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AWPA standards
help us define where the product will be used, how it will be used, and it what geographical areas is should be used in
what is wood?
biological material, hygroscopic, heterogenous, and anisotropic
goal of preservation?
to extend the service life of the product
advantages of wood use
carbon sequestration, strong material, sustainable, renewable
why do we need to know wood anatomy
to help us know how to treat wood to the best of our abilities; we need to know how to treat each species differently
hardwood second
sapwood first
wood physics
properties we cannot change, ie hygroscopicity and density
mechanical testing
bending test most important; top holds compression, bottom holds tension, middle holds shear
fungi body
hypha < hyphae < mycelium < thallus (fruiting body)
fungi
causes most damage due to it being cosmopolitain
fungal reproduction
sexual or asexual; overall decision based off environment
sexual reproduction
better, needs partner; meiosis
asexual reproduction
easier, less good; spores
fungi characteristics
eukaryotic (protected nucleus), dikaryotic (two nuclei)
ascomycota
soft rot; most OVERALL fungi species
basidomycota
white rot and brown rot; most WOOD DECAY species
fungi metabolism
enzymes break down cellulose (lock-key/enzyme-substrate)
conditions for fungal growth
nutrients (wood), oxygen, temperature, moisture, pH
substrate vicinity
food for fungi needs to be close enough for it to attack; if it's too far, they won't eat
brown rot
decay cellulose and hemicellulose, leaves lignin; cubical shape, brown color, attacks softwoods mainly
white rot
decay all components of wood, starts with lignin; moist, spongy, white, attacks hardwood and softwoods
brown rot and white rot testing
8-12 weeks
soft rot
high MC, initially superficial decay; hardwoods mainly
soft rot testing
1 year test
all rots
affect mechanical properties
control of fungi
inhibit growth conditions; make food toxic, spray logs with water, to prohibit oxygen, chemical treatments, biological control, design of buildings
termites
social insect, pests and beneficial, in hotter areas, subterranean (lower termites)
pest qualities of termites
cost millions in damage annually
beneficial qualities of termites
nutrient cycling
coptotermes
invasive, in costal areas; smaller colonies, eat everything, localized
reticulitermes
native, everywhere; eat EW leave LW, more spread out
insects
beetles, termites, carpenter bees/ants, wasps
termite metabolism
mechanical breakdown (mandibles), midgut (endogenous cellulases), hindgut (exogenous cellulases), excretion (building material, fed to other termites)
worker termites
take care of all other termites
beetles
not social, pre and post harvest
pre harvest beetles
pre seasoning, bark beetles
post harvest beetles
post seasoning, ALBOW, ambrosia beetles
TOP A TOW
type-of-product, age, type-of-wood
age
less than 10 years, more than 10 years
TOW
type of wood; softwood or hardwood
TOP
type of product; furniture, plywood, etc
ALBOW
Anobiidae, Lyctidae, Bostrichidae, Old Home Bores, Weevils
marine bores
mollusk (shipworms, pholads) and crustaceans (limnoria); like warm water
control of marine bores
mechanical barriers, harsh teratments
bacteria
slow, super wet, superficial attack; absorbs more product than unaffected wood
carpenter bees, carpenter ants, wasps
its a home, not food
abiotic ants
non living; weathering, chemicals, heat (fire), mechanical wear (cutting board, stairs)
timber structure
inspections needed, historical buildings, timber bridge; failures due to improper piling, water penetration, lack of inspection and remedial treatments
types of treatments
oil borne, water borne, borates
AWPA categories
risk zones, material or species; creates for us to reference
plant layout
cylinders, heat source, in-feed and out-feed, vacuum system, pressure system, tankage, process control system, effluent control system, quality control system
retention
how much preservative went inside the wood
penetration
depth of preservative within the wood
treatment processes
full-cell process (bethel), empty cell process (rueping and lowry)
full cell process
has initial vacuum to remove all air; treatment leaves lumen full of preservative
empty cell process
no initial vacuum, but final vacuum to remove excess preservative; treatment leaves lumen coated
remedial treatment
post-treatment, in-service; field applied, supplemental
labs
E10, E22, E1, pressure treatments, field tests
E10
weight loss, 8-12 weeks, cube shaped sample
E22
strength loss, vacuum at end to remove excess water and to kill fungi
plant layout and design
cylinders or retorts, heat source, in-feed and out-feed systems, vacuum system, pressure system, tankage, process control system, effluent control system, quality control system
types of tankage storage
storage tanks (concentrates, carriers), working tank, mixing tanks
material arrival
comes by truck or railroad and is mechanically off-loaded, computer inventoried and stored
