Conventional Roof Framing Residential Studies Certificate IV   Class Exercise 2 - 180 Residential Studies Certificate IV 2182D

Using the Floor Plan & Details provided complete the Preliminary Calculations so that the most economical Size, Span and Spacing Of the Ceiling and Roof members can be achieved.

Floor Plan Class Exercise 2 Note: Hyspan LVL Strutting Beams to Dining / Lounge & Bedroom 1 as shown

Preliminary Calculations Common Rafter True Length of Common Rafter Pitch 180 Half Span = 8.150 – 0.300 2 = 3.925m Rise = Tan 180 x 3.925 = 1.275m TLCR = 4.127 Rise 1.275 TLCR = 3.925 Cos 180 = 4.127m 180 Half Span 3.925

Calculate Common Rafter Span & RLW of Underpurlin 2.064 4.127 2.064 RLW = 4.127 2 = 2.064m Span of Rafter = 2.064m Say 2.100m RLW of Underpurlin = 2.064m Say 2.100m

Calculate Eaves Overhang – Eaves RLW 0.788m TL O/Hang = 0.600 + 0.150 COS 180 = 0.788m RLW Eaves = 0.788m 0.150 0.600

Calculate Fan Strut Lengths & Distance X. 2.064 2.064 Strut = Tan180 x 2.064 = 0.671 2.064 Strut 0.788 0.671 Dist. X = 1.862 run of rafter = 3.925 100mm width Distance X = Run of rafter divided by 2 less 100mm plate width: 3.925/2 = 1.962 – 100 = 1862

Calculate Fan Strut Length 0.671 0.671 Fan Strut =  0.6712 + 0.6712 = 0.949m or = 0.671 cos 450 0.671 0.949 0.949 Half Spread Fan Strut = 0.671m Fan Strut Length = 0.949m

Summary: Rafter Span = 2.064 Say 2.100 RLW Underpurlin = 2.064 Say 2.100 Overhang eaves = 0.788 Purlin horizontal Set Out, “Distance X” = 1.862 Half Spread Fan Strut = .671 Full spread Fan Strut = 1.342 Fan Strut Length = 0.949

Using the information from the Preliminary Calculations & The Job Specification Fill in the Project job sheets to arrive at final design requirements.

Member Rule/Table Size Comments General Information from Project Details Member Rule/Table Size Comments Timber Species Timber Grade Supp. No. Roof Mass Type/Construct. Floor to Ceiling height Eaves Width Seasoned S/Wood MGP 15 6 – N3 60Kg/m2 Conventional 2.700 0.600 Fill in comments column with information from project specification

Member Rule/Table Size Comments 90 x 35 @ Using A.S. 1684.2 (2006) – Section 7 Roof Framing 1. Obtain information for Ceiling Joists to complete job sheet. Member Rule/Table Size Comments Ceiling Joists R T 90 x 35 @ 600mmc/c Single Span Continuous Span (over more than 1 span) 7.2.4 2.400 21 2.800 7.3.6 Page 81 – rule 7.2.4 ceiling joists (building practice) 2. Page 98 – rule 7.3.6 ceiling joists (member sizes) 3. Determine Span Table of supplements (supp. 6, N3, s/softwood, MGP 15) 4. Find allowable spans for 90 x 35 MGP15 ceiling joists from table 21 supp. 6

Hanging Beams 2. Obtain information for Hanging Beams 7.2.5 23 7.3.7 R Member Rule/Table Size Comments Room Span CLW Hanging Beams R T Bedroom 1 Bedroom 2 Bedroom 3 Bath / WC Laundry Kitchen Family Dining Lounge Garage W/shop 7.2.5 2 / 90 x 45 2.475 1.720 23 120 x 45 2.930 2.050 120 x 35 2.730 2.050 7.3.7 90 x 45 2.540 1.225 90 x 35 1.680 1.725 140 x 45 3.770 1.720 2 / 170 x 35 3.770 2.055 170 x 35 3.830 2.055 170 x 35 3.830 2.055 140 x 45 3.300 2.775 N / A Page 82 – rule 7.2.5 Hanging Beams (building practice) 2. Page 99 – rule 7.3.7 Hanging Beams (member sizes) 3. Determine Span Table of supplements (supp. 6, N3, s/softwood, MGP 15) 4. Determine Hanging Beams to rooms from table 23 supp. 6, MGP15

