6 Ceiling Joists Horizontal Members with ends rested on top wall plate Generally spaced at 450mm or 600mmInitially ceiling material will determine spacingSizes and Grading are determined from Span Tables Ceiling Lining may be nailed directly to Joists
7 Ceiling Joists Provide Lateral Tie between opposing Rafters Portal Frame DesignWalls Require Alternate BracingButressingTypical Residential Design(Coupled Roof)
13 Ceiling are an Important Structure Support For Ceiling LiningsTie bases of Rafters (Stop Spreading)Straighten Walls (Between Intersecting Walls)Diaphragm Bracing (9000mm Max)
14 Joining Ceiling Joists Be only made at points of supportLapped over support 3 times depth - 6 hand driven nails 75mm x machine driven nails 75mm x or 1 M12 BoltButt joined - fish plates to each side - minimum length x depth of joist - 19mm x Depth of Ceiling JoistNailing plates as per manufacturers detail
16 Selecting Members 10mm Plasterboard Direct Fix Single Span Ceiling Joist Ax = 2000mm450 c to cWhat size Ceiling Joist is Required ?
17 Remember First Check the NOTES! From Appendix B Refer p99 AS1684.2Remember First Check the NOTES!From Appendix B10mm Plaster Board = 7.5kg/sqmTherefore OKCheck Grade !What are Ceiling Masses ?Refer Appendix B – AS450 CentresNext Highest Span above Required 2000mm Span
18 Selecting Members Single Span Ceiling Joist A x = 2000mm 450 c to c120mm x 35mmSingle SpanCeiling Joist Bx = 2700mm450 c to c.What Size CeilingJoists are required?
19 Next Largest span after 2700mm Check for Required Grade !450 c to c
20 Selecting Members Continuous Spans 10mm Plasterboard Direct Fix Single SpanCeiling Joist Bx = 2500mm450 c to c120mm x 45mmCeiling Joist A & B – AS 1684 requires joists to be Continuousx + y = 4500mm450 c to cNote – Maximum Span is 2700mm, 4700mm is irrelevant
21 Next Largest span after 2700mm 450 c to c Continuous SpanCheck For Required Grade !
22 Compare Single to Continuous 120 x 45 F7120 x 35 F510mm Plasterboard Direct FixCeiling Joist A & B as Continuous Joist450 c to c,10mm Plasterboard120 x 35 F5 is Sufficient
23 Exercise Complete Question 5 on Workbook 120 x 35 140 x 35 3500 Using MGP 10 select suitable Ceiling JointsJoist X =Joist Y =Using MGP 10 select suitable Ceiling Joints for continuous spanMax Span RequiredCeiling Joist size =120 x 35140 x 353500120 x 35
26 Framing Openings in Ceilings AS clOpenings up to 1000mm – same size as ceiling1000mm up to 3000mm – width increased (accumulatively) by 20% for every 300mm of opening or part there of.
