Structure: Approved Document A

O N L I N E V E R S I O N A CONTENTS PAGE PAGE DIAGRAMS TABLES 1. S ize and proportion of residential 1. A reas at risk from house buildings of not more than three storeys 14 longhorn beetle 12 2. Size and proportion of non-residential 2. Wall types considered in this section 13 buildings and annexes 15 3. Minimum thickness of certain 3. Determination of wall thickness 16 external walls, compartment walls and separating walls 16 4. Parapet walls: height 17 4. Imposed loads 18 5. Maximum floor area enclosed by structural walls 18 5. Cavity wall ties 23 6. M ap showing wind speed in m/s for 6. Declared compressive strength of maximum height of buildings 19 masonry units complying with BS EN 771-1 to -5 25 7. Maximum height of buildings 21 7. Normalised compressive strength of 8. Measuring storey and wall heights 22 masonry units of clay and calcium 9. D eclared compressive strength of silicate blocks complying with masonry units 24 BS EN 771-1 and -2 25 10. Maximum span of floors 25 8. Value of Factor ‘X’ 29 11. Differences in ground levels 26 9. Lateral support for walls 29 12. Openings in a buttressing wall 27 10. Minimum width of strip footings 37 13. Buttressing 28 11. Building consequence classes 44 14. Sizes of openings and recesses 29 15. Lateral support by floors 30 16. Lateral support at roof level 31 17. Size and location of openings 32 18. Wall thickness 33 19. Lateral restraint at roof level 34 20. Proportions for masonry chimneys 35 21. Elevation of stepped foundation 36 22. Piers and chimneys 36 23. Foundation dimensions 36 24. Area at risk of collapse in the event of an accident 45 Structure Approved Document A 2 O N L I N E V E R S I O N