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AFS LOGIC WALL RELIES ON THE UNISEARCH REPORT (refer
Appendix)
FOR AS3600 COMPLIANCE
Engineers, architects and certifiers should read the following
to decide if AFS LOGIC WALL can satisfy the following requirements
of UNISEARCH.
1. AFS Logic Wall must be protected and maintained
adequately
The requirement of Unisearch is shown in the adjacent diagram.
The membrane shown must be used and maintained. Questions to ask
are:
(i) What is the life of the membrane system? 10 years or20
years? AS3600-2009 requires a structural life of 50years +/- 20% =
60 years.
(ii) Who will provide 60 years warranty for a
membranesystem?
(iii) If the life of the membrane system is, say 20 years,
themembrane paint must be repeated at least 3 times tosatisfy the
60 years structural life. Who will do thismaintenance during the
life of the structure sinceAustralia has no law to enforce the
maintenance of amembrane system on a building wall?
2. Metal channels should not corrode
Lightly galvanised sheets for the manufacturing of metal
channels are bent to form, cut,punched, and screwed on site. Hence,
galvanising of the AFS metal channels are significantlycompromised.
This condition of the metal channels therefore does not satisfy
Unisearch’srequirement, i.e. metals with compromised galvanising
must have concrete cover or membraneprotection. For further
information and photos refer to (download) AS3600
DurabilityCompliance Assessment of AFS Logic Wall.
3. Unisearch states that if Items 1 and 2 are satisfied, AFS
Logic Wall can be said tocomply with the “deemed to satisfy”
condition of the BCA.
It appears that the writer of the Unisearch Report is not aware
or ignores the AS3600-2009Commentary shown in the Appendix (refer
highlighted paragraphs). The AS3600-2009Commentary clearly states
that systems that rely on coating systems (such as membranesystems
of the AFS Logic Wall) are outside the scope of AS3600-2009.
In fact, the statement “AFS Wall must be protected and
maintained adequately” contradictsAS3600 since AS3600 is not
written for solutions based on protective systems. AS3600
onlyrelies on the concrete cover and nothing else.
Therefore, AFS Logic Wall cannot be said to comply with the
“deemed to satisfy”condition of the BCA which is AS3600-2009.
http://www.dincelandassociates.com/documents/AS3600%20Durability%20Compliance%20Assessment%20of%20AFS%20Logic%20Wall.pdfhttp://www.dincelandassociates.com/documents/AS3600%20Durability%20Compliance%20Assessment%20of%20AFS%20Logic%20Wall.pdf
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BASED ON THE ABOVE, QUESTIONS TO THE:
Builder/Developer Check if your building is insurable if the
structure does not comply with AS3600 and displaying corrosion and
mould/mildew?
Engineer/Architect/Certifier For further explanation Engineers
can refer to (download) AFS Logic Wall Structural Engineering
Assessment.
Can the engineer override the AS3600 Commentary and the photos
shown in the Appendix? Is the specifier prepared to accept the
responsibility for any consequences as a result of ignoring
AS3600-2009 Commentary?
Installer Formworks consisting of fibre cement sheets are
similar to besser blocks which are required to be wetted first and
then 230mm concrete slump is used.
Otherwise as shown in Photo No: 1 of the Appendix air voids are
not avoidable.
What would be your answer if you are accused that the air voids
are an installation problem – not a product problem due to the use
of fibre cement sheets as formwork?
The above issue is relevant to both internal and façade walls as
AS3600 requires maintenance free system by the provision of
concrete cover, not membrane protection, for both cases. AS3600 is
clear that membrane system protection is not allowed.
It is recommended that the following statements should be
obtained from the engineer/installer to protect the
Certifier/Builder/Developer:
Structural Engineer:
“I acknowledge that AFS Logic Wall requires to be protected by a
water/air proof membrane system to be maintained for a minimum of
60 years structural life. I further acknowledge that the AS3600 –
2009 commentary states that protection by a membrane system is
outside the scope of AS3600”.
Installer:
“I acknowledge that fibre cement sheets, like besser blocks, are
porous in nature hence require wetting the forms prior to
concreting and using high slump concrete to avoid the occurrence of
air voids. I therefore confirm that AFS Logic Wall having fibre
cement sheets concrete filled by us shall not have air voids in
them”.
http://www.dincelandassociates.com/documents/AFS%20Logic%20Wall%20Structural%20Engineering%20Assessment.pdfhttp://www.dincelandassociates.com/documents/AFS%20Logic%20Wall%20Structural%20Engineering%20Assessment.pdf
