HOUSING PIH-32
PURDUE UNIVERSITY. COOPERATIVE EXTENSION SERVICE.
WEST LAFAYETTE, INDIANA
Building Materials and Equipment for Swine Facilities
Authors
Vernon M. Meyer, Iowa State University
Gerald R. Bodman, University of Nebraska
William H. Friday, Purdue University
Reviewers
L. Neil Burcham, New Mexico State University
Robert M. Butler, University of Wisconsin
Nevin Wagner, Manheim, Pennsylvania
Producers who have invested in new swine facilities are
often disappointed by the severe deterioration of their facili-
ties after just a few years. Much of the deterioration could have
been prevented if the producer had considered the corrosiveness
of the environment within the facility and the pigs' destructive
nature. These problems are more pronounced in enclosed facilities
but can occur in all types of units. The most rapid deterioration
takes place near the floor because of wetness, chemical corro-
sion, and physical destruction. However, the effects can also be
observed in other parts of the building, especially on unpro-
tected metal. Rapid corrosion of metal is characteristic of
facilities with a poorly designed ventilation system. See Pork
Industry Handbook fact sheet PIH-60, Mechanical Ventilation of
Swine Buildings.
When planning your building, select materials that are
insurable, corrosion-resistant, and durable enough to withstand
the rugged pushing, rubbing and chewing activities of the pigs.
Materials within the building but outside the pens are not as
vulnerable to physical deterioration, but they can have a rela-
tively short life because of corrosion. Materials along alleys
will be subjected to physical abuse from the pigs and from moving
equipment. Therefore, carefully select equipment and materials
regardless of their intended use or location.
Floors
A good, high-quality concrete mix is necessary because
manure acids corrode concrete. Solid floors should be made from a
mix that will yield a 4,000 psi concrete (maximum of 6 gal. of
water per bag of cement). Air entrained concrete should be used
for all installations, especially where the concrete will be sub-
jected to freezing temperatures. An alternative is to place a
lower strength, less expensive concrete as a base and then add a
higher strength concrete over the top as a wear surface. This is
accomplished by placing a steel reinforcement mesh over a rough-
graded layer of concrete and then adding a finish layer of con-
crete. The savings in material cost should be evaluated in light
of possible inconvenience during the placement of layers of con-
crete and higher labor costs.
If slats are to be used, they should be designed for corro-
sion resistance as well as strength. Additional flooring design
details can be found in PIH-53, Flooring for Swine.
Walls
Concrete and wood-frame are both satisfactory for exterior
walls. A choice should be made after considering both construc-
tion and maintenance costs. Consider also the work required to
provide openings in the wall, such as for ventilation.
Concrete is one of the most durable materials for walls that
are subjected to animal and equipment contact. However, concrete
has little thermal insulating value. Where warm interior tempera-
tures are to be maintained, as for a farrowing or nursery facil-
ity, additional insulation is recommended. In cold climates,
insulation is also essential in growing/finishing buildings to
prevent condensation and retain animal heat. In very mild cli-
mates, concrete walls without insulation are satisfactory for
some phases of a hog production facility.
Sandwich panel construction is an effective means of provid-
ing a durable interior and exterior surface and at the same time,
improving the thermal efficiency of the wall. Sandwich panels are
formed by placing a foam board insulation material within the
wall during casting of the concrete. This can be done either with
cast-in-place walls or precast, tilt-up panels.
An alternative that can be used where animals do not have
access to the outside of the building is to erect a concrete wall
and apply a spray-on urethane insulation material on the outside.
The insulation must be painted or otherwise protected to retard
destruction by ultraviolet light from the sun. For added protec-
tion, the foam should be covered with a 1/4-in. layer of spray-on
plaster or gunite concrete. The result is a durable, thermally
efficient, stucco-like wall.
Wood-frame walls may be of conventional stud frame or post
frame construction. In either case a wider range of materials is
available for enclosing the exterior frame. Among the materials
that have been used successfully are ribbed steel or aluminum;
composition boards, such as particle board or hardboard; exterior
plywood; and boards. As with all wall construction, both initial
and maintenance costs, as well as useful life, should be con-
sidered before deciding on the material to use.
With either type of wall, stud or post, thermal insulation
can be added easily. However, appropriate construction plans must
be followed, such as planning stud or girt spacings to accommo-
date standard widths of insulation materials. The range of insu-
lation materials is broad and includes fiberglass blankets, pour
insulation, foam boards and spray-on foams. Regardless of the
insulation material chosen, an interior protective covering is
necessary.
Where walls are exposed only to personnel and will not be
subjected to hog contact or vehicular traffic, the choice of
interior covering materials would include the same materials as
for exterior surfaces.
The potential for both vehicular traffic and animal contact
makes the use of the more durable interior coverings desirable.
