2012 - ISSUE 1 - Timber Truss Solutions

1 2012 - ISSUE 1 VIC(03) 8795 8888 NSW (02) 8525 8000 QLD (07) 3861 2100 SA (08) 8234 1326 WA(08) 6218 5945 NZ(09) 274 7109 MALAYSIA(603) 3176 74732 TABLE OF CONTENTSPosiStrut floor Truss SystemIntroductionAdvantagesDefinitionsF loor StiffnessFloor LoadingResidential Load span Charts for Bottom Chord SupportResidential Load span Charts for Top Chord SupportCommercial Load span Charts for Bottom Chord SupportSupporting StructureHandling and StorageSet Out and PlacementTrimming On SiteSupporting External WallsSupported Non-Load Bearing WallsSupport DetailsFixing and ConnectionsStrongbacksStair OpeningsCantileversBracingMechanical ServicesPosiStrut Roof Rafter & Purlin SystemIntroductionDefinitionRoof Loading/CamberSet OutSizesHold Down DetailsBracingSpan ChartsSpeedbrace Fixing3333344566777910111315171920212121 212121222326 PosiTrussPosiJoistPosiPlus3 INTRODUCTIONPosiStrut range of products are parallel chord trussesusing

2 Timber chords on flat and the unique PosiStrut metal webs. PosiTruss is a made to order parallel chorded trusscommonly used as long span floor joists. They providean economical and high quality floor structure which iseasily assembled and provides excellent access forplumbing, electrical services and air conditioning may also be used for long span rafters orpurlins to carry tile or steel deck PosiTrusses are designed and manufactured to orderfor specific projects, they can incorporate internal beamsand special support and PosiPlus trusses incorporate specialtrimmable ends and are available ex stock. PosiJoist and PosiPlus are designed specifically for use as floorjoists in domestic type structures and should not be usedfor other applications without advice from a PosiStrut range of products are available in nominal 200, 250, 300, 360 and 400mm depth.

3 Actualoverall Truss depth depends on Timber sizes used for thechords, and is provided in the design tables enclosed. PosiStruts make more efficient use of Timber than conventional joists, as they have Timber concentrated atthe top and bottom of the Truss where it works most efficiently. This concept is similar to that of steel universal beams, where the majority of steel is located inthe flanges. The efficient use of Timber , combined withthe strength of the PosiStrut webs, make the PosiStrut range of products very lightweight, yet strongstructural offer the following advantages over solidjoists: Plumbing, electrical conduit and other services can berun between chords and webs. No drilling or notching required to accommodate services.

4 Additional width available for fixing flooring. Ceiling material can be fixed directly to the trussbottom chords. Larger clear spans. Internal load bearing walls, piers or stumps andbearers can be reduced or eliminated. Shrinkage problems sometimes encountered withunseasoned solid Timber are reduced or eliminated. Lightweight and easy to handle. PosiJoist and PosiPlus trusses may be trimmed tolength on site. Load sharing ability. Strongback bracing increases floor stiffness andreduces squeaky floors. Optional top chord support reduces on-site labour. With Posi-Purlins, roof and ceiling can be fixed direct. Top chord floor SystemDEFINITIONSL oadbearing Partition Walls- walls which carry roofand/or upper floor loads in addition to their own selfweight and wall bearing Partition Walls - walls whichimpart self weight only to supporting Flooring- flooring fitted continuously fromexternal wall to external wall prior to the installation ofinternal partition Flooring- flooring fitted for each room after internal walls have been bracing members running at right anglesto PosiStruts which provide load sharing between adjacent STIFFNESSThe dynamic response of floor systems to foot traffic andother moving loads is dependant on many factors suchas the floor plan of supported walls, applied load, furniturelayout, etc.

5 The comfort and expectations of occupantsalso varies widely and is very have been designed so that the maximumspan recommended in Tables 1 to 8 conforms to thevibration standard set out in , ResidentialTimber-Framed Construction, Part 1 - design selecting a PosiStrut for your applicationconsideration should be given to the springiness of thefloor. Generally the floor stiffness provided by the Tables meets the expectations of most PosiStruts are near their maximum span forlarge open areas like rumpus rooms and family rooms, orwhere additional floor stiffness is required the maximumspans given in Tables 1 to 8 should be LOADINGPosiStruts have been designed for the Loads- are due to the mass of the structure andpermanent fixtures.

6 An allowance has been made inthese designs for the following permanent loads:Flooring- 22mm particle board flooring or equivalent 13mm plasterboard direct or 10 mm plasterboard on covering- normal floor covering loads or vinyl tiles. If, clay or heavy ceramic tilesare to be used, on large areas ( greater than 3 square metres), further professional advice shouldbe sought before commencing Loads- are temporary loads due to furniture orpeople which may vary over time. PosiStrut floor systems in this manual have beendesigned for the following live loads:Domestic floors = / wards and hotel rooms = / for general use = / areas without seating such as concert halls, bars, public lounges = / :1. The PosiStrut span chart in the tables, are notdesigned to support load bearing walls.

