Masonry diaphragm walls are an alternative means of constructing
tall, single storey buildings such as warehouses, sports centres,
churches, assembly halls, etc. They can also be used as retaining
and boundary walls with planting potential within the voids. These
voids may also be steel reinforced and concrete filled to resist the
lateral stresses in high retaining walls.
A diaphragm wall is effectively a cavity wall where the two leaves
of masonry are bonded together with cross ribs and not wall ties.
It is stronger than a conventionally tied cavity wall and for
structural purposes may be considered as a series of bonded `I'
sections or box sections. The voids may be useful for housing
services, but any access holes in the construction must not disturb
the integrity of the wall. The voids may also be filled with
insulation to reduce heat energy losses from the building, and to
prevent air circulatory heat losses within the voids. Where thermal
insulation standards apply, this type of wall will have limitations
as the cross ribs will provide a route for cold bridging. U values
will increase by about 10% compared with conventional cavity wall
construction of the same materials.
Ref. BS 5628-1: Code of practice for use of masonry. Structural use
of unreinforced masonry.
BS 5628-3: Code of practice for use of masonry. Materials and
components, design and workmanship.
Masonry Diaphragm Walls