Performance characteristics of woods Flashcards
True or false : the cost of wood and timber decreases wth the amount of processing
False - it increases
What is meant by rough sawn wood?
wood comes direct from seasoning and has rough surfaces produced during initial conversion
cheapest stock form
What is meant by planed square edge?
wood has online edge planed accurate , rest are rough sawn
What is meant by planed all round?
wood has sides and edges that are all planed square, straight and level leaving smooth finish
most expensive stock form as it is ready to use
What is meant by natural wood?
comes from trees and is available only at maximum width of tree
What is meant by manufactured boards?
man made and produced in large sheets
What is meant by mouldings?
pre-made mouldings such as skirting boards or wooden trims are readily available in standard lengths
True or false? wood is stronger in the direction of the grain and weaker across the grain
true
When is the best time to fell wood and why?
winter to reduce time taken to Eason wood as they grow less , have less sap and therefore obtain the least moisture
What is air seasoning?
traditional and inexpensive
wood is stuck in shelter outside protected from rain
air circulate between plans to remove excess moisture
slow process (up to a year)
wood used for outdoor products
What is kiln seasoning?
expensive, using controlled temperature and humidity levels
wood stacked on trolleys
initially steamed in kiln and becomes hotter and drier
quick process (few weeks)
indoor products
Why is wood seasoned?
greater immunity from decay
increases strength and stability
helps preservatives penetrate
makes wood less corrosive to metals
What does the toxicity of wood depend on?
species: both wood dust and sap can be a hazard