untreated materials
prepared for treatment as either round bundles or square packages
process control systems
gauge vs automated; computer controlled systems monitor and control pressure, temperature, vacuum, fluid injection rate and volume
vacuum pumps
control all movement of fluids such as water, preservative, and blowback in the cylinder
pressure system
air compressors or pressure pumps, multistage centrifugal
heating systems
direct or indirect, boiler to plant to produce steam; gas-fired, hogged fuel, combo system, co-generation
direct heating
easy but large effluent
indirect heating
minimize effluent, less water consumption, coil corrosion
in-feed, out-feed systems
tracked tram cars, fork lifts, loaders
treating cylinders
4-10 ft diameter, operate up to 200 psi (1400 kPa), insulated, up to 175 feet long, mounted with stand expansion and contraction
effluent control systems
filters, catch basins, ponds, aeration lagoons, dripskirts and sumps, dikes, aromatic poly-carbon inorganic waste separators; concrete bunkers around all tanks collect any potential leaks or rain-water run-off, clay lined and aerated rain-water collection ponds remove an contaminants from collected rain water
quality control
effectiveness of a wood preservative depends on retention and penetration
retention
how much preservative went inside the wood (lbs/ft^3)
penetration
depth of preservative in the wood
new plants
hydraulic door locks, ground barriers, computer operated; concrete or asphalt paved, covered with roofs to control rain water run-off, concrete drip pad, large heated or controlled ventilated sheds used
why do we preserve wood
allows us to conserve timber and increase the service life, therefore forests are conserved by preserving wood
major concerns in wood preservation
environmental concerns (air and water quality standards), effect of treated wood on man and nontarget organisms, the energy crisis (oil and oil-based preservative systems)
history of wood preservation
began in the BCE's with natural oils and other materials, took force with the beginning of railroads
requirements for chemicals in preservation
any chemical that claims to be a biocide must be registered with the EPA and within the state it is sold
qualities of an ideal preservative
toxic to good range of woo-inhabiting organisms, high degree of performance (low volatility, resistance to leaching, chemical stability), ability to penetrate in wood readily, hydrophobic, noncorrosive to metals, safe to handle, low environmental impact, favorable economics
effectiveness of preservative treatment
depends on chemical formula, method of application, proportion of sapwood to heartwood, MC, retention, penetration, distribution of chemical in the wood
treated products
seasoned building materials, utility poles/fence posts/rails, structural members, structures and dwellings, crop containers, lawn furniture, playground equipment, garden/landscape timbers, log homes, transportation vehicles (truck beds and support structures)
effect of wood characteristics on preservation
sapwood accepts preservatives more readily than heartwood, softwoods can be treated more uniformly than hardwood; treatment by pressure is usually required for wood exposed to high risk of fungi, insects, or marine borer attack
classification of pesticides
general use v restricted use
general use classification
less hazardous; copper naphthenate, copper 8
restricted use classification
only those who are trained and licensed may purchase or use these preservatives; creosote, pentachlorophenol (penta), inorganic aresenicals
heavy duty wood preservatives
chromated arsenicals, creosote, penta (ongoing discussion and regulations by EPA)
treatments used in residential lumber and timber market
alkaline copper quatenary (ACQ), borates, copper azole, copper naphthalene, polymeric betaine
oilborne systems
creosote, penta, copper naphthalene, copper 8, TBTO
waterborne systems
ACQ, copper azole, borates, ACZA, CCB, etc
industrial use of preservatives
mostly exterior exposure, big three (creosote, penta, CCA), restrictions threatened
residential use of preservatives
outdoor and indoor exposure, waterborne (CCA); hesitations due to public perception
wood treatments/preservatives
any substance or material that, when applied to wood, extends the useful service life of the wood product; chemicals, applied as solids, liquids, or gases
toxic to wood-degrading organisms
wood treatments or preservatives need to be
two types of wood treatements
pressure treatment or remedial treatment
remedial treatments
distribution of preservative into areas of a structure no protected by the original pressure treatment; in-place, field-applied, supplemental, non-pressure preservatives, superficial protection
remedial treatments examples
paste/bandages, fumigants, liquids, solid rods; in-place treatments : envelope, diffusion
envelope treatments
brush or spray (wood surfaces), biocides or biocides formulated with water repellants