Span Table
How to use our span table:
HOW IT WORKS: The different elements are colour coded in the cross-section diagram and are to be read from the span table in the same colour. All rafters are shown as blue and the table in blue must be read to find the timber size. Make sure that the headings are correct, (sheeting or tiles / with or without a ceiling) then follow the column down to the required span and then read the RAFTER SIZE REQUIRED on the left.
EXAMPLE: A rafter span of 4,80 meters for roof sheeting without a ceiling will require a 38X228 S5 Rafter. (ringed in red.) On the right side in the yellow table is the beam design which requires the incoming rafter span that is to be supported by the beam (indicated in the section diagram) and the length of the beam. Read down the column to the span of the incoming rafter and then across until you reach the span of the supporting beam.
Guideline Span Table for SA Pine Rafters - Sheeting & Tiles
- WIND CATEGORIES: B, C and D
- Tables valid for Simply Supported Beams only
- No additional loads such as solar panels or water tanks have been allowed.
- Min. rafter pitch for tiles 17.5 deg. using a 38×38 tile batten @ 320mm centres.
- Min. rafter pitch for sheeting 10.0 deg. using a 50×76 sheeting purlin @ 1,200mm centres.
Roofing Span Table in m for SA Pine Rafters
| RAFTERS SIZE REQUIRED | RAFTERS TABLE | ||||
| with ceiling | without ceiling | ||||
| SECTION | GRADE | SHEETING 1200mm | TILES 760mm | SHEETING 1200mm | TILES 760mm |
| 38X114 | S5 | 2 | 2.1 | ||
| 2.4 | 2.5 | ||||
| 38X152 | S5 | 2.75 | 3 | ||
| 3.1 | 3.3 | ||||
| 38X228 | S5 | 4 | 4.4 | ||
| 4.5 | 4.8 | ||||
| 50X114 | S5 | 2.3 | 2.5 | ||
| 2.7 | 2.9 | ||||
| 50X152 | S5 | 3 | 3.3 | ||
| 3.5 | 3.8 | ||||
| 50X228 | S5 | 4.4 | 4.8 | ||
| 5.2 | 5.7 | ||||
| 76X228 | S5 | 5 | 5.4 | ||
| 5.8 | 6.6 | ||||
| 46X150 | LAM G8 | 3.4 | 3.7 | ||
| 4.1 | 4.7 | ||||
| 46X231 | LAM G8 | 4.7 | 5.1 | ||
| 5.6 | 6.5 | ||||
| 70X231 | LAM G8 | 5.4 | 5.8 | ||
| 6.4 | 7.8 | ||||
| 79×297 | LAM G8 | 6.9 | 7.4 | ||
| 8 | 9.5 | ||||
Guideline Span Table for SA Pine Floor Beams
- Point load 1.5kN – Deflection criteria L/300
- Total floor load 1/5kN/sqm – Dead load 0.75kN/sqm – Live load 0.75kN/sqm
- 22mm T&G flooring 0.11 kN/sqm and Ceiling 0.14 kN/sqm dead load included
- 32mm T&G flooring 0.15 kN/sqm and Ceiling 0.14 kN/sqm dead load included
- Domestic use, for Commercial loading a Rational Design will be required!
- (NOTE: Deflections have been limited to 13mm region!)
| FLOOR JOISTS | 22mm T&G flooring 22mm Pine Decking | 32mm T&G flooring | |||
| Joist Spacings | 400 | 450 | 500 | 600 | |
| SECTION | GRADE | MAX. SPAN | |||
| 38X228 | S5 | 4.4 | 4.2 | 4.0 | 3.7 |
| 50X228 | S5 | 4.7 | 4.5 | 4.3 | 4.2 |
| 76×228 | S5 | 5.0 | 4.9 | 4.8 | 4.8 |
| 46X231 | LAM G8 | 4.8 | 4.7 | 4.6 | 4.6 |
| 46×297 | LAM G8 | 5.8 | 5.7 | 5.5 | 5.5 |
Guideline Span Table for SA Pine Beams - Tiles
- WIND CATEGORIES: B, C and D
- Tables valid for Simply Supported Beams only
- Min. rafter pitch for tiles 17.5 deg. using a 38×38 tile batten @ 320mm centres.
