Structure: Approved Document A

O N L I N E V E R S I O N A1/2 THICKNESS OF WALLS IN CERTAIN SMALL BUILDINGS Diagram 14 Sizes of openings and recesses See para 2C29 8 Take the value of the Factor X from Table 8, or it can be given the value 6, provided the declared compressive strength of the bricks or blocks (in the case of a cavity wall – in the loaded leaf) is not less than 7.3N/mm2. Table 8 V alue of Factor ‘X’ (see Diagram 14) Span of timber Span of concrete floor into wall floor into wall Span of floor Minimum is parallel max max max max Nature of Maximum thickness of to wall 4.5m 6.0m 4.5m 6.0m roof span roof span (m) wall inner (mm) Value of Factor ‘X’ Roof spans Not 100 6 6 6 6 6 parallel to wall applicable 90 6 6 6 6 5 Timber roof 9 100 6 6 5 4 3 spans into wall 90 6 4 4 3 3 Table 9 L ateral support for walls Wall type Wall length Lateral support required Solid or cavity: external Any length Roof lateral support by every roof forming a junction with the compartment separating supported wall Greater than 3m Floor lateral support by every floor forming a junction with the supported wall Internal load-bearing wall (not being Any length Roof or floor lateral support at the top of each storey a compartment or separating wall) Approved Document A Structure O N L I N E V E R S I O N 29