week 7 Flashcards
(22 cards)
What is embodied energy in building materials?
Embodied energy is the total energy required to extract, process, transport, and manufacture a building material, measured over its lifecycle.
List the following materials from most sustainable to least based on embodied energy (most sustainable = lowest embodied energy):
Air dried sawn hardwood (lowest)
Kiln dried sawn hardwood
Clay bricks
In situ concrete
Concrete blocks
Cement
Galvanised steel
Aluminium (highest)
Which hardwood timber is lighter than a softwood species listed?
Balsa, although a hardwood, is lighter than softwoods like Douglas Fir and Oregon.
What are two main methods of timber seasoning, and how do they differ?
Air-drying: Natural drying through stacking in open air; slower, less energy use.
Kiln-drying: Uses heated chambers for faster, controlled drying; suitable for precise moisture control.
What are the benefits of seasoning timber before use in construction?
Reduces weight
Improves strength and hardness
Increases stability (less shrinkage)
Improves resistance to insects and fungi
Enhances joinery and gluing capability
What are key indicators of good-quality timber?
Taken from heartwood, straight and close fibres
Uniform colour and sweet smell
Produces clear ringing sound when struck
Free of shakes, excessive knots, or decay
Smooth, bright surface when planed
What are common support methods for timber ground floors?
Timber ground floors are typically supported by brick piers, steel posts, or timber stumps, each requiring design in accordance with AS 1684.2.
What is the maximum height for a standard 230mm brick pier without engineering certification?
1.0 metre or 11 brick courses. Heights above this require increased base size or structural certification.
Why must steel posts be braced and treated at the base?
Steel posts are often slender and must be braced for stability; bases should be treated with rust-inhibiting coatings before being embedded in concrete.
What is the key durability requirement for timber stumps?
Timber stumps must be made of Class 1 durable timber or CCA-treated timber and embedded at least 450mm or 30% of above-ground height, whichever is greater.
What are the two main considerations for timber ground floor design?
Ensuring adequate subfloor ventilation to prevent dampness, and applying termite protection to avoid structural damage.
How are bearers and joists connected in timber floor systems?
Joists are fixed to bearers, which span between supports; bearers must be fixed to posts or piers with enough bearing and lateral restraint.
What is the minimum joist bearing and spacing rule per AS 1684.2?
Joist ends must bear at least 30mm on supports, and spacing is based on flooring span capacity, typically 450mm or 600mm
What makes timber ground floors ideal for residential buildings?
They are lightweight, simple to construct, and cost-effective, especially on sloped sites or where ventilation and access under the floor is needed.
What types of boards and panels are used in building construction?
Flat pressed particleboard, plywood, block-board (for exterior use), and hardboard.
What is the difference between weaker and stronger board products?
Weaker products are used for thermal or sound insulation; stronger ones are used for floor or roof decking.
How is plywood constructed?
Plywood is made by bonding two or more plies together with the grains of adjacent layers at right angles.
What are exterior grade plywoods typically used for?
Exterior grade plywood is used for formwork, flush doors, hoarding, soffits, pelmets, and cladding.
What is block-board, and how is it different from laminboard?
Block-board (or battenboard) has core strips over 80mm wide; laminboard has core strips not exceeding 7mm.
What interior applications is block-board suitable for?
Cabinet making, partitioning, built-in cupboards, wardrobe doors, shelving, tabletops, and workbenches.
What types of boards fall under particleboards?
Chipboard and hardboard
What are the common uses of particleboards?
Furniture, built-in fitments, partitions, roof decking, and formwork.
