TQL 4 Residential Timber Decks - Ozbuild Materials

1 Timber Queensland Limited technical Data Sheet 4 - Residential Timber DecksRevised March 2006 - Page 1 IntroductionThis data sheet contains TQ s recommendations for residentialtimber Decks , verandahs, patios etc which are exposed to theweather. It covers the most common Timber species and alternative sizes, spans and stress grades refer to AS 1684 Residential Timber -framed construction. For commercial andindustrial Decks , refer to technical Data Sheet 7. For Decks closeto the ground ( framing less than 400 mm above ground),refer to technical Data Sheet 13. For Timber handrails andbalustrades, refer technical Data Sheet SelectionPosts in contact with the ground shall be either preservative treatedpine or In-ground Durability Class 1 hardwood, with any sapwoodpreservative treated. Some In-ground Durability Class 2hardwoods and cypress (refer Table 1) may be used for in-groundapplications if they can be easily replaced should decay and deck framing above ground shall be either cypress,preservative treated pine or Above Ground Durability Class 1hardwood.

2 Hardwood decking boards and deck framingcontaining sapwood must be preservative treatment for posts in the ground and framing onthe ground, shall be to hazard level H5. Preservative treatmentfor framing more than 150 mm above ground shall be framing may contain limited amounts of sapwood ( width of face or edge) provided the sapwood does notoccur at joints or fixing decking shall be Grade No. 1 in accordance with AS in cypress decking boards shall face downward and bebelow or as close as possible to any eaves or roof decking shall be standard (medium feature) grade orselect grade in accordance with AS 2796. Select grade decking isrecommended in fully weather exposed situations. Softwooddecking shall comply with the grading rules for Pine boards shall be seasoned to the requirements of theapplicable Australian Standard ( Hardwood 10% to 18%,Softwood 10% to 15%).

3 Note: TQL recommends a maximum MC of 15% for residentialdecking.* See Note 1 timbers should only be used for in-ground applications if they can beeasily replaced if degrade CCA treated Timber shall not be used for domestic decking boardsTable 1 Species SelectionSpeciesSpeciesSpeciesSpeciesSpe ciesPosts in GroundPosts in GroundPosts in GroundPosts in GroundPosts in GroundPost and FramingPost and FramingPost and FramingPost and FramingPost and FramingDeckingDeckingDeckingDeckingDecki ng Above Ground Above Ground Above Ground Above Ground Above GroundPRESERVATIVETREATED PINE H5 Treatment H3 Treatment H3 Treatment(Carribean, Hoop,(See Note 2)Radiata, Slash)MIXED OPEN FORESTHARDWOODS(See Note 1) (QLD, Nthn. NSW)BALAU Yellow BELIAN BLACKBUTT(See Note 1) CYPRESS(Sapwood Free)* GUM Forest Red GUM Grey GUM Spotted(See Note 1) IRONBARK Red or Grey KWILA (MERBAU) MAHOGANY Red(See Note 1) MAHOGANY White MESSMATE Gympie TALLOWWOOD TURPENTINE Residential Timber Decks Recommended Practice / March 2006 Recommended Practice / March 2006 Recommended Practice / March 2006 Recommended Practice / March 2006 Recommended Practice / March 2006 Issued by: Timber Queensland LimitedIssued by: Timber Queensland LimitedIssued by: Timber Queensland LimitedIssued by: Timber Queensland LimitedIssued by.

4 Timber Queensland LimitedTechnical Data Sheet4 Page 2 - Revised March 2006 Timber Queensland Limited technical Data Sheet 4 - Residential Timber Decks Table 3 Bearers Floor Load Width (mm) (Length of joists supported) Floor Load Width (mm) (Length of joists supported) Floor Load Width (mm) (Length of joists supported) Floor Load Width (mm) (Length of joists supported) Floor Load Width (mm) (Length of joists supported)180018001800180018002400240024 0024002400300030003000300030003600360036 0036003600180018001800180018002400240024 0024002400300030003000300030003600360036 0036003600 Maximum Bearer Span (mm) Maximum Bearer Span (mm) Maximum Bearer Span (mm) Maximum Bearer Span (mm) Maximum Bearer Span (mm)Member SizeMember SizeMember SizeMember SizeMember Size (mm) (mm) (mm) (mm) (mm)

5 Single SpanSingle SpanSingle SpanSingle SpanSingle Span Continuous Span Continuous Span Continuous Span Continuous Span Continuous Span Unseasoned Unseasoned Unseasoned Unseasoned Unseasoned100 x 751000 NSNSNS1000 NSNSNS Cypress, F5 Cypress, F5 Cypress, F5 Cypress, F5 Cypress, F52/100 x 5013001100900NS13001100900900125 x 751300110010001100130011001000NS2/125 x 5016001400130011001600140013001100150 x 75160013001200135016001300120011002/150 x 5019501650150013001950165015001350175 x 75180016001400130018001600140013002/175 x 5022001900170016002200190017001600200 x 75210018001600150021001800160015002/200 x 5026002200200018002600220020001800 Seasoned Seasoned Seasoned Seasoned Seasoned140 x 45130011001000900130011001000900 T T T T Treated Preated Preated Preated Preated Pine, F7ine, F7ine, F7ine, F7ine.

