Consolidation is a vital part of the work that the Vindolanda Trust undertakes to maintain and conserve Roman Vindolanda, part of the UNESCO World Heritage Site of Hadrian's wall. The Vindolanda Trust looks after the site with its own dedicated consolidation mason and archaeological team.This work is entirely funded by the contributions of visitors who come to the site and receives no state or public funding.

Two types of consolidation take place at the site of Vindolanda.

First time consolidation:

Once a building has been uncovered, normally by archaeological excavation and research, it is very carefully mapped out and the position of each stone is marked to the nearest millimetre through a combination of total station planning and photogrammetry. This enables the archaeologist to make an accurate 3D scan of walls, floors and features that can be manipulated and viewed from any angle. This information is then taken by a consolidation architect to carefully map out a strategy for mortar mixes, core work and replacement stones for any parts of the structure that may be in danger of collapse. 

The plan of works is then submitted by the Vindolanda Trust to Historic England in an application for a SMC (Scheduled Monument Consent) or permission to carry out the work by a qualified Heritage or consolidation mason. Once the scheme is passed and permission is granted for the work the consolidation mason uses this extremely detailed brief to conserve the buildings so that they might survive to be enjoyed by future generations.  

Where possible standing walls are merely raked out and repointed using a lime-based mortar mix. The lime used has a low strength so that is does not damage the Roman stones by sticking to them too well. Some stones are cut out and replaced in this process if they are too badly worn or damaged to remain exposed and in those cases all the stones are replaced by fallen Roman stones, carved in a period contemporary to the building being work on. In all cases the character and integrity of what has been found must be respected. 

Because the masons use lime, the consolidation team can only work in temperatures above 6-7 degrees Celsius therefore the work has to take place in the summer months. Roman masons were not as fussy at Vindolanda and worked in all weathers but they did have the added advantage of sealing their work with roofs, something that the modern masons can no longer do. 

At Vindolanda our Consolidation mason, Dan, has over a decade of experience working with stone and he is currently working on the south eastern quadrant of the last stone fort. 

Re-Consolidation:

Just like a normal house, through time all masonry at the site requires attention. Mortar will eventually fail or drop out and work carried out in the 1970's - 1990's needs to be re-done as techniques and conservation has changes a great deal in modern times. The Vindolanda Trust hopes for at least 20-25 years for the success of first-time consolidation with minor repairs in that period. However, after 25 years it expects that more major interventions may be required to maintain the integrity of the monument. 

What do we not do?

Re-build or build up beyond the height encountered in excavation. All of Vindolanda is preserved 'as found'. When you see a consolidation mason working, they are not re-building the site or adding anything new to it.