Questions & answers

This is where we answer visitors’ most frequently asked questions: 

1. How long will the restoration of the Tiepolo fresco in the staircase take?

2. What are the main types of damage?

3. What are the estimated costs of the whole restoration?

4. Is the state of the fresco in the staircase really so bad, and what actions are currently being taken?

5. What will the fresco look like after the restoration?

1. How long will the restoration of the Tiepolo fresco in the staircase take?

It is expected that it will take till 2006.

2. What are the main types of damage?

The main damage, both in the staircase and in the Kaisersaal (Imperial Hall), is caused by the action of salts. Damp penetrating through the vaulting (water from fire-fighting operations, rain damage due to absent or leaky roofing) has led to an accumulation of magnesium and calcium sulphates in the layers near the surface.

3. What are the estimated costs of the whole restoration?

The approved budget for building costs shows a total of € 5.9 million.

4. Is the fresco on the staircase really in such a bad state, and what actions are currently being taken?

Viewed from a distance from the upper gallery of the staircase, the painting appears to be in a relatively good condition. On closer inspection, however, several patches are noticeable. These mainly represent salt efflorescences and salt veiling on the surface of the painting, but there are also darker areas caused in particular by sintering or mould.

However, the inspections carried out in 1995 showed that the state of the paint layers and the support layers consisting of lime-mortar plaster was much worse in places than had been thought. Areas of the painting are only attached in the form of powdered or flake-like particles of pigment to the plaster support. Preparation of a comprehensive restoration was therefore immediately started. More intensive analyses and examinations of the first section of the restoration this year have revealed the true extent of the damage (see ‘Image gallery’ and the description of the damage given in ‘The staircase’).

The detailed cavity map that has provided the basis for the necessary reinforcements of the loose layers of plaster resembles a patchwork rug. Following extensive testing and studies of injection patterns in test panels, which were mostly completed and analysed in October, the first two reinforcements of the plaster, in the area of the north-west and south-west hip, are to commence at the beginning of November.

Protecting and reinforcing the particles of the flaking or powdering paint layer in areas of severe salt contamination and plastering is a complex task. Tests and appropriate preliminary experiments are currently being carried out on sample panels (dummies) and postage stamp–sized areas of the fresco. Appropriate reinforcement materials can only be used extensively on the Tiepolo fresco once these tests have been evaluated.

In addition to these ‘substantial’ steps, cleaning work is also currently being carried out, particularly in the main cornice and in the corner sculptures (dust removal).

5. What will the fresco look like after the restoration?

It is not the object of this restoration to restore the great Tiepolo fresco to its ‘former splendour’. Nor would this be possible, since over the centuries countless irreversible changes in the paint layer and the plaster support have taken place. There are a variety of causes for these changes, ranging from the particularly severe damage and losses due to the Second World War to restoration activities dating back as far as the 19th century (see ‘History’).
There will be ‘visual improvements’ in areas in which salt veiling, salt crusts, and salt efflorescence have previously lain on the surface. In addition, so far as is possible, discolouring and stains caused by the growth of mould and damp penetrating the vaulting will be removed. Finally, a careful complete cleaning of the fresco is planned, which will be restricted to dust removal.