6 F72/140 x 35170015001300120017001500130012002/140 x 4520001700150014002000170015001400190 x 45175015001350120017501500135012002/190 x 35240020001800160024002000180016002/190 x 4527002300210019002700230021001900240 x 45220019001700155022001900170015502/240 x 35300026002300210030002600230021002/240 x 4534002900260024003400290026002400 Unseasoned Unseasoned Unseasoned Unseasoned Unseasoned100 x 7517001400130011001700140013001100 Hardwood, F14 Hardwood, F14 Hardwood, F14 Hardwood, F14 Hardwood, F142/100 x 5019001700160014002100180016001400125 x 75210018001600150021001800160015002/125 x 5024002200200018002600230020001800150 x 75250022001900180025002200190018002/150 x 5029002600240022003100270024002200175 x 75290026002300210029002600230021002/175 x 5033003000280026003700320028002600200 x 75340029002600240034002900260024002/200 x 5037003400320030004200360032003000 Notes:1.

7 Bearers to support floor loads only. Posts supporting roof to be directly over deck Maximum cantilever can be 25% of allowable span provided the actual backspan is at least twice the actual Sizes greater than 200 mm deep may not be readily For other stress grades and sizes refer to AS1684 Residential Timber -framed 2 Timber Posts Supporting Roof and/or Floor LoadsFloor AreaFloor AreaFloor AreaFloor AreaFloor AreaSupported (m )Supported (m )Supported (m )Supported (m )Supported (m )5555510101010101515151515 Roof AreaRoof AreaRoof AreaRoof AreaRoof AreaSupported (m )Supported (m )Supported (m )Supported (m )Supported (m )000005555510101010102020202020000005555 5101010101020202020200000055555101010101 02020202020 Member SizeMember SizeMember SizeMember SizeMember SizeMaximum PMaximum PMaximum PMaximum PMaximum Post Height (mm)ost Height (mm)

8 Ost Height (mm)ost Height (mm)ost Height (mm)Sheet75 x 7548003800270019001900170016001400 NSNSNSNSRoof100 x 10048004300300021002100200019001700 NSNSNSNSU nseasonedUnseasonedUnseasonedUnseasonedU nseasonedCypress, F5 Cypress, F5 Cypress, F5 Cypress, F5 Cypress, F5 Tile75 x 754800260018001200180016001300900 NSNSNSNSRoof100 x 1004800460032002300330029002600210015001 300 NSNSS heet70 x 7048004100290020001900180017001500 NSNSNSNS Seasoned Seasoned Seasoned Seasoned SeasonedRoof90 x 9048004800480034003200300029002600160015 0014001300 TTTTT reated Preated Preated Preated Preated Pine,ine,ine,ine,ine,F7F7F7F7F 7 Tile70 x 7048002900210014001900170015001100 NSNSNSNSRoof90 x 9048004800340024003200280026002200160014 001300 NSSheet75 x 7548004800370026002600250023002100150014 0014001300 UnseasonedUnseasonedUnseasonedUnseasoned UnseasonedRoof100 x 1004800480048004600460043004100370026002 60025002400 Hardwood, Hardwood, Hardwood, Hardwood, Hardwood.

9 F14F14F14F14F 1 4 Tile75 x 7548003700260018002600230021001700150014 0013001100 Roof100 x 1004800480037002600460040003600300026002 50024002200 Sheet100 dia21002000190018001500140013001200900 NSNSNSRoof125 dia3600340032002900250024002400230020002 00019001800 TTTTT reated Preated Preated Preated Preated Pineineineineine150 dia4800480048004800450043004200400036003 60035003400 Rounds F8 Rounds F8 Rounds F8 Rounds F8 Rounds F8 Tile100 dia2100190017001400140013001200900 NSNSNSNSRoof125 dia3600320029002500250024002200200020001 90018001600150 dia4800480048004400450042004000360036003 50034003100 Timber Queensland Limited technical Data Sheet 4 - Residential Timber DecksRevised March 2006 - Page 3 Termite ProtectionPhysical and/or Chemical barriers must be provided to protect thedeck and to ensure termites do not bypass protection systems toadjacent structures.

10 Termite barriers must be designed so thatthey can be readily inspected and adequate termite protection is not provided to Decks , theyshall be completely isolated from any adjacent DesignTables 2, 3 and 4 list sizes for posts, bearers and joists, for commonmember spacings and commonly used Timber stress following tolerances apply:- Unseasoned Cypress+ 2 mm - 4 mm Seasoned Pine+ 2 mm - 0 mm Unseasoned Hardwood+ 3 mm - 3 sizes for bearers and joists do not allow for roof loads ( supporting roof to be continuous to the ground or bepositioned directly over deck supports) and are suitable for amaximum decking mass of 20 kg/m .For alternative sizes, spans and stress grades or for memberssupporting roof loads, refer to AS 1684 Residential Decks to HouseLedgers shall be a minimum 90 x 45 mm treated pine, hardwoodor cypress, fixed to house framing (studs, joists or bearers) with12 mm dia.