Our Humble Heritage workshops are a new series designed to give delegates a thorough theoretical and technical basis of knowledge about a subject, reinforced with guided practical, hands-on experience.

On this course delegates will learn about the following:

• Lime cycle
• Traditional Building Technology
• How to attain effective porosity and capillarity
• SPAB philosophy of repair and best practice conservation principles
• How to select, prepare, and apply earth-lime and hot mixed lime mortars
• How to safely remove cementicious mortars with minimal damage to historic fabric
• The different types of lime and the advantages, as well as the historic ubiquity of earth, earth-lime and hot mixed air lime mortars, modified as necessary and according to purpose and situation with traditional pozzolanic addition – such as wood ash, brick dust, trass or smith’s forge ashes.
• The problems associated with NHLs
• Traditional and modern hot mixing methods, focussing on how long it takes to ‘cook’
• How to deep-pack with earth-lime mortars, if these are discovered to have been the original mortars of construction.

On the Thursday evening of the course, two lectures will be given on the rudiments of traditional building technology and the importance of effective porosity and capillarity, and how this is ensured and maintained by the mortars, as well as of the SPAB philosophy of repair and best practice conservation principles generally, with particular emphasis upon like-for-like and compatible repair and conservation.

The hands-on training will focus on the techniques of removing harmful cement renders with minimal damage to historic fabric, and using like-for-like repair that will demand either earth-lime or hot mixed lime mortars, or a combination of both.

Delegates will finish the course with a clear understanding of how to source local materials, prepare and use hot mix lime mortars, remove cement render with minimal harm to historic material and have gained a deeper understanding of why traditional mortars are a suitable material for their compatibility and their potential role in the mitigation of climate chaos.