Member Rule/Table Size Comments 3. Obtain information for Rafters Member Rule/Table Size Comments Common Rafter R T Rafter Spacing Span Eaves O/Hang Underpurlin is mid-span of Rafter 7.2.11 120 x 35 0.600 29 2.100 7.3.13 0.788 Fill in comments column with information from project specification & Prelim. Calcs. Page 86 – rule 7.2.11 Rafters (building practice) 2. Page 105 – rule 7.3.13 Rafters (member sizes) 3. Determine Span Table of supplements (supp. 6, N3, s/softwood, MGP 15) Determine Rafter Size from table 29 supp. 6, MGP15, N3 (Check - single or continuous span - roof mass – span – O/hang)

Member Rule/Table Size Comments 4. Obtain information for Collar Ties Member Rule/Table Size Comments Collar Ties R T or Length 7.2.16 & 7.3.17 70 x 35 3.805 7.6 (page 110) Check section 7 (Roof Framing) for information – rules & tables for Collar Ties Note: Find rules relating to Collar Ties. Page 90 Rule 7.2.16 & Page 109, Rule 7.3.17 – Other members or Components, states that Table 7.6 give details for miscellaneous roof framing members not given in span tables of the supplements. Page 110, Table 7.6 – Collar Ties gives required Information Refer to floor plan to calculate length of collar tie: 7.610 / 2 = 3.805 From Table 7.6 – Ties to 4200mm long for F8/MGP12 or higher stress grade – 70 x 35

Member Rule/Table Size Comments 5. Obtain information for Ridge board Member Rule/Table Size Comments Ridge R T Not Strutted 7.2.12 7.6 (page 110) Check section 7 (Roof Framing) for information – rules & tables for Ridge boards Note: Find rules relating to Ridge boards Page 86, Rule 7.2.12 – The size of Ridge boards shall be determined from Table 7.6 Table 7.6 Ridge boards – Refers to Unstrutted ridges in coupled roofs has having a depth not less than length of Rafter Plumb-Cut x 19mm thick

Ridge 0.126 Rafter 120 x 35 MGP 15 Seasoned Softwood Refer Table 7.6 (AS 1684.2) page 110, Ridge depth = rafter plumb cut x 19mm thick. Therefore use 140 x 19 MGP 15 S/wood. 0.126 Rafter 120 x 35 MGP 15 Seasoned Softwood Length of Plumb Cut Length of Plumb cut = Rafter Depth Cos. Roof Pitch = 0.120 Cos. 180 = 0.126 0.120

Member Rule/Table Size Comments 5. Obtain information for Ridge board Member Rule/Table Size Comments Ridge R T Not Strutted 7.2.12 140 x 19 7.6 (page 110) Check section 7 (Roof Framing) for information – rules & tables for Ridge boards Note: Find rules relating to Ridge boards Page 86, Rule 7.2.12 – The size of Ridge boards shall be determined from Table 7.6 Table 7.6 Ridge boards – Refers to Unstrutted ridges in coupled roofs has having a depth not less than length of Rafter Plumb-Cut x 19mm thick Calculate Rafter Plumb-Cut Length - 0.120 = 0.126 (Therefore 140 x 19 Ridge) cos 180

Member Rule/Table Size Comments 6. Obtain information for Hip Rafter (Hip) Member Rule/Table Size Comments Hip Rafter R T Note: Plan shows Roof is a Gable Roof – Therefore NO HIPS REQUIRED

