England · Statutory guidance
Structure: Approved Document A
Guidance on structural loading, foundations, walls, floors, roofs and disproportionate collapse.
- Edition
- 2004 edition incorporating 2010 and 2013 amendments
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- 54 of 54 PDF pages · 1 OCR pages
Structure
Open original PDF at page 22 Source wording and page order preserved. Drawings and table layouts remain available in the original PDF.
A1/2
THICKNESS OF WALLS IN CERTAIN SMALL BUILDINGS
Diagram 6 Map showing wind speeds in m/s for maximum height of buildings
-1
Structure Approved Document A
20
O
rotcaF
yhpargorO
1.40
1.35
Steep slope < 1/3.3
1.30
1.25
Moderate slope = 1/5
1.20
1.15
1.10
Shallow slope ≤ 1/10
1.05
1.00
-0.5 0 0.5 1 1.5
X/Lu X/Ld
Figure 3a Orography Factor O for hills and ridges
-1
Figure 3b Orography Factor O for cliffs and escarpments
(interpolation between curves may be used)
Figure 3 Alternative graphical method for determining Orography Factor O
O
rotcaF
yhpargorO
O N L I N E V E R S I O N
0.5Ld
Orography
0.5z significant in
z shaded area
-X +X
Lu Ld
1.40
1.5Ld
1.35
0.5z
Steep slope < 1/3.3 z
1.30 Orography
-X +X significant in
Lu shaded area
1.25
1.20
Moderate slope = 1/5
1.15
1.10
1.05
Shallow slope ≤ 1/10
1.00
-0.5 0 0.5 1 1.5 2 2.5
X/Lu
O N L I N E V E R S I O N
Edition and local adoption determine which requirements apply. Use the publisher’s document for the complete clauses, diagrams and amendments.