Monitoring the Great Stairs environment

The Great Jacobean Staircase at Knole, Sevenoaks, Kent

The Great Staircase was entirely remodeled by Thomas, 1st Earl of Dorset, between 1605 and 1608. It formed a key stage in the formal procession of the family and their guests from the Great Hall to the state rooms on the first floor.
The Great Staircase at Knole was remodelled by Thomas, 1st Earl of Dorset between 1605-1608 at Knole, Sevenoaks, Kent

The wall paintings decorating the main staircase at Knole are rare and very important survivals of Renaissance decoration. Dating from about 1603, they are one of only two complete schemes which survive from this period (the other is at Harrington Hall in Worcestershire) and presage the development of sumptuous painted staircase schemes in the late 17th or early eighteenth century, as seen in the King’s Apartment at Hampton Court Palace.
The Great Staircase from the landing at Knole, Sevenoaks, Kent

The paintings were executed in oil on plaster and have been unstable from an early period. Oil paint tends to lift and flake in the English climate, and their location also makes them particularly vulnerable to damage by touching. Flaking eventually leads to loss of the paint, seen in the white spots over the painted balustrade. The following images illustrate some of the damage and earlier remedial conservation repairs that have taken place over the years:

Areas of paint flaking revealing the plaster underneath

Areas of paint flaking revealing the plaster underneath

Cracking in the paint surface

Patches of previous repair, some of which are now failing and the paint is flaking off again

Patches of earlier repair, some of which are now failing and the paint is flaking off again.

As a part of our Inspired by Knole conservation project we are currently undertaking some extensive environmental monitoring of the staircase, internally and externally. We have placed temperature and relative humidity sensors on the external wall of the staircase and on the inside wall.

The external sensor, on the east facing wall

One of the internal sensors, on the north wall. The second is positioned on the east wall

One of the internal sensors, on the north wall. The second is positioned on the east wall

This will allow us to monitor what the temperature and relative humidity levels of the external wall surface and the internal wall paintings. Using time lapse photography we are also recording where direct sunlight falls on the external and internal walls.

The time lapse camera recording direct sunlight on the external wall of the Great Stairs.

The time lapse camera recording direct sunlight on the external wall of the Great Stairs.

 Our conservators who came to install the monitoring equipment also took some thermal images of the walls, another method to record the temperature of the wall surfaces.

Inside thermal imaging shot

Inside thermal imaging shot.

 

We are also monitoring another two wall surfaces to draw comparisons with the Great Stairs. The Spangled Bedroom, with new render and insulation; and the Brown Gallery which has relatively new render but no wall insulation. In these locations we have a temperature and relative humidity on the external surface and in-between the render and internal plaster. By monitoring the effects of new render and a wall with and without insulation, this will help us decide what the best method of protection will be for the Great Stairs wall paintings.

Alex, Emily, Lucy, Melinda, Sarah and Zena

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s