TM 5-803-11/AFJMAN 32-10139
should be obtained from the manufacturer to verify
a. Design Considerations.
that a fall onto this surface from the height speci-
(1) Wood Mulch. Wood mulch is relatively inex-
fied by the purchaser results in a g-force rating of
pensive and easy to obtain. Mulch maybe used as a
no more than 200 g's and a HIC value of no more
surface covering in natural areas or as safety sur-
than 1,000. In addition, photos of tested samples
facing in play equipment use zones. It may be pro-
should be obtained from the manufacturer to com-
duced by "chippers" used in tree pruning operations.
pare with the purchased material. A copy of the
It is possible to acquire wood mulch from mainte-
product warranty and an estimate of the antici-
nance staff or tree trimming companies, but it must
pated durability of the material should also be ob-
be free from harmful plants, pesticides, or other
tained.
contaminants. Wood mulch may be produced from
hardwoods or softwoods.
b. Recommended Ages. Wood products may be
used as a safety surface in play areas designed for
(2) Bark Mulch. Bark mulch is bark that has
children ages 2 and older.
been stripped from trees and shredded. It is readily
available from many nurseries or landscape supply
c. Safety Guidelines.
companies.
(1) Variable Impact Attenuation. The impact
(3) Manufactured Wood Chips. Some manufac-
attenuation of different wood products varies, and
turers produce uniform wood chips specifically for
specific test results for materials may not be avail-
use as play area safety surfacing. For these prod-
able. Weather such as rain, high humidity, cold tem-
ucts, ASTM F 1292 testing results may be available
peratures, or freezing conditions may affect impact
from the supplier. This material may be more con-
attenuation. With the passage of time, the materials
sistent in type and quality than wood mulch or bark
may decompose and become pulverized, reducing
mulch.
their impact-attenuating performance.
(4) Additional Selection Considerations.
(2) Installation. Loose-fill surfacing materials
(a) Appearance. Determine whether the sur-
will not be installed over concrete or asphalt sur-
face will look attractive and will complement the
faces.
appearance of play equipment.
(3) Maintenance. The material requires con-
tinuous maintenance, such as leveling, grading, and
provided. For many play areas, subsurface drainage
replenishing, to maintain its impact-attenuating
should be provided. A compacted gravel subsurface
ability. The materials are gradually displaced by
may also be considered.
wind or the playing action of children, reducing the
(c) Installation Requirements. Wood products
thickness required for impact attenuation.'
should be installed over a compacted subgrade cov-
(4) Contaminants. Unless a manufactured ma-
ered with geotextile fabric. Wood products manufac-
terial is purchased, a consistent product that is free
tured for the purpose of playground safety surfacing
from contaminants may be difficult to obtain.
should be installed according to the manufacturer's
(5) Splinters. Chips may be splintery when
instructions at the minimum depth specified in this
first spread.
manual. Surfacing should be contained with a bar-
(6) Microbial Growth. When wet, organic loose-
rier.
fill materials are subject to microbial growth.
(d) Play Activities. Wood products surfacing
(7) Waste and Litter. The material conceals ani-
materials can provide opportunities for manipula-
mal excrement and other trash, such as broken
tive play. Children can explore the surfacing mate-
rials for living organisms and other "finds," such a
puncture and cut. Daily removal of waste and litter
coins, bottle tops, and small plastic toys. The mate-
is required.
rials harbor and conceal various insects that are
(8) Flammability. Wood products are flam-
usually harmless and provide learning opportuni-
mable.
ties for children.
d. Accessibility. The acceptability of wood prod-
(e) Maintenance. It should be determined
ucts as an accessible surface for people with dis-
whether adequate maintenance can be provided to
abilities is still controversial. Some wood products
maintain the surface. Regular maintenance is nec-
may be accessible to wheelchair users when matted
essary to maintain surfacing depth and to prevent
down. Wood products may not be accessible to chil-
the geotextile fabric from becoming a trip hazard.
dren who walk with difficulty or use canes or
(f) Pests. It should be determined if pests will
crutches.
increase the maintenance requirements and reduce
e. Maintenance. The required maintenance level
the material's life span.
is high. Continuous maintenance will be provided to
(g) Manufactured Wood Chips. When specify-
preserve impact attenuation.
ing manufactured uniform wood chips, test results
11-5
Previous Page
