deterioration and preservation final review

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