Welcome to the Roman Baths Blog!

This blog is a behind the scenes look at the Roman Baths in Bath. We hope you enjoy reading our stories about life surrounding the Roman Baths.

Wednesday, 2 March 2011

A Monument in the Mist.

The number one question I get asked as I am walking around the site is, “what is the liquid you are spraying over the stones?”

Humidification system in action - Temple Precinct
Answer = The liquid is plain old tap water and it’s not being sprayed over the stones but into the