For occasional contact, such as along alleys used for hog move-
ment, ribbed sheet metals, plywood, wood boards and composition
boards are good choices. For continual contact, as in pens, the
use of solid coverings hardwood, steel sheets or panels, or
fiberglass-reinforced plastics (FRP) is recommended. Plastic
mouldings used with FRP panels should be located at the pen par-
titions or fastened very securely so as not to give the pigs a
place to start chewing. The FRP material is also available in
roll form in long lengths thereby reducing the number of possible
joints.
On wall areas above the reach of the animals (usually con-
sidered to be about 4 ft.), most common building materials can be
used. However, since sanitation is important in swine buildings,
these lining materials should be nonporous and durable enough to
withstand cleaning with a high-pressure water system.
Ceilings
The main requirements for a ceiling material are cleanabili-
ty and corrosion resistance. Like wall sections above the hog
contact areas, most common building materials can be used.
Since roof trusses are usually spaced 4 ft. on center, the
cost of any additional nailers required for installation of a
particular ceiling product should also be considered as part of
the ceiling cost. Materials such as ribbed metal can be attached
directly to truss chords without additional nailers.
Insulation and Vapor Barriers
Where insulation is to be used, consider the purchase price,
installation cost, required coverings, and thermal effectiveness.
In measuring thermal effectiveness, it is recommended that insu-
lation or ``R'' values as given by the American Society of Heat-
ing, Refrigerating, and Air-Conditioning Engineers (ASHRAE) be
used (Table 1).
The high moisture levels in swine facilities require that
appropriate vapor barriers be used. These are needed to reduce
the movement of water vapor into a wall or ceiling. Allowing
water vapor to move into a wall will cause condensation within
the wall or ceiling assembly. The condensation will result in a
lower R-value and possible destruction of the insulation
material. In general, a 4-6 mil plastic (polyethylene) vapor bar-
rier should be used with all insulation materials because, even
with vinyl-clad foam boards, it is impossible to maintain all
joints in a water vapor-tight condition. In all cases the vapor
barrier should be located on the warm side (inside) of the wall
or ceiling between the interior covering and the insulation. See
PIH-65, Insulation for Swine Housing.
Figure 1 illustrates the procedures of determining the R-
value for a concrete block wall using the data in Table 1. Figure
2 shows how to calculate the R value of a ceiling. Figure 3 shows
winter degree days, and Table 2 recommends minimum insulation
levels for swine buildings.
Mice, other rodents, and birds can seriously damage any type
of insulation. See PIH-107, Controlling Rats and Mice in Swine
Facilities. Use physical barriers to keep rodents out of build-
ings. If ribbed metal is used for inside wall linings, the end
openings of the ribs should be closed to prevent the entrance of
rodents. A good rodent control program is essential since they
Table 2. Recommended minimum insulation levels for swine build-
ings. R values are for building sections.
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Recommended minimum R values
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Modified Supplementally
Winter ``Cold'' environment heated
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degree days Walls Ceiling Walls Ceiling Walls Ceiling
________________________________________________________________
2500 or less 6 6 14 14 22
2501 to 6000 6 6 17 14 25
6001 or more 6 12 25 20 33
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Birds will destroy any exposed insulation. In some cases insula-
tion is consumed directly as food, while in other cases it is
used as a nesting location, a material for nest building, or sim-
ply something to play with to pass the time. Consequently, cover
the insulation and use an effective bird control program.
Pen Partitions
Pen partitions must be durable enough to resist rubbing,
chewing and pushing by pigs and, at the same time, resist the
corrosion of the environment and manure that comes into contact
with them. The choice of materials depends partially on whether
open or solid partitions are used and whether the partition is
permanent or must be movable. Partitions are generally not insu-
lated.
The durability and general corrosion resistance of concrete
makes it an excellent choice for partitions (minimum of 3500 psi;
7 gal. water per bag of cement is recommended). Concrete blocks,
cast-in-place concrete, or precast concrete panels can be used
(Figure 4). As with exterior walls, steel reinforcing bars or
mesh should be a part of all concrete partitions to afford
greater strength and to fasten partitions securely to the floor.
When anchoring equipment to floors or walls, consider using
stainless steel materials.
Woods such as oak and southern yellow pine are fairly dur-
able when used as pen partitions. A key requirement with wood is
to restrict pigs from chewing it. Use tongue-and-grooved planks
or well-matched planks to reduce access to edges where chewing
can start. Softwoods will probably have a useful life of 2 years
or less. Hence, their use should be restricted to temporary
shelters. As with exterior walls, the life of partitions can be
extended by overlaying the basic wood partition with such materi-
als as fiberglass-reinforced plastics, steel sheets, or mesh.
