Plywood Both decorative and structural Sheet product suitable for panelling structural flooring bracing webs in composite beams Standard size sheet 2700  1200 mm 2400  1200 mm 1800  1200 mm Photo: Plywood Association Australia Aboriginal Studies building, Curtin University, Perth, WA Photo: Geoff Boughton

Manufacture Photo: Geoff Boughton Made by gluing and pressing thin laminates together to form a sheet Grain in laminates in alternate directions - strength in two directions Final plywood sheet Seven laminates prior to gluing and pressing face grain direction grain in face laminate

Uses Panels (decorative, acoustic or bracing) Sheets - plate bending (flooring, formwork) Webs (I-beams, box beams) Structural or appearance function for all of the above

Colour-matched ceiling panels National wine Centre, Adelaide Photo: Trevor Fox Australian Timber Design: 11

Chairs also feature plywood. Sydney Opera House Photo: Geoff Boughton Extensive use of wall and ceiling panels with decorative and acoustic functions. Chairs also feature plywood.

Decorative plywood with structural function Exhibition buildings, Homebush, Sydney Photos: Geoff Boughton Observation deck, Sydney Showgrounds Photos: Geoff Boughton Decorative panels also have bracing function Handrails are structural

Sheets Acts in minor axis bending in Flooring Can span in two directions High strength material can be used for low profile floors Photo: Plywood Association Australia

Sheets Formwork – requires: Good surface finish Water tight construction Glues must be water resistant Strength and stiffness to prevent failure and sagging under wet concrete loads Photo: Geoff Boughton Photo: Geoff Boughton

Box section portal frame Webs and gussets Box section portal frame C-section purlin Photo: Geoff Boughton Photo: Geoff Boughton High in-plane shear strength makes plywood ideal for webs and gussets in composite beams and portal frames

Plywood gussets on Glulam portal Photo: Geoff Boughton Photo: Keith Crews Plywood gussets on Glulam portal Salvation Army Church, Dural, NSW Photo: Greg Nolan Plywood gussets on box beam portals Plywood as wind bracing

Veneer Quality Veneer Quality A Veneer Quality S Veneer Quality B Decorative Quality A Veneer Quality A High quality appearance grade Suitable for clear finishing Specified when surface appearance critical Veneer Quality S Appearance grade Natural characteristics decorative feature Veneer Quality B Appearance grade suitable for high quality paint finish Veneer Quality C Non-appearance grade with solid (filled) surface Suitable for flooring that will have decorative overlay Veneer Quality D Non-appearance grade with open imperfections Suitable for structural plywood bracing Sports stadium floor Photo: Plywood Association Australia

Service classes Type A bond Type B bond Type C & D bonds For exterior plywood used in conditions of full exposure, Interior plywood used in wet or damp conditions eg around sinks, vanity units, laundry tubs. Type B bond Suitable for applications involving up to 2 years exposure to weather eg concrete formwork Used permanently in semi exposed applications eg exterior door skins Type C & D bonds Internal, dry conditions only Non-structural

Properties of Plywood Low variability in properties - reliable Usually graded as F-grade products (see Table 5.1 in AS1720.1 for plywood properties) Specify: Stress grade Thickness and number of plies Glues – interior, exterior, marine Quality of face finishes Species used on face and other plies