Flashcards in Wood Treatement Deck (17)
redwood: naturally occurring resins =
resistant to moisture/insects.
common sources of damage:
fungi when moisture,
preservatives: applied by
most effective preservative applicaiton
distillate of coal tar.
protects against insects.
ex. protect railroad ties, marine timbers, roadway guard posts.
not used in building construction.
pentachlorophenol (aka penta) is an example of this type of preservative:
pentachlorophenol (aka penta) uses:
fresh water pilings/
pentachlorophenol (aka penta) typ. not used on building applications,
glulam long spans in arenas/pools.
most common preservatives in building.
protection against termites and decay.
advantages of this preservative: clean, odorless, non staining.
leave wood paintable.
examples of this preservative type:
ammoniacal copper quaternary (ACQ)
*aka alkaline copper quat.
sodium borate (SBX)
chromated copper arsenate (CCA)
no longer used,
ACQ and copper azole,
more corrosive than CCA,
fasteners to spec for use w ACQ and copper azole.
304 or 316 stainless steel,
or hot-dip galvanized w min G90 coating.
problem w preservatives w borates:
leach when moisture.
use protected, not at ground.