Where wood is in contact with the floor, ground or generally wet
conditions, the use of pressure preservative-treated lumber is
recommended for a longer use life.
Both solid steel sheets and open welded wire mesh have been
used for pen partitions with poor results. The most common steel
panels use vertical rods or tubing. The life of these materials
depends upon how well they can resist corrosion and flexing
because of pushing by the pigs. To maintain partitions and reduce
injury to pigs, all joints must be securely welded and protected
from corrosion. Plain steel panels can be satisfactory if well
protected with a long-lasting coating. The abrasive action of
hogs wears away most post-installation coatings such as paint or
epoxy. Also, once corrosion starts, it tends to work under the
remaining coating and lift it away. Stainless steel is more
expensive but might be worth the additional cost in permanent
structures subjected to intensive use.
Fiberglass panels with vertical bars are now available and
appear durable. Solid plastic planks are available for use where
a solid partition is desired or needed.
Farrowing Stalls
Material used for farrowing stalls includes stainless steel,
aluminum, fiberglass, or galvanized and painted metal. Any metal
near the stall floor is subject to extreme corrosion while parts
of the stall's upper metal is subject to wear from the abrasion
of sows rubbing. Aluminum stalls require nonmetalic insulating
spacers to prevent contact with concrete or dissimilar metals,
and galvanic corrosion.
As with pen partitions, rusting will start quickly at unpro-
tected spots on the steel stalls. A heavy galvanized coat helps
but galvanizing will wear and corrode off in time.
A quality steel farrowing stall will have all welds cleaned
thoroughly, a good prime coat applied and a tough, durable, fin-
ish paint coat applied over it.
The life of all metal equipment will be extended with good
ventilation to keep air in the hog house drier and lower in cor-
rosive gases and by periodic cleaning and painting at the floor
line.
Plastic Pans
When remodeling a farrowing or nursery unit, it is sometimes
more practical to use the existing floor as is, and install plas-
tic pans or trays under the slotted floor to contain the manure.
Manure may be drained into a pipe that collects from each crate
or deck and carries the manure to storage. In some cases a plas-
tic auger can be used to convey the manure to the end of a row of
crates or decks and then drain into storage. Some producers have
indicated that at times, manure sticks to the plastic and must be
cleaned with a high pressure cleaning system at cleanup time. An
alternative is to partially fill the pan with water after each
drain. This improves cleaning ability but requires handling of
greater amounts of liquid manure. Plastic pans should be
installed so that access is provided for hand scraping and pres-
sure washing without having to spray through the floor.
Roof Coverings
The most common covering materials are plain or painted
ribbed aluminum, galvanized or painted steel sheets, and asphalt
shingles. All of these are satisfactory if good quality materials
are purchased and properly applied.
With galvanized steel, the use of sheets bearing a Zinc
Institute, Inc. grade stamp is recommended. Outdoor exposure
studies at The Pennsylvania State University revealed that sheets
with a 2-oz. zinc coating and a ``Seal of Quality'' grade stamp
required 15 years of exposure before the first signs of rust.
Sheets with a 11/4-oz. zinc coating began to rust after 7 years.
Sheets with less zinc per square foot than these industry stan-
dards are available at lower cost and will have a correspondingly
shorter life before the first signs of rust. It is not possible
to determine the amount of zinc coating by visual inspection.
Even where factory applied finishes are used, the heavier zinc
coatings should be used.
Galvanized and painted steel is sold on the basis of thick-
ness or gage. Gages most commonly available are 28 and 29. Lower
gage numbers indicate greater thickness. A choice should include
consideration of required roof design loads in the area and the
load-carrying capacity of the roofing sheets. Manufacturers'
literature and local codes can provide the required information.
In selecting aluminum roofing sheets the ease of installa-
tion should be considered. The use of high-strength alloy sheets
of less thickness might be a disadvantage since their greater
brittleness tends to cause them to split rather than dent if hit
too hard or stepped on improperly. Avoid the use of extremely
long sheets because of changes in length with variations in tem-
perature. This results in tearing out of nail holes, or bending
or extraction of nails or other fasteners. Fewer roof-leakage
problems are generally experienced where the length of roofing
sheets is kept to 24 ft. or less.
To prevent corrosion of metal roofing through galvanic
action, it is imperative that the correct fasteners be used with
each kind of metal. Also, galvanized and aluminum sheets should
not be placed in contact with each other. Where it is necessary
to mix galvanized and aluminum products, they should be separated
by a nonmetallic intermediate material.
When installing asphalt shingles, use at least 235-lb. shin-
gles with self-sealing tabs.
Regardless of the roofing material used, the limitations of
its use as related to roof slope should be recognized.
