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 Aboriginal Studies building,
Curtin University, Perth, WAPhoto: Geoff Boughton
Photo: Plywood Association Australia
Manufacture
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
Photo: Geoff Boughton
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
Panels
Colour-matched ceiling panels
National wine Centre, Adelaide Photo: Trevor Fox Australian Timber Design: 11
Extensive use of wall and ceiling panels with decorative and acoustic functions.Chairs also feature plywood.
Sydney Opera HousePhoto: Geoff Boughton
Decorative plywood with structural function
Handrails are structuralDecorative panels also have
bracing function
Exhibition buildings, Homebush, Sydney
Photos: Geoff BoughtonObservation deck, Sydney Showgrounds
Photos: Geoff Boughton
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
Webs and gussets
High in-plane shear strength makes plywood ideal for webs and gussets in composite beams and portal frames
C-section purlin
Box section portal frame
Photo: Geoff BoughtonPhoto: Geoff Boughton
Plywood as wind bracing
Plywood gussets on Glulam portal
Plywood gussets on box beam portals
Salvation Army Church, Dural, NSW
Photo: Greg Nolan
Photo: Geoff Boughton Photo: Keith Crews
Veneer Quality
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
Decorative Quality A
Service classes
Type A bond• 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
Top Related