27 Ceiling Openings Example Ceiling Joists 90 x 45 MGP 10 Radiata Pine1800 Square Opening1800 – = 800 (1000mm being maximum allowable to use same members)800mm divided by 300mm = therefore 3 increments45mm x 1.2 = 54mm 1st Increase by 20%54mm x 1.2 = 65mm 2nd Increase by 20%65mm x 1.2 = 78mm 3rd Increase by 20%Therefore minimum size is 90mm x 78mm
28 ExcerciseComplete Questions 4 & 5 in the Worksheet
31 What items determine the sizing of Ceiling Joists? Refer to Span TablesComplete Questions 7 & 7.1 of Workbook
32 Hanging Beams- also referred to as Hangers Hanging Beams provide support to Ceiling Joists where walls are available
33 Connecting Hanging Beams to Ceiling Joists Ceiling Dog
34 Connecting Hanging Beams to Ceiling Joists Unitie4 Timber Connector Nails in Each Member
35 Connecting Hanging Beams to Ceiling Joists Triple Grips35mm x 3.15 Connector Nails in to each member
36 End Support of Hanging Beams Hanging Beams shall be nailed or bolted to a rafterBeam Shall Bear Full Width of Plate on PackingWhere more than 2/3 of the Beam needs to be trimmed a ceiling trimmer is required
37 Isometric ViewComplete Exercise 8 of the Work Book
38 Restraining Deep Hanging Beams What is a Deep Beam ?Where depth is Greater than 7 times the Width
39 Hanging Beams Gable Ends Packing Full Width of Plate. Build up to top of Ceiling JoistsWhere Beam is longer than 3000mm stud required directly belowWhere this occurs at Gable Ends , no ceiling joists to brace end wallThe Beam will also act as a “Binder”
40 Binders refer AS clAt Gable Ends walls do not have Ceiling Joists to Brace them
47 Counter Beams called Hanging Beams in the TAFE GUIDE Reduce Span of Hanging BeamAt 90º to Hanging BeamsSupported on WallsWith stud directly below if longer than 3000mmTrimmed for Roof FinishesSimilar to Hanging Beams
48 Intersection of Hanging & Counter Note – Counter Beam is Supporting Hanging Beam
56 Combined Strutting/Hanging Beams Reduce Span of Ceiling Joists and PurlinSupported on WallsWith stud directly below if longer than 3000mmRoof Load Strutted down to Hanging Beam
57 Check GradeFirst we need to determine what ceiling load it carrying?Roof MassesCheck Notes
58 Ceiling Load Width (CLW) Sheet RoofCeiling Joist Span (x) = 4200Hanging Beam Span = 6000Rafter Span (B) = 4500Therefore CLW = 2100Remember what we are tryingWork out is what load is themember carrying
59 Next we need to calculate what roof load it is carrying?
60 Roof Area Support Sheet Roof Why A ? Strut Down to Beam from Purlin(Roof)Struts down to top plate distance between these 2 struts is ATherefore strut takes load ½ way between other supports5000/2 = AA = 2500Ceiling Joist Span (x) = 4200Hanging Beam Span (A) = 5000Rafter Span (B) = 4500
61 Roof Area Support Why B? Rafter is supported by Purlin Rafter Load is Transferred thruPurlin StrutRidge Strut,Top PlateTherefore Beam takes load ½ way between supports (4500/2)= 2250Ceiling Joist Span (x) = 4200Hanging Beam Span (A) = 5000Rafter Span (B) = 4500
62 Remember Ceiling Load Width = 2100 Next we need to calculate what roof load it is carrying?2.250 (Rafter Span) x2.500 ( HB Span)=5.625Required Hanging Beam Span = 5000Required Hanging Beam Span = 5000mm
63 Combined Strutting/Counter Beams Reduce Span of Hanging BeamSupported on WallsWith stud directly below if longer than 3000mmRoof Load Strutted down to Hanging Beam
85 Ceiling Trimmers 6650 ÷ 600 = 11.083 = 12 + 1 to Close = 13 + 1 for intersection =14
86 Ceiling Trimmers 6650 ÷ 600 = 11.083 = 12 + 1 to Close = 13 + 1 for intersection =143350 ÷ 600 = 5.6 = 6+ 1 to Close = 7
87 Ceiling Trimmers 6650 ÷ 600 = 11.083 = 12 + 1 to Close = 13 + 1 for intersection =14800 ÷ 600 = 1.3 = 2+ 1 to Close = 33350 ÷ 600 = 5.6 = 6+ 1 to Close = 7
88 Ceiling Trimmers 6650 ÷ 600 = 11.083 = 12 + 1 to Close = 13 + 1 for intersection =14800 ÷ 600 = 1.3 = 2+ 1 to Close = 3Answer=Note as blocks no need to specify length3350 ÷ 600 = 5.6 = 6+ 1 to Close = 7