Plumbing
PVC or similar plastic pipe is probably the most suitable
for a swine building environment. Because of the corrosive atmos-
phere within swine facilities, metal pipe should be used with
caution. Copper pipe usually has a short life when exposed in a
swine building. If galvanized or black iron pipe is used, some
type of coating should be applied at the threads since this part
of the pipe is most subject to deterioration and failure.
In warm facilities, plumbing can be run overhead to reduce
contact with animals and manure. Although overhead pipes can be
used in cold buildings, such placement requires electrical heat
tape and pipe insulation to prevent freezing. Consequently, in
cold facilities underground plumbing is recommended. Where pipes
are brought to the surface, they can be run through a large-
diameter plastic pipe to reduce corrosion and provide easier
maintenance.
In cold facilities, built-in heating units are suggested
where cup waterers are used. Nipple waterers (Table 3) generally
do not require additional freeze protection beyond that provided
on the pipe up to the nipple. In all cases, a durable high-
strength cover is required over pipe insulation and heat tape to
reduce damage by pigs and reduce the potential of electrocution
of pigs. Adequate grounding of all electrical equipment is a
MUST. Good-quality waterers should be selected to reduce mainte-
nance costs, extend the use life of the waterers, and reduce
water usage and manure hauling costs resulting from leaking
valves.
Table 3. Planning guide, nipple waterers.*
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Sow
Pig weight, lb. and
_____________________________
Item < 12 12-3030-7575-100100-240boar
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Height, in. 4-6 6-12 12-1818-24 24-30 30-36
Pigs/nipple litter 10 10 12-15 12-15 12-15
Min. flow
rates, quarts
per min. 0.2 0.2 0.4 0.5 0.67 1.0
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* Install at least two waterers per pen. Locate waterers 14"
apart for nursery pigs; 24" for larger pigs. This distance may
be reduced some if the nipples are angled away from each
other.
Electrical
This may be the most critical component of a swine building
since corrosion can create conditions that increase the risk of
fire and electrical shock. Electrical materials installed inside
a swine building should be designed for damp or wet locations.
Thin-wall metal conduit has a short life and should not be used.
Fittings, outlet boxes and switches not designed for waterproof
locations may create an unsafe condition after several years. If
conduit is used, it should be plastic. Type UF cable with water-
proof fittings is another option. If at all possible, locate the
entrance box in a dry annex of the office room to avoid rapid
corrosion. Only surface-mount boxes should be used, especially on
outside walls. See PIH-110, Electrical Wiring for Swine Build-
ings. In cold climates, problems can be reduced if all conduit is
installed within the warm part of the building. When conduit
extends from the warm building up into the cold loft or attic,
condensation can occur and the resulting moisture can move back
to a fitting and cause corrosion or electrical faults. If a posi-
tive pressure ventilation system is used, be sure that no moist,
corrosive air can be pushed into electrical boxes.
As noted in the discussion on plumbing, grounding of all
electrical equipment is a MUST. This applies to all switches,
receptacles and appliances since wet floors increase the con-
tinual threat of shock and possible electrocution of both person-
nel and animals. All electrical equipment and wiring should be
installed in accordance with the National Electrical Code. Check
with your electrician or power supplier.
Feeders
A low-quality feeder (Table 4) will not last long in a hog
house. The increased moisture level near the floor speeds up cor-
rosion. The activity of the pigs causes rapid wear. The upper
part of the feeder may last more than 10 years, but this helps
little if the bottom has failed.
When purchasing a metal feeder, look for stainless steel or
cast iron bottoms. Wood feeders can be improved by covering the
wooden trough with a more durable material such as fiberglass or
metal. Plastic feeders resist corrosion and appear durable.
As with plumbing and electrical lines, the running of feed
conveyance equipment through a ceiling should be minimized to
reduce the risk of moisture condensation and the loss of heat.
Ease of adjustment in a feeder is as important as durabil-
ity. If a feeder cannot be easily adjusted to prevent feed waste,
it can easily cost its owner many times its replacement value.
Feeders with flat bottoms reduce shelter areas for rodents and
are recommended.
Table 4. Feeder space.
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Pig weight, lb. Pigs/feeder space
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12-15 2
25-50 3
50-120 4
120-240 4-5
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o
Reference to products in this publication is not intended to be
an endorsement to the exclusion of others that might be similar.
Persons using such products assume responsibility for their use
in accordance with current label directions of the manufacturer.
REV 12/88 (5M)
______________________________________________
Cooperative Extension Work in Agriculture and Home Economics,
State of Indiana, Purdue University and U.S. Department of Agri-
culture Cooperating. H.A. Wadsworth, Director, West Lafayette,
IN. Issued in furtherance of the Acts of May 8 and June 30, 1914.
It is the policy of the Cooperative Extension Service of Purdue
University that all persons shall have equal opportunity and
access to our programs and facilities.
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