On-Farm Construction
Most farms will eventually have a construction project to add new
facilities or improve existing ones. Depending upon the skill of the
owner and scope of the project, these may be done on the farm with
or without the help of a contractor.
e rst step is to check with local town or city ocials to see if
there are requirements for building permits, zoning restrictions or
set-backs from property lines, water bodies, or adjacent wetlands.
Building codes will especially have standards for foundations and
roof snow loads. It’s good to start o right with these ocials and
perhaps even get some good input for your project. If you are the
builder, you take on the role of organizing the project and oen
serve as a general contractor, arranging other services such as
excavation, concrete pouring, etc., to get the job done.
Lean-tos can be a low-cost solution to adding space, but may have
limited access and compromise the existing structure.
Before building any structures, the
rst step is to check with local town
or city ocials to see if there are
requirements for building permits,
zoning restrictions or set-backs
from property lines, water bodies, or
adjacent wetlands.
Bringing information and education into
the communities of the Granite State
A pole barn with clear-span trusses is a good building option for many farms.
If adding a lean-to onto a building, make sure
the side wall is high enough for the addition to
maintain the slope of the existing roof and still
have adequate height at the eaves for air ow and
equipment passage.
Lean-to Addition
▼
UNH Cooperative Extension • 2
Site
In New England, selecting a site for a building project can be a
challenge. A lot of farm buildings were built on the worst land so as not
to use up good cropland. When these old buildings were added onto, it
oen perpetuated poor location issues.
Here are a few factors to consider when determining the site of a new
building:
• Access
• Topography
• Orientation to the sun and prevailing winds
• Drainage
• Area needed plus room for future expansion
• Environmental concerns
• Distance from other buildings
• Soil type
• Utilities
e temptation is to choose a site and immediately start building.
e problem with this is that the existing topsoil won’t drain adequately
and water will ow into the building from roof rainwater and surface
run-o. Spend time removing the topsoil and adding a gravel base larger
than the building to promote ow away from the structure. Follow these
steps:
1. Remove topsoil
2. Add a raised gravel base larger than the building
3. Provide access roads
4. Install needed drainage systems
5. Lay conduits for running underground electrical wiring and
plumbing
Foundation
e foundation will establish the dimensions and squareness of the
building. Any inaccuracies will follow you throughout the project.
Foundation options are:
• Concrete foundation
• Pressure-treated posts
• Pre-cast or poured post bases
• Concrete slab
In New England, a concrete footing with a four-foot frost wall is a
common practice. e footing is poured rst and is larger than the
thickness of the wall. Vertical reinforcing rods placed in the footing
tie the wall-pour to the base. ere are post brackets which can be
embedded into fresh concrete and make a rugged mounting for a post
Laminated post on a pre-cast concrete
base.
Spend time removing the topsoil at the
site and add a gravel base larger than
the building to promote ow away from
the structure.
UNH Cooperative Extension • 3
on a wall. is can eliminate the need of burying a post in the
ground and provide durable side-walls for scraping against.
With post construction, you can bury the posts to a depth of four
feet, or use pre-cast concrete bases or concrete tubes at the base of
each post. ere is a growing concern about how well the wood
preservative treatment penetrates large-dimension posts, so
laminating smaller stock, which has deeper penetration, may help
ensure a longer lifespan of the building. In many instances, the
frost wall may be a better option, and it provides rugged side-walls
for containing bedded-packs or scraping manure.
A concrete pad can also be used as a base for a building. ese
are oen built aer the pattern of an “Alaskan Slab,” with thicker
concrete poured around the edges and perhaps some rigid foam
insulation along the sides to prevent heaving.
Building Construction
ere are several building options for a barn. ese include:
• Conventional stick framing
• Post-frame
• Hoop structure
• Greenhouse
e traditional method of construction in the mid to late 20th
century was “stick built”. is uses 2 x 4 or 2 x 6 framing material
attached to an upper and lower plate and fastened to a oor deck
built on a concrete wall.
Many farm buildings have high sides, open fronts and several large
doors and are more rugged and easier to build as pole buildings.
Very little concrete needs to be poured and native lumber can be
used for vertical siding.
A pole building has the posts either in the ground or sitting on a
support and posts are oen 8’-12’ apart. ey are held together
with a plate on top that supports the roof structure and horizontal
nailing girts along the side for attaching the siding.
