Building Construction Handbook, Eighth Edition

*Min. compressive strength depends on building height and loading.

See Building Regulations AD A: Section 2C (Diagram 9).

cavity leaves to be not

less than 90 mm thick

cavity to extend at least

225 mm below the lowest dpc

outer leaf of selected

facing bricks

dpc

ground level

TRADITIONAL CONSTRUCTION

bricks and blocks

below ground level

to be of suitable

quality*

mass concrete

strip foundation

(1 : 3 : 6) 15 N/mm^2

cavity filling of weak

concrete to prevent

leaves of wall moving

towards each other as a

result of earth pressures

well compacted hardcore

mass concrete

ground floor slab

damp-proof

membrane

50 mm min. rigid insulation

floor screed

150 min.

brick outer leaf and

block inner leaf

dpc

(^150) min.
ground
level
ALTERNATIVE CONSTRUCTION
225 or 300 mm wide
blocks of 150 or
225 mm thickness
laid flat
mass concrete
strip foundation
(1 : 3 : 6) 15 N/mm^2
blocks below
ground level
to be of a
suitable quality*
ground floor
construction
as above
damp-proof
membrane
insulated cavity to be unbridged
except by wall ties, unless a
suitable dpc is used to prevent
the passage of moisture to the
inner leaf
Cavity Walls