Heritage services and mortar testing

Stone Initiatives specialises in the testing and evaluation of building stone and related materials such as historical coatings, mortar and cement products. Working alongside heritage architects, we carry out trials and perform a range of on-site and in-lab testing.

Our heritage services include:

  • Consultation
  • Mortar compositional analysis
  • On-site testing
  • Laboratory testing
  • Diagnostics
  • Treatment recommendation – for restorable materials
  • Material matching – material replacement
  • Preventative conservation
  • Research projects
  • Failure analysis
  • (see more extensive list at bottom of page).

The Burra Charter and heritage consultants

The Burra Charter outlines the basic principles and procedures to be followed in the conservation of Australian heritage places. Conservation should be based on a respect for the existing fabric and should involve the least possible physical intervention. There should be no new construction, demolition or modification that would adversely affect the setting, or the appreciation and enjoyment of the place.

Our approach

Stone Initiatives does “as little as possible but as much as is necessary” to responsibly conserve heritage structures. Working alongside heritage architects, we carry out trials and perform a range of on-site and in-lab testing. We also determine the most suitable cleaning and restoration methodologies for the individual project.

Failure analysis for historical building materials

Like all building materials, dimension stone is subject to failure through improper use, installation or maintenance. The identification of the cause of such failures is important to avoid recurrence of the problem. Stone Initiatives has expertise in the field of failure analysis. We assist clients to determine the causes of failures in a wide range of materials, structures and locations. We also assist in the development and trialling of suitable rectification methods. These may include investigations to select a suitable consolidant, cleaning method or matching and repair of historical materials.

Our heritage consultancy services are carried out in Adelaide, Sydney, Melbourne, Brisbane and around Australia. You can send samples to our NATA-accredited lab here in Adelaide. Get in touch to discuss how we can help restore your historical structure or support your conservation plan.

Above: Stone Initiatives is working with the stone mason on the Maxwell Plaque of the Adelaide’s Clayton Wesley Church, to determine stone type and provenance as well as the most appropriate method of stabilising the stone to minimise further deterioration. 

Mortar testing

Testing and evaluation of mortar and render samples provides data to not only determine the suitability of the sample for proposed uses, but also to enable us to compare and reproduce as closely as possible to the original mortar or render used, therefore faithfully conserving the heritage value of the building. Our team assists owners, architects and conservators in developing the knowledge necessary to produce an informed conservation plan. We also test to confirm compliancy of the masonry with the requirements of the Building Code of Australia and AS3700 (Masonry Code).

Tests include:
Bulk and Clay X-Ray Diffraction Mineralogy analysis of crystalline components
Cement / Lime / Sand content
Moisture Content
Total Dissolved Salt (Conductivity)
Sand sizing (grain size distribution)
Aggregate colour & morphology
Determination of Clay content

Moisture surveys

Salt damp is particularly prevalent in Adelaide due to shallow underground streams and high salt content within the soils. Many of the city’s original buildings were constructed with a hot-laid bitumen damp course at the base to protect it from rising damp. Over time the bitumen breaks down and allows moisture to rise. Stone Initiatives has carried out many moisture surveys on heritage buildings with rising damp issues in Adelaide, and around Australia.

A moisture survey is one method that can be used to detect rising damp or salt damp in a building – potentially dangerous problems that are common in heritage structures. A moisture survey is a non-destructive survey performed using a moisture meter, typically in a grid over the area affected by rising damp. Moisture values are plotted and a “heat map” is produced, often showing the extent of damp and sometimes epicentres and sources of moisture. 

The aim of a moisture survey is to detect the location, extent and sources of the moisture. A moisture survey might be carried out in conjunction with salt content testing, X-ray diffraction testing and mortar analysis. With these tests, Stone Initiatives can help to determine the severity and extent of the problem, which can aid in developing a remediation plan with a professional builder or damp proofing specialist. Steps might include removing the source of moisture, installing a damp-proof course, re-plastering / re-rendering, desalination of the masonry, and ventilation. Stone Initiatives has performed investigations into rising damp issues at sites across Australia.

Are conservation plans important?

YES. Conservation plans are important because they minimise the risk of dilapidation or unintentional damage caused by ad-hoc conservation works. Further, they minimise the ill-informed use of building materials, consolidants, sealers, coatings and cleaning methods.

Determination of the material’s characteristics and physical properties allows the conservation plan to be based on informed decisions. This minimises the risk of damage or unnecessary deterioration. A responsible conservation plan requires wise management of resources and sound judgement to control the agents of deterioration and preserve the integrity of the monument.

And that is where we come in. Stone Initiatives assists owners, architects, conservators and the construction industry in developing the knowledge necessary to produce informed conservation plans. We are passionate about conserving historical sites and monuments. We know they improve our environment, connect us to our heritage and add to the community’s sense of belonging.

Why do I need a heritage conservation consultant?

Engaging a heritage consultant is a vital step in ensuring the longevity and integrity of your heritage structure. Stone Initiatives has the knowledge and experience needed to best preserve these important sites and protect them from unintentional harm. We assist in identifying the correct materials, consolidants, sealers, coatings and cleaning methods to be used on your project – avoiding irreversible damage. We also assist heritage architects and other parties to meet the general requirements of the Burra Charter.

Throughout the investigation process we often unravel fascinating stories about the heritage structures. Read more here …

“Preserving architectural heritage allows us to maintain connections with our past, culture and each other – giving them life into the future. But in order to care for all parts of a heritage structure, an informed conservation plan is needed. We support our clients to care for their heritage buildings and produce responsible conservation plans that minimise the risk of damage and unnecessary deterioration, which can sadly be the result of well-intentioned but ill-informed decisions relating to heritage conservation.”

— Mark Milevski, Materials Testing Specialist, Heritage Services

Our heritage services


  • Onsite observation and dilapidation survey
  • Determination of suitable mortar, render and coatings
  • Heritage fabric condition report
  • Sample collection

Mortar Compositional Analysis

  • XRD analysis for semi-quantitative identification of constituents
  • Determination of cement (pozzolan) / lime / sand content
  • Sizing of aggregate and microscopic examination to determine sand morphology
  • Determination of clay content
  • Recommendations for replacement mortar mixes

On-site Testing

  • Moisture survey: moisture mapping of building surfaces
  • Sorptivity: absorption pattern of heritage fabric
  • Salt damp detection: presence of soluble salt in heritage fabric

Laboratory Testing

  • Determination of mineral composition of mortars and coatings
  • Efflorescence analysis: salt type (XRD) and salt content (TDS)
  • Desalination progress eg TDS of poultice


  • Stone and mortar health: extent of deterioration and weathering
  • Weathering factors: rising / falling damp, salts, UV, human impact etc
  • Preparation of conservation plan

Treatment Recommendation – for restorable materials

  • Salt removal: poulticing, wet/dry cycling and vacuuming
  • Damp management: hardware repair and management
  • Intervention treatment: damp proof course and drainage diversion
  • Stone Treatment: consolidant characterisation and matching
  • Desalination progress eg TDS of poultice

Material Matching – material replacement

  • Compatibility testing: physical and chemical characteristics of matching new materials
  • Accelerated testing: accelerated weathering tests on new materials

Preventative Conservation

  • Ongoing site survey, integrated maintenance and management plan

Research Projects

  • Heritage related research projects
  • Investigation of traditional building materials
  • Specific material analysis and research

Failure Analysis

  • Investigation into material failure in restored heritage buildings

For past projects see the Project Involvement list and Project Highlights gallery.