AS 1170.3-1990

1 - AS 1170.3-1990 SAA LOADING CODE - SNOW LOADS
4 - PREFACE
5 - CONTENTS
6 - SECTION 1. SCOPE AND GENERAL
6 - 1.1 SCOPE
6 - 1.2 APPLICATION
6 - 1.3 REFERENCED DOCUMENTS
6 - 1.4 METHODS OF DETERMINATION OF SNOW LOADS
6 - 1.5 LOAD COMBINATIONS
6 - 1.6 NOTATION
8 - SECTION 2. GEOGRAPHIC REGIONS AFFECTED BY SNOW
8 - 2.1 REGIONS WITH SIGNIFICANT SNOWFALLS
8 - 2.2 DIVISION OF REGIONS
10 - SECTION 3. SNOW LOAD IN SUB-ALPINE REGIONS
10 - 3.1 DETERMINATION OF GROUND SNOW LOAD
10 - 3.1.1 Introduction.
10 - 3.1.2 Ground snow load.
10 - 3.2 SNOW WEIGHT.
10 - 3.3 DETERMINATION OF SNOW LOAD ON BUILDING SURFACES
10 - 3.3.1 Flat and unobstructed sloping roofs
10 - 3.3.2 Obstructed sloping roofs
10 - 3.3.3 Drifting snow
10 - 3.3.4 Curved roofs
15 - SECTION 4. SNOW LOAD IN ALPINE REGIONS
15 - 4.1 DETERMINATION OF GROUND SNOW LOAD
15 - 4.1.1 Introduction
15 - 4.1.2 Terrain classification
15 - 4.1.3 Ground snow load
16 - 4.1.4 Snow weight
17 - 4.2 DETERMINATION OF SNOW LOAD ON BUILDING SURFACES
17 - 4.3 EXPOSURE TO WIND
17 - 4.4 ROOF SLOPE
17 - 4.4.1 Effect of roof slope on monoslope, gable and hip roofs
17 - 4.4.2 Effect of roof slope on curved roofs
17 - 4.4.3 Effect of roof slope on single and multi-span roofs with valleys
17 - 4.5 PARTIAL LOADING
17 - 4.6 UNBALANCED SNOW LOAD
17 - 4.6.1 General
17 - 4.6.2 Unbalanced snow load for hip or gable roofs
17 - 4.6.3 Unbalanced snow load for curved roofs
17 - 4.6.4 Unbalanced snow loads for single and multispan roofs with valleys
21 - 4.7 DRIFTS ON LOWER ROOFS OR OTHER SURFACES
24 - 4.8 ROOF PROJECTIONS
25 - 4.9 SLIDING SNOW
25 - 4.10 SNOW CREEP
26 - APPENDIX A - EFFECTS OF TERRAIN ON THE DISTRIBUTION OF GROUND SNOW LOAD IN ALPINE REGIONS
26 - A1 INTRODUCTION
26 - A2 FACTORS AFFECTING GROUND SNOW DISTRIBUTION
26 - A2.1 Mechanism of snow formation
26 - A2.2 Mechanism of ground snow distribution
26 - A3 GROUND SNOW DISTRIBUTION
28 - APPENDIX B - COMMON PROBLEMS AND THEIR AVOIDANCE
28 - B1 ROOF SLOPE AND SHEDDING SNOW
28 - B2 ROOF SHEETING SLIDING OFF THE ROOF
28 - B3 INGRESS OF SNOW UNDER RIDGE CAPPING
29 - B4 SLOPED VALLEYS IN ROOFS
29 - B5 EAVES GUTTERS
29 - B6 VENTILATION OPENINGS
30 - B7 BUILDING LOCATIONS
30 - B8 VENTS ON ROOFS
31 - B9 VERTICAL PROJECTIONS

This Standard sets out data and procedures for determining minimum snow loads on roofs, balconies, walkways, and other building surfaces, in areas which receive significant snowfalls. It also provides guidance on the avoidance of common problems which occur mainly in alpine regions.

This Standard sets out data and procedures for determining snow loads to be used in structural design.

Under Revision see DR 01218