12PS.1
1. WORLD MONUMENTS FUND
The “Churning of the Sea of Milk” gallery in Angkor Wat temple is not affected by any structural problem, the ongoing threat for conservation of the bas-relief being from rainwater penetration and the migration of salts. The WMF has prepared a well-founded project supported by thorough documentation, tests and a structural analysis. The philosophy advocated by this operator is good and could be described as “preventive measures to prevent damage and decay”. However, due to the fact that there is no immediate risk (the decay process is very slow), it is suggested that further analytical thinking be done on three main points:
- The insertion of lead sheets between the joints needs to be experimentally evaluated because it could reduce friction and therefore introduce an element of risk as far as the structural conditions are concerned;
- Cultural aspects. It has been repeated on numerous occasions that dismantling and rebuilding should be a very exceptional measure to be undertaken only where an alternative solution is not possible or reliable.
- Future benefits. Whenever possible, any undertaking should be an opportunity to acquire experience that can be used in similar work, with obvious benefits from the standpoint of economics and technology.
Based on these observations, it is suggested that the following laboratory and on-site testing and analysis work be carried out:
- Establish the actual extent of salt brought on by the presence of cement in this gallery;
- Establish the friction coefficient of lead sheeting on sandstone;
- Measure the tilting of the pillars in the gallery and inclination of “horizontal” points;
- Determine the amount of water penetrating through all the roofs of the gallery;
- Make a test on a limited area to be defined by APSARA, in order to verify the feasibility and relevance of the solution proposed by WMF;
- Carry out further theoretical and experimental research to look for alternative solutions to ensure impermeability that do not require the systematic dismantling of dry masonry.
Based on the results obtained from the aforementioned tests and studies, it is also recommended that alternative solutions for waterproofing be explored for all the roofs of Angkor temples, to be presented during a special site workshop to be held prior to the next ICC Technical Committee.