Conventional Roof Framing Class Exercise 2 — 180

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

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. 925 m Rise = Tan 180 x 3. 925 = 1. 275 m Rise 1. 275 TLCR = 4. 127 180 Half Span 3. 925 TLCR = 3. 925 Cos 180 = 4. 127 m

Calculate Common Rafter Span & RLW of Underpurlin 2. 06 4 4. 12 7 RLW = 4. 127 2 = 2. 064 m Span of Rafter = 2. 064 m Say 2. 100 m RLW of Underpurlin = 2. 064 m Say 2. 100 m 2. 06 4

Calculate Eaves Overhang – Eaves RLW 0. 7 88 m TL O/Hang = 0. 600 + 0. 150 COS 180 = 0. 788 m RLW Eaves = 0. 788 m 0. 150 0. 600

Calculate Fan Strut Lengths & Distance X. Strut = ? 2. 064 2. 06 4 Strut = Tan 180 x 2. 064 = 0. 671 2. 06 4 Strut 0. 78 8 0. 671 Dist. X = 1. 862 run of rafter = 3. 925 Distance X = Run of rafter divided by 2 less 100 mm plate width: 3. 925/2 = 1. 962 – 100 = 1862 100 mm width

Calculate Fan Strut Length 0. 671 Fan Strut = 0. 6712 + 0. 6712 = 0. 949 m or 0. 671 0. 949 = 0. 671 cos 450 = 0. 949 m Half Spread Fan Strut = 0. 671 m Fan Strut Length = 0. 949 m 0. 949

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.

General Information from Project Details Member Rule/Table Size Comments Timber Species Seasoned S/Wood Timber Grade MGP 15 Supp. No. 6 – N 3 Roof Mass 60 Kg/m 2 Type/Construct. Conventional Floor to Ceiling height Eaves Width 2. 700 0. 600 Fill in comments column with information from project specification

Using A. S. 1684. 2 (2006) – Section 7 Roof Framing 1. Obtain information for Ceiling Joists to complete job sheet. Member Size R 7. 2. 4 T 21 90 x 35 @ R Ceiling Joists Rule/Table 7. 3. 6 600 mmc/c Comments Single Span 2. 400 Continuous Span (over more than 1 span) 2. 800 1. 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, N 3, s/softwood, MGP 15) 4. Find allowable spans for 90 x 35 MGP 15 ceiling joists from table 21 supp. 6

2. Obtain information for Hanging Beams Member Hanging Beams Rule/Table R Size 7. 2. 5 2 T 23 R 7. 3. 7 / 90 x 45 120 x 35 90 x 45 90 x 35 140 x 45 2 / 170 x 35 140 x 45 1. 2. 3. 4. Comments Room Span CLW Bedroom 1 Bedroom 2 Bedroom 3 Bath / WC Laundry Kitchen Family Dining Lounge Garage W/shop 2. 475 2. 930 2. 730 2. 540 1. 720 2. 050 1. 225 1. 680 1. 725 3. 770 3. 830 3. 300 1. 720 2. 055 2. 775 N/A Page 82 – rule 7. 2. 5 Hanging Beams (building practice) Page 99 – rule 7. 3. 7 Hanging Beams (member sizes) Determine Span Table of supplements (supp. 6, N 3, s/softwood, MGP 15) Determine Hanging Beams to rooms from table 23 supp. 6, MGP 15

3. Obtain information for Rafters Member Rule/Table R 7. 2. 11 T 29 R Common Rafter 7. 3. 13 Size 120 x 35 Comments Rafter Spacing 0. 600 Span 2. 100 Eaves O/Hang 0. 788 Underpurlin is mid-span of Rafter Fill in comments column with information from project specification & Prelim. Calcs. 1. Page 86 – rule 7. 2. 11 Rafters (building practice) 2. 3. 4. Page 105 – rule 7. 3. 13 Rafters (member sizes) Determine Span Table of supplements (supp. 6, N 3, s/softwood, MGP 15) Determine Rafter Size from table 29 supp. 6, MGP 15, N 3 (Check - single or continuous span - roof mass – span – O/hang)

4. Obtain information for Collar Ties Member Collar Ties Rule/Table R 7. 2. 16 & 7. 3. 17 Size 70 x 35 or Comments Length 3. 805 T 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 4200 mm long for F 8/MGP 12 or higher stress grade – 70 x 35

5. Obtain information for Ridge board Member Ridge Rule/Table R 7. 2. 12 Size Comments Not Strutted T 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 Ridge boards – Refers to Unstrutted ridges in coupled roofs having a depth not less than length of Rafter Plumb-Cut x 19 mm thick

Refer Table 7. 6 (AS 1684. 2) page 110, Ridge depth = rafter plumb cut x 19 mm thick. Therefore use 140 x 19 MGP 15 S/wood. 0. 126 Ridge Rafter 120 x 35 MGP 15 Seasoned Softwood Length of Plumb Cut Length of Plumb cut = Rafter Depth Cos. Roof Pitch 0. 120 = 0. 120 Cos. 180 = 0. 126

5. Obtain information for Ridge board Member Ridge Rule/Table R Size 7. 2. 12 Comments Not Strutted 140 x 19 T 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 Ridge boards – Refers to Unstrutted ridges in coupled roofs having a depth not less than length of Rafter Plumb-Cut x 19 mm thick Calculate Rafter Plumb-Cut Length - 0. 120 = 0. 126 cos 180 (Therefore 140 x 19 Ridge)

6. Obtain information for Hip Rafter (Hip) Member Hip Rafter Rule/Table Size Comments S R NO e r fo e er R T f o Ro e s fi N : te o lan P ws ho s oo R a l ab G Th – P HI ED R RE UI Q

7. Obtain information for Under purlins Member Rule/Table R 7. 2. 10 R 7. 3. 12 T Underpurlin Size Comments 140 x 70 Span Direct from Span Tables of Supplements. 28 3. 633 m Max. Span Interpolated = 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 = 60 Kg/m 2) Interpolate allowable Max. Span for Underpurlin size 140 x 70 from Table 28

8. Obtain information for Struts (Roof Strutting) Member Size R 7. 2. 15 90 x 45 R Struts Rule/Table 7. 2. 15. 3 T 7. 6 Comments Straight Strut Length = 0. 671 m Fan Strut Length = 0. 949 m or 70 x 70 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)

9. Obtain information for Strutting Beams Member Rule/Table Size Comments Strutting Beams • Use: Hyspan LVL Location Spacing • Supporting roof & Ceiling Loads. 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

8. Obtain information for Strutting Beams Member Rule/Table Size Comments Strutting Beams • Use: Hyspan LVL Location Spacing • Supporting roof & Ceiling Loads. Lounge/Dining 4. 110 Centre Bedroom 1 3. 440 Centre • 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 B 1 = 3. 830 L/D TILE ROOF AND CEILING Maximum Span (M) Lounge/ Dining Beam Span = 4. 110 Lounge/ Dining Beam = 300 x 75 Bedroom 1 Beam Span = 3. 440 Bedroom 1 Beam = 2/200 x 45

8. Obtain information for Strutting Beams Member Rule/Table Size Location Span Spacing Strutting Beams • Use: Hyspan LVL • Supporting roof & Ceiling Loads. T 18 Comments 300 x 75 2/ 200 x 45 4. 110 Lounge/Dining Centre 3. 440 Centre Bedroom 1 • 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 Fan struts Hanging Beams Under Purlins

Class Exercise 2 – Now Complete