46 / 116
4 6
PLUMBING CONNECTION
SUMMER 2016
A SLAB OF CONFUSION
T
he term ‘reactive soil’ may conjure up images of
radioactivity beneath the earth’s surface, however
reactive doesn’t indicate that the soil is contaminated
in any way, rather; it refers to the way it reacts to changing
moisture content.
All clay-based soils have the potential to change volume
and shift with changes in the amount of moisture in the soil
- and are sometimes called ‘reactive soils’ because of this.
The amount that soil is likely to shift defines how ‘reactive’ it
is considered to be.
Some soils have a greater potential to change volume than
others, and this amount of potential needs to be measured
with a soil test to make sure footings are designed in a
way that helps protect it from soil movement that might
otherwise cause it to sink or buckle.
So, while it is often assumed that homes are built on solid
ground... this may not always be the case.
RESEARCH
The issue of reactive soils is a national one though it really
came to the fore in Victoria during the drought that ran
from 1996-2009 with new homes that were experiencing
settlement. Rain wasn’t falling, grounds were excessively dry
and as a result, soils contracted and walls began to crack.
And then the rains came, bringing with it myriad other issues.
Swinburne University has been conducting research
in the area of reactive soils to try and better predict the
performance of houses and how we as a nation can improve
house and plumbing designs that better resist moving.
A consortium was formed including the Victorian Building
Association (VBA), Office of Housing, the Association of
Consulting Structural Engineers Victoria (ACSEV), the
Foundation and Footings Society Victoria (FFSV), Housing
Engineering Design & Research Association (HEDRA) and
Swinburne University.
THE TYPE OF EARTH THAT FOUNDATIONS ARE LAID ON CAN HAVE REPERCUSSIONS FOR YOUR CLIENT’S
DWELLINGS AND THE PLUMBING AND DRAINAGE SYSTEMS THAT SERVICE THEM.
PLUMBING CONNECTION
INVESTIGATES THE ISSUE OF REACTIVE SOILS AND WHAT MEASURES TO TAKE TO ENSURE PLUMBING SYSTEMS
STAND UP TO THE FORCES OF MOTHER NATURE.
REACTIVE SOIL