GUIDELINES FOR THE DESIGN FIXING & BRACING …

1 HOME OF GANG-NAILBUILDING SYSTEMSTo find out more about MiTek s products & systems, call your local state office or visit our web site: (03) 8795 8888 NSW (02) 8525 8000 QLD (07) 3268 1666 SA (08) 8234 1326 WA(08) 9411 2845 NZ(09) 274 7109 MALAYSIA(603) 3176 7473 GUIDELINES FOR THE DESIGNFIXING & BRACING OF Posi-STRUTFLOOR & ROOFTRUSS SYSTEMSGUIDELINES FOR THE DESIGNFIXING & BRACING OF Posi-STRUTFLOOR & ROOFTRUSS SYSTEMSJANUARY 20072 TABLE OF CONTENTSPosi-STRUT Floor Truss SystemIntroductionAdvantagesDefinitionsF loor StiffnessFloor LoadingSpan Charts for Bottom Chord SupportSpan Charts for Top Chord SupportSupporting StructureHandling and StorageSet Out and PlacementTrimming On SiteSupporting External WallsSupported Non-Load Bearing WallsSupport DetailsFixing and ConnectionsStrongbacksStair OpeningsCantileversBracingMechanical ServicesPosi-STRUT Roof Rafter & Purlin SystemIntroductionDefinitionRoof Loading/CamberSet

2 OutSizesHold Down DetailsBracingSpan ChartsSpeedbrace Fixing3333344556668910121416181920202020 2020212225 Posi-TRUSSPosi-JOISTPosi-PLUS3 INTRODUCTIONPosi-STRUT range of products are parallel chordtrusses using timber chords on flat and the uniquePosi-STRUT metal webs. Posi-TRUSS 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 Posi-TRUSSES are designed and manufactured toorder for specific projects, they can incorporate internalbeams and special support and Posi-PLUS trusses incorporate special trimmable ends and are available ex stock.

3 Posi-JOIST and Posi-PLUS are designed specificallyfor use as floor joists in domestic type structures andshould not be used for other applications without advicefrom a qualified Posi-STRUT range of products are available innominal 200, 250, 300 and 400mm depth. Actual overalltruss depth depends on timber sizes used for the chords,and is provided in the DESIGN tables enclosed. Posi-STRUTS make more efficient use of timber thanconventional 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 univer-sal beams, where the majority of steel is located in theflanges.

4 The efficient use of timber, combined with thestrength of the Posi-STRUT webs, make the Posi-STRUT range of products very lightweight, yetstrong structural 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. 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.

5 Lightweight and easy to handle. Posi-JOIST and Posi-PLUS trusses may betrimmed to length 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 Posi-STRUTS which provide load sharing betweenadjacent Limit State STIFFNESSThe dynamic response of floor systems to foot traffic andother moving

6 Loads is dependant on many factors suchas the floor plan of supported walls, applied load, furniturelayout, etc. The comfort and expectations of occupantsalso varies widely and is very have been designed so that the maximum span recommended in Tables 1 to 4 conformsto the vibration standard set out in ,Residential Timber-Framed Construction, Part 1 - selecting a Posi-STRUT for your applicationconsideration should be given to the springiness of thefloor. Generally the floor stiffness provided by the Tables meets the expectations of most Posi-STRUTS 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 6 should be LOADINGPosi-STRUTS have been designed for the followingDeadand Live Loads- are due to the mass of the structure andpermanent fixtures.

7 An allowance has been made inthese designs for the following permanent loads:Flooring- 22 mm Particle board flooring or equivalent 13 mm 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. Posi-STRUT floor systems in this manual have beendesigned for kPa which is suitable for domestic commercial or public buildings seek advicefrom your Posi-STRUT :The Posi-STRUT span chart tables attached, arenot designed to support load bearing walls.

8 All roof loadsto be supported by external wall only. For Posi-STRUTS that must support load bearing walls, contact your nearest MiTek CHARTS FOR TOP CHORDSUPPORT FLOOR TRUSSESNote:1. All charts designed using LSD Minimum Joint Group Spans have been produced for 45mm wide top chord Spans for 35 mm thick timber*Important Note:For spans in the range of 1100 to 2600, top chords may require to be a minimum grade of F11 or MGP12 to conform to #Important Note:For spans in the range of 1100 to 2600, top chords may require to 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 90197197248248302302-1000-3200#-3300#380 0400040004900400051003800430047005000500 05600440046005100540057006000F5F8F11F17- 4000-4600#-5200#MGP104200460049005300550 05900 MGP12450048005200550058006100 MGP15-----11003000*36003000*39003000*390 0360039003700460037004800390039004700490 052005600F5F8F11F17---3500#-3900#MGP1038 0039004500480051005400 MGP12390039004800510053005700 MGP15 Timber Grade450 mm Posi-STRUT Centres600 mm Posi-STRUT CentresTable Spans for Domestic Floor Loads - Live Load kPaMaximum Spans for 45 mm thick timber*Important Note.

9 For spans in the range of 1100 to 2600, top chords may require to be a minimum grade of F8 or MGP12 to conform to SizeTimberSize(mm x mm)OverallDepth(mm)PSW4525 PSW4530 PSW454045 x 7045 x 9045 x 7045 x 9045 x 7045 x 9024824830230241241243004700490053004800 *630047005100530057006300670049005300550 0590065007000530056005900630060007500F5F 8F11F17450051005100580061006900 MGP10520055005800620069007300 MGP12540057006100650072007700 MGP153700*42004200*4700-5500430047004900 5200570061004500480050005400590064004900 52005500560065006900F5F8F11F173900450045 00500054005900 MGP10480050005300570063006700 MGP12500052005600560066006900 MGP15 Timber Grade450 mm Posi-STRUT Centres600 mm Posi-STRUT CentresTable Spans for Domestic Floor Loads - Live Load kPaSPAN CHARTS FOR BOTTOM CHORDSUPPORT FLOOR TRUSSESNote:1.

10 All charts designed using LSD Minimum Joint Group Spans for 35 mm thick timber*Important Note:For spans in the range of 1100 to 2600, top chords may require to be a minimum grade of F8 or MGP12 to conform to Spans for 45 mm thick timberPosi-STRUT SizeTimberSize(mm x mm)OverallDepth(mm)PSW4525 PSW4530 PSW4540 Posi-JOIST SizePJ25-70PJ25-90PJ30-70PJ30-90PJ40-70P J40-9045 x 7045 x 9045 x 7045 x 9045 x 7045 x 9024824830230241241244004900490055005900 6500490052005500580065006900510054005700 600067007200540058006100650072007700F5F8 F11F17460052005200580062007100 MGP10530056006000630071007500 MGP12550059006200660074007900 MGP1538004300430048005200560044004800510 0540061006400460050005300560063006700500 054005700600067007200F5F8F11F17400045004 500510055006100 MGP10490052005500590066007000 MGP12510055005800610068007300 MGP15 Timber Grade450 mm Posi-STRUT Centres600 mm Posi-STRUT CentresTable Spans for Domestic Floor Loads - Live Load kPaPosi-STRUT