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BUILDING CONNECTION
SUMMER 2016 15
The Deemed-to-Satisfy referenced construction manual,
which in most cases is the BCA referenced Australian
Standard relevant to the construction, is assessed as being
compliant. AS 3740-2010 is the document, in this case.
Where a Performance Solution is provided, the appointed
certifier must independently READ and ASSESS the
documentary evidence provided as being compliant with the
Performance Provisions.
However, the Performance Provisions are the premium
factor that all Building Solutions must lead back to and
comply with.
Under BCA Vol 2 Part 2.4.1, the Performance Provisions
are:
“To protect the structure of the building and to maintain
the amenity of the occupants, water must be prevented
from penetrating
a. behind fittings and linings; or
b. into concealed spaces of sanitary facilities, bathrooms,
laundries and the like “
STEPS TO DETERMINE MATERIAL SUITABILITY
Following are the steps required in order to assess
the BCA requirements and marry these up with material
suitability, when considering the use of a material such as
welded vinyl in wet areas.
1. BCA states that wet areas are to be made waterproof
or water resistant according to AS 3740 – 2010. A
waterproof material is one that is impervious to liquid
passing through it, such as a glass panel, a receptacle
like a bath or basin, and a waterproof membrane. Water
resistant materials are those that restrict the passage
of water and do not deteriorate when in contact with
moisture. Materials such as ceramic tiles, mortar
screeds, cement based tile adhesives and concrete
are classified as water resistant and are used as lining
materials and intermediate layers acting as ballast and
drainage cells.
2. BCA Table 3.8.1.1, and AS 3740 Table C1 prescribe the
designated wet areas and the components of those wet
areas requiring treatment as either waterproof, water
resistant, or no treatment required. The scheduled wet
areas are:
a. Showers
b. Areas adjacent to baths and spas (Bathrooms, ensuites,
powder rooms etc.)
c. Laundries
d. Toilets
3. Components in the above wet areas are broken down and
a level of protection assigned according to the usage
of that area and the regularity of exposure to water
and water movement. All shower floors and horizontal
surfaces are required to be waterproof. Shower walls are
3:
Waterproof membrane to floor and critical wall areas of
shower. Water resistant wall substrate to shower walls.
4:
Water damage to non-compliant skirting. All compliant
substrate and lining materials must be in conjunction.
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required to be waterproof only up to 150mm from the floor
with the remainder being water resistant to a minimum of
1800mm from FFL as determined by the rose connection.
Shower wall joints are to be waterproof.
Bathroom, laundry and toilet floors are required to be
water resistant, when on concrete or FC sheeting, and
waterproof when on timber substrate. Wall and floor
junctions are required to be waterproof and sealed to
a water stop at doorways as part of the continuous
perimeter flashing.
4. AS 3740 Section 2 lists compliant materials which
are classified as either waterproof or water resistant.
Section 2.4.2 lists substrate materials that are water
resistant, when used in conjunction with compliant lining
materials. Section 2.4.3 lists compliant lining materials
when used in conjunction with compliant substrate