Other options for farm buildings include vinyl-fabric hoop
structures and greenhouses. ese have the advantage of letting
in some solar radiation, and they can be disassembled and
moved when no longer needed. Depending upon their size, these
structures may be built on pipe supports, wooden sidewalls or
concrete foundations. e disadvantage is that the roof covering
has a shorter lifespan than traditional coverings, and animals may
chew on the fabric if it is within reach.
The hoop structure provides a lot of
exibility for uses with animal housing.
The top part of each end should be covered
with shade cloth to provide ventilation.
Side “pony walls” can provide a space for
curtains and protect the roof material from
animal damage.
Typical pole barn with the side open to
the south.
One-slope pole barn.
UNH Cooperative Extension • 4
Roofing choices may be
somewhat determined by
the style of construction
and intended use of the
building.
Did You Know?
Fasteners
Proper fasteners need to be selected for the job. Generally nails, bolts,
and lag bolts are used in farm construction. Galvanized nails will
prevent rusting stains on siding and will last longer. Pole barn structures
require the special ring nails that anchor tightly. It is important to select
fasteners that are rated for pressure-treated wood when using that
material, because the chemicals can react with the fastener and cause
a failure.
Phillips head screws can be used for wood construction. Square-drive
heads or star-heads may be preferable in applications where things may
have to be removed, as the drive bits ts more securely and the screws
come out easier.
Roong
Roong choices may be somewhat determined by the style of
construction and intended use of the building. e roong choices are:
A. Wood surface with tab shingles or non-tabbed architectural shingles
B. Metal roong (painted or coated steel)
C. Aluminum roong
Traditional “stick-built” structures oen have a plywood roof covered by
tab shingles or the non-tab, architectural shingles.
Trusses are oen used on pole buildings. ese are pre-engineered
roof members with internal braces, which allow a clear-span building
without internal posts. We recommend buying pre-built units, as the
engineering is critical to their strength. Proper cross-bracing to tie
Truss roof construction is popular because it eliminates the need for interior posts,
making the use of the space very exible.
UNH Cooperative Extension • 5
the trusses together is critical, so follow manufacturer’s specications. Purlins are 2 x 4s spaced apart and
nailed to the top of the trusses for supporting the roong material. Metal (painted or coated steel) roong
can be used if the building is well ventilated or aluminum should be used if there is containment of corrosive
gases given o by animal manures. Whenever possible, avoid building a second oor, but add more bays to
gain space. is avoids the superstructure needed to support the oor, and it eliminates a possible cave-in to
the rst oor in case of a re.
Livestock barn with a people/animal access back alley.
Adjustable sidewall curtains can replace
enclosed walls and provide ventilation.
Oen people design barns for human comfort, but it is important to
meet the needs of the animals. Decide early on whether the barn is
going to be closed up and insulated and ventilated, or kept open and
cold with natural ventilation. Cold barns with natural air and open to
the south sun, provide very healthy environments. Sidewall curtains
made of fabric (canvas or inatable plastic tubes) can be used in place of
wood sheathing and raised or lowered for ventilation.
Another feature that can be built into animal facilities is a people and/
or animal access alley. is adds a little expense, but can be built along
the back wall of a barn to make it easier to check animals or move them
from pen to pen without disturbing the other animals.
With animal housing, it is important not to make the concrete oors
too smooth. ere should be a minimum of a broom nish, and if
there is a lot of animal trac and scraping activity, the oor needs to be
grooved. It is oen preferable to pour the oor and come back later with
a commercial grooving machine and use a diamond pattern. Trying to
groove at the time of pouring concrete can leave a rough surface because
the concrete cures faster than it can be worked.
Regardless of the type of facility and design, build it with exibility in
mind and with an eye to other future uses. See gures 1 and 2 for pole
barn examples.
Other Considerations
Agricultural buildings should always
be designed with animal, equipment,
and human “trac ow” in mind.
Animals must move in obvious
straight directions. Equipment
needs to be maneuvered easily for
mechanical cleaning and feeding.
Doors need to be wide enough to
accommodate equipment, and eaves
have to be high enough to allow the
passage of tractors with cabs.
Bedded-Pack
Diamond-pattern concrete oor
grooves.
UNH Cooperative Extension • 6
Figure 1. Selected post-frame building widths and congurations. (Post-Frame Building Handbook, NRAES-1, 1997 Revision).
Figure 2. Pole-Type Utility Shedl (Small Farms-Livestock Buildings and Equipment, NRAES - 6/MWPS-27, 1984).