7 All roofloads to be supported by external wall only. ForPosiStruts that must support load bearingwalls, contact your nearest MiTek Minimum Joint Group Loads- the PosiStrut sizes, bracing andconnection details are suitable for design category H1and H2 domestic structures in accordance CHARTS FOR TOP CHORDSUPPORT floor TRUSSESNote:Spans have been produced for 45mm wide top chord Spans for 35mm thick Timber *Important Note:For spans in the range of 1100 to 2600, top chords should be a minimum grade of F11 or MGP12 to conform to #Important Note:For spans in the range of 1100 to 2600, top chords should be a minimum grade of F8 or MGP12 to conform to SizeTimberSize(mm x mm)OverallDepth(mm)PSW3520 PSW3525 PSW353035 x 7035 x 9035 x 7035 x 9035 x 7035 x 90197197248248302302------39004100410049 0041005200450047005100550057006100F5F8F1 7-4000-4600*-5200*MGP1041004500500053005 6006000 MGP12450047005200560057006200 MGP15-----11003000#37003100#39003100#390 0390040004800500053005700F5F8F17---3900* -4100*MGP10370040004500490049005400 MGP12390040004700520053005800 MGP15 Timber Grade450mm PosiStrut Centres600mm PosiStrut CentresTable Spans for Domestic floor Loads - Live Load kPaMaximum Spans for 45mm thick Timber *Important Note.

8 For spans in the range of 1100 to 2600, top chords should be a minimum grade of F8 or MGP12 to conform to SizeTimberSize(mm x mm)OverallDepth(mm)PSW4525 PSW4530 PSW4536 PSW454045 x 7045 x 9045 x 7045 x 9045 x 7045 x 9045 x 7045 x 9024824830230236036041241244004800490054 002600*58003400*620048005200540058005800 6300640068005400570060006400660071007100 7600F5F8F1745005100510058005600640060006 900 MGP1053005600590063006500690069007400 MGP1255005800610065006800720073007700 MGP153500*43004100*4700-4700-47004400480 0500053005500580058006300500053005600570 06000640066007000F5F8F173900430044004900 4200560047005800 MGP1048005200540058005900620064006800 MGP1251005300570057006200640067007000 MGP15 Timber Grade450mm PosiStrut Centres600mm PosiStrut CentresTable Spans for Domestic floor Loads - Live Load kPaRESIDENTIAL LOADSSPAN CHARTS FOR BOTTOM CHORDSUPPORT floor TRUSSESM aximum Spans for 35mm thick Timber *Important Note.

9 For spans in the range of 1100 to 2600, top chords should be a minimum grade of F8 or MGP12 to conform to Spans for 45mm thick timberPosiStrut SizeTimberSize(mm x mm)OverallDepth(mm)PSW4525 PSW4530 PSW4536 PSW4540 PosiJoist SizePJ25-70PJ25-90PJ30-70PJ30-90--PJ40-7 0PJ40-9045 x 7045 x 9045 x 7045 x 9045 x 7045 x 9045 x 7045 x 9024824830230236036041241244004900490055 0055006000590065004900520055005800600064 0065006900540058006100650067007100720077 00F5F8F174500510051005700560064006100690 0 MGP1053005600600063006500700071007500 MGP1255005900620066006900720074007900 MGP1538004300430048004700540051005600440 0480051005400560060006100640050005400570 060006200660067007100F5F8F17390045004500 50004900560054006000 MGP1049005200550059006100650066007000 MGP1251005500580061006300670069007300 MGP15 Timber Grade450mm PosiStrut Centres600mm PosiStrut CentresTable Spans for Domestic floor Loads - Live Load kPaPosiStrut SizeTimberSize(mm x mm)OverallDepth(mm)

10 PSW3520 PSW3525 PSW353035 x 7035 x 9035 x 7035 x 9035 x 7035 x 9019719724824830230211003800110045001100 5000380042004600500053005600440048005200 550058006200F5F8F173400*40004100*4600450 0*5200 MGP10430046005100540057006100 MGP12460049005300570059006300 MGP15-3300110039001100440034003800420046 0048005200400043004800510054005800F5F8F1 73100*34003400*40004000*4500 MGP10380042004500480049005600 MGP12400043004900520055005900 MGP15 Timber Grade450mm PosiStrut Centres600mm PosiStrut CentresTable Spans for Domestic floor Loads - Live Load kPa5*Important Note:For spans in the range of 600 to 2600, top chords should be a minimum grade of F8 or MGP12 to conform to *Important Note:For spans in the range of 600 to 2600, top chords should be a minimum grade of F8 or MGP12 to conform to SizeTimberSize(mm x mm)OverallDepth(mm)