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Masonry and Cement

The complex is predominantly constructed of limestone, both locally sourced and from Rottnest Island. It also incorporates brickwork. The stone ranges from poor-to-good condition but is often severely decayed where in close proximity to cement renders and mortars.


The houses fronting the Terrace and the Hospital have been rendered in a cement-based system. It appears that part of the building has been re-rendered at various times and that the newer renders are more cementitious than the earlier composite render system. This is generally undesirable.


There are also white washes and other treatments throughout the complex.

SPECIFIC POLICY 36: Fremantle Prison should observe a process of repair, conservation and monitoring of all masonry. All masonry elements should be maintained in good condition.


SPECIFIC POLICY 37: Cement-based mortars and renders should be removed and avoided.

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SPECIFIC POLICY 38: Where rendered finishes are identified as dating to an early period, and where they contribute to the heritage values of the particular building, they may be retained. If it is necessary to remove these renders as a result of decay of the limestone substrate, consideration could be given to lime putty based render systems as an appropriate substitute for cement. Be aware that lime putty and cement are incompatible. Portland cement was readily available in Australia from 1850 onwards and was manufactured in Melbourne in the early 1850s.


Therefore, historically other types of cementitious-based renders or Roman cement may exist and, subject to petrographic analysis or XRF (X-ray fluorescence) analysis, the decision making process should be based on compatibility with what is existing (early or original) and the performance of the substrate.

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SPECIFIC POLICY 39: Some renders contain graffiti and other art works that contribute to the Prison’s significance. Do not remove those renders without first assessing the heritage values embodied by the graffiti and artwork. This will need to be assessed on a case-by-case basis. For example, in some circumstances it will be appropriate to remove render with graffiti of local significance to conserve underlying walls that embody Outstanding Universal Value.

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SPECIFIC POLICY 40: Where it is proposed to retain renders to conserve identified heritage values consider the use of chemical consolidation, poultices and alternative repair methods to stabilise the masonry substrate.

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SPECIFIC POLICY 41: Review white washes and other treatments to ensure that they are consistent with assessed heritage values. Evidence of these exist through out the complex.

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SPECIFIC POLICY 42: A cautious approach should be adopted in any repair work, and investigations into methods should be carried out prior to reversal.

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SPECIFIC POLICY 43: Reinstate original pointing treatments, such as tuck pointing, scribed ashlar lines or other expressed detail which is no longer apparent. In doing so, it is important to understand the architectural presentation of the buildings, with mortar for pointing to be expressed or scribed to represent ashlar line works.

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SPECIFIC POLICY 44: New mortar repairs should differ in composition to the pointing mortar and should be coloured to match the limestone. This would provide a better architectural understanding of individual blockwork. The current approach is to use the same mortar to repair the stone and repoint, which is a much brighter white than the stone, resulting in a rendered appearance.

SPECIFIC ACTION 28: Continue the current programme of removing cement-based mortars and renders and repoint the limestone in lime-based mortars. The lime-based mortar is to be sacrificial and will require a maintenance regime with a frequency informed by monitoring.

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