago (no labor included).
This design uses twenty-five 3/4-inch galvanized water pipes
that are 21 feet long. These are available from any plumbing
supply facility and cost about $23 each in our area. We bend
the pipes ourselves into a half-circle using a jig with about
twenty short pieces of 2 x 4-inch boards (about 8 to 10-feet
long). The boards are each attached with 2 screws onto our
hay wagon about one foot apart. The one end of the pipe is
attached to the wagon with 2 boards, then one person merely
“walks” the pipe around the jig until it touches
the last small board. Next, using a pipe bender, we bend the
peak to be gothic style, bending until an attached string
shows the ends are 14 feet apart. Finally, a slight bend is
put six inches from the end of each pipe, so the hoop drops
into the fence pipes easily.
If this type fieldhouse is used only when there will be
no snow, the pipes can be placed every 6 to 8 feet instead
of every 4 feet. This type of fieldhouse is utilized all winter
on our farm and it can take almost any snow load. However,
we often remove the snow using a large push broom and clear
along the sides if necessary with shovels or a front-end loader,
mostly to get light to the plants inside faster. During the
winter, the plastic on both sides is buried in the ground.
All other details of construction are similar to the plastic
house as described above.
Duct tape is used to bind everything together and to tape
over bolts, pipe ends, etc. to protect the greenhouse film.
The greenhouse film usually lasts us 6 seasons, but often
as many as 9 seasons. We fold, label, and store it in a dark,
cool place (rootcellar). Screws and not nails are used when
needed for ease of removal and reuse of all materials, and
the specified lengths can be changed depending on board widths,
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