- Guideline Support Beam span Table for Tiles
Tiles Table - with ceiling
| Incoming Rafter Span | Beam Span 2m | Beam Span 3m | Beam Span 4m | Beam Span 5m | Beam Span 6m | Beam Span 7m | Beam Span 8m |
| 2 m | 38X152 (S5) | 38X228 (S5) | 76X228 (S5) | 45X297 (G8) | 70X297 (G8) | 70X363 (G8) | 70X396 (G8) |
| 3 m | 38X152 (S5) | 50X228 (S5) | 76X228 (S5) | 70X297 (G8) | 45X363 (G8) | 70X396 (G8) | 106X396 (G8) |
| 4 m | 38X228 (S5) | 76X228 (S5) | 45X297 (G8) | 70X297 (G8) | 70X363 (G8) | 106X396 (G8) | 106X495 (G8) |
| 5 m | 38X228 (S5) | 76X228 (S5) | 70X297 (G8) | 70X363 (G8) | 106X363 (G8) | 106X495 (G8) | 106X495 (G8) |
| 6 m | 38X228 (S5) | 46X297 (G8) | 70X297 (G8) | 70X363 (G8) | 106X363 (G8) | 106X495 (G8) | 106X495 (G8) |
Guideline Span Table for SA Pine Beams - Sheeting
- WIND CATEGORIES: B, C and D
- Tables valid for Simply Supported Beams only
- Min. rafter pitch for sheeting 10.0 deg. using a 50×76 sheeting purlin @ 1,200mm centres.
- Guideline Support Beam span Table for Sheeting
Tiles Table - with ceiling
| Incoming Rafter Span | Beam Span 2m | Beam Span 3m | Beam Span 4m | Beam Span 5m | Beam Span 6m | Beam Span 7m | Beam Span 8m |
| 2 m | 38X114 (S5) | 38X152 (S5) | 38X228 (S5) | 50X228 (S5) | 46X297 (G8) | 70X231 (G8) | 70X297 (G8) |
| 3 m | 38X152 (S5) | 50X225 (S5) | 50X228 (S5) | 76X228 (S5) | 46X297 (G8) | 70X297 (G8) | 70X363 (G8) |
| 4 m | 38X152 (S5) | 38X228 (S5) | 76X228 (S5) | 46X297 (G8) | 70X297 (G8) | 70X363 (G8) | 70X396 (G8) |
| 5 m | 38X228 (S5) | 50X228 (S5) | 76X228 (S5) | 70X297 (G8) | 70X297 (G8) | 70X363 (G8) | 70X396 (G8) |
| 6 m | 38X228 (S5) | 50X228 (S5) | 46X297 (G8) | 70X297 (G8) | 70X363 (G8) | 70X363 (G8) | 106X396 (G8) |
Timber & laminated beam descriptions & grades
SA PINE: GRADE S5
SECTIONS: 38X38, 38X50, 38X76, 38X114, 38X152 & 38X228 50X76, 50X152 & 50X228 76X228
LENGTHS: 3,000, 3,600, 4,200, 4,800, 5,400, 6,000 & 6,600
LAMINATED BEAMS: – GRADE G8
SECTIONS: 46X150, 46X231, 46X297, 70X231, 70X297, 70X363, 106X363
LENGTHS: 6,000, 6,600, 7,200, 7,800, 8,400, 9,600, 10,200 & 12,000.
WIND CATEGORIES: Reference: SANS 10160-3 (6.3.2.2):
CATEGORY A: Flat Horizontal terrain with negligible vegetation and without any obstacles (for example coastal areas exposed to open sea or large lakes.)
CATEGORY B: Area with low vegetation such as grass and isolated obstacles (for example trees and buildings) with seperations of at least 20 obstacle heights.
CATEGORY C: Area with regular cover of vegetation or buildings or with isolated obstacles with seperations of max. 20 obstacle heights (such as villages, suburban terrain and permanent forest.)
CATEGORY D: Area in which at least 15% of the surface is covered with buildings and their average height exceeds 15 m.
INDEMNITY: – The relevant specification table is furnished for guidance purposes only and we Peter Allan Building Materials Trust t/a Peter Allan Timber do not accept any liability whatsoever should you rely on same.