(Idea plan only, check building specications.)
UNH Cooperative Extension • 7
Handy Facts for Construction - Calculations
Area: Rectangle = L (Length) x W (Width)
Triangle = B (Base)
2
x H (Height)
Circle = 3.14 (π) x R
2
(Radius)
Total Board Feet = No. of pieces x T (ickness in inches) x W (Width in inches) x L (Length in feet)
Volume: Cube = L (Length) x W (Width) x H (Height)
Cylinder = 3.14 (π) x R
2
(Radius) x H (Height)
Cone = 3.14 (π)
3
x R
2
(Radius) x H (Height)
Measurements: Cubic Yard = 27 Cubic Feet
Board Foot = 144 Square Inches
Acre = 43,560 Square Feet
Bushel = 1.2445 Cubic Feet
Weights: Water 8.3 lbs/gallon
Grain 40-45 lbs/cubic foot
Hay (baled) 15-20 lbs/cubic foot
Sawdust 12 lbs/cubic foot
Concrete 150 lbs/cubic foot
Concrete - Some Basic Numbers
Water 62 Pounds per Cubic Foot
Water 7.5 Gallons per Cubic Foot
Portland Cement 94 Pounds per Cubic Foot
Sand/Gravel Concrete 112 Pounds per Cubic Foot
Gravel Concrete 148 Pounds per Cubic Foot
Cement/Water Ratio of 0.50 Means About 1 Volume of Water Per 3 1/2 Volume of Mix
Concrete Strength Tensile Strength About 1/8 of Compression Strength
One “Yard” = One Cubic Yard = 1 Yard x 1 Yard x 1 Yard
= 3 Feet x 3 Feet x 3 Feet = 27 Cubic Feet
= 36 Inches x 36 Inches x 36 Inches = 46,656 Cubic Inches
Concrete needed for a dairy barn alley oor that is 5 inches thick and 12 feet wide and 100 feet long =
5/12 x 12 x 100 = 500 cubic feet = 500/27 = 18.5 cubic yards.
About the Authors
John C. Porter, UNH
Cooperative Extension
Professor and Dairy Specialist,
Emeritus and Stanley A. Weeks,
Agricultural Engineering
Consultant, Middle Grove, N.Y.
Updated by John C. Porter,
April 2018.
For More Information
State Oce
Taylor Hall
59 College Rd.
Durham, NH 03824
http://extension.unh.edu
Education Center and
Infoline
1-877-EXT-GROW
(1-877-398-4769)
9 a.m. to 2 p.m. M–F
extension.unh.edu/askunhex-
tension
UNH Cooperative Extension brings information and education into
the communities of the Granite State to help make New Hampshire’s
individuals, businesses, and communities more successful and its natural
resources healthy and productive. For over 100 years, our specialists have
been tailoring contemporary, practical education to regional needs, helping
create a well-informed citizenry while strengthening key economic sectors.
e University of New Hampshire Cooperative Extension is an equal
opportunity educator and employer. University of New Hampshire,
U.S. Department of Agriculture and N.H. counties cooperating.
Visit our website:
extension.unh.edu
Created: June 2009
Updated: April 2018
Additional resources:
• ASABE – American Society of Agricultural and Biological Engineers, 2950 Niles Road, St. Joseph, MI
49085-9659, Phone (269) 429-0300, E-mail: [email protected]g
• DPC – e Dairy Practices Council, 253 Ringwood Road, Apt. I, P.O. Box 432, Freeville, NY 13068
Phone 607-347-4276, E-mail: dairypc@dairypc.org; Website: www.dairypc.org
• Farm and Home Concrete Handbook- NRAES - MWPS-35
• Handbook of Building Plans-MWPS-20
• MidWest Plan Service, 4306D Elings Hall, Iowa State University, Ames, IA 50011-3080,
Phone 515-294-4337, E-mail: m[email protected]u; Website: www.mwps.org
• Guidelines for Milkrooms and Bulk Tank Installations - DPC-41
• Planning a Dairy Complex – 100+ Questions to Ask-DPC-66
• Planning Dairy Free-Stall Barns-DPC-1
• Planning Dairy Tie-Stall Barns-DPC-37
• Post-Frame Building Handbook, NRAES-1, 1997 Revision)
• Small Farms – Livestock Buildings and Equipment, NRAES - 6/MWPS-27, 1984
• Farm Buildings Wiring Handbook - MidWest Plan Service