Member Rule/Table Size Comments 7. Obtain information for Under purlins Member Rule/Table Size Comments Underpurlin R T 140 x 70 Span Direct from Span Tables of Supplements. Max. Span Interpolated = 7.2.10 7.3.12 3.633m 28 Check section 7 (Roof Framing) for information – rules & tables for Underpurlins Note: Find rules relating to Underpurlins Page 84, Rule 7.2.10 – Underpurlins Page 104, Rule 7.3.12 - Size of Underpurlins Span Table 28 of Supplements Refer Table 28 – Continuous Span - for allowable span to Underpurlin (Rafter spacing = 0.600, RLW = 2100 & Roof Mass = 60Kg/m2) Interpolate allowable Max. Span for Underpurlin size 140 x 70 from Table 28

Member Rule/Table Size Comments 8. Obtain information for Struts (Roof Strutting) Member Rule/Table Size Comments Struts R T or Straight Strut Length = Fan Strut Length = 7.2.15 90 x 45 70 x 70 0.671m 7.2.15.3 0.949m 7.6 Check section 7 (Roof Framing) for information – rules & tables for Struts Note: Find rules relating to Struts Page 87, Rule 7.2.15 – Roof Strutting & Page 90, Rule 7.2.15.3 Fan Struts. Page 109, Rule 7.3.17 - The size of Miscellaneous roof members shall be determined from Table 7.6 From Prelim. Calcs. Fill in lengths for straight & fan struts. Using Table 7.6 Determine section size of Struts – (Tile Roof)

Member Rule/Table Size Comments 9. Obtain information for Strutting Beams Member Rule/Table Size Comments Strutting Beams Supporting roof & Ceiling Loads. Use: Hyspan LVL Location Span Spacing Lounge/Dining Bedroom 1 Use Hyspan LVL Span Tables for Residential Building Calculate spans for strutting beams from floor plan

Beam to Lounge / Dining, Span = 4.110 Beam to Bedroom 1, Span = 3.440

Member Rule/Table Size Comments 8. Obtain information for Strutting Beams Member Rule/Table Size Comments Strutting Beams Supporting roof & Ceiling Loads. Use: Hyspan LVL Location Span Spacing Lounge/Dining Bedroom 1 4.110 Centre 3.440 Use Hyspan LVL Span Tables for Residential Building Calculate spans for strutting beams from floor plan Fill in span information Spacing is centre of rooms Determine table number from Hyspan LVL tables to select beam section sizes

Use table 18 for Beam To Lounge/Dining - Span = 4.110 & Beam to Bedroom 1 - Span = 3.440 Supporting Underpurlins & Hanging Beams Go to Table 18 for member size

RLW = 2.475 B1 = 3.830 L/D Lounge/ Dining Beam Span = 4.110 TILE ROOF AND CEILING Maximum Span (M) RLW = 2.475 B1 = 3.830 L/D Lounge/ Dining Beam Span = 4.110 Lounge/ Dining Beam = 300x75 Bedroom 1 Beam Span = 3.440 Bedroom 1 Beam = 2/200 x 45

Member Rule/Table Size Comments 8. Obtain information for Strutting Beams Member Rule/Table Size Comments Strutting Beams Supporting roof & Ceiling Loads. Use: Hyspan LVL Location Span Spacing Lounge/Dining Bedroom1 300 x 75 4.110 Centre T 18 2/ 200 x 45 3.440 Use Hyspan LVL Span Tables for Residential Building Calculate spans for strutting beams from floor plan Fill in span information Spacing is centre of rooms Determine table numbers from Hyspan LVL tables to select beam section sizes Fill in Data for Lounge/Dining Beam Fill in Data for Bedroom 1 Beam

Part A can now be completed. On the plan supplied clearly mark all Hanging Beams, Underpurlins and any Strutting Beams & / or Special Strutting Beams supporting Roof and Ceiling loads.

Single struts Strutting Beams Under Purlins Fan struts Hanging Beams

Class Exercise 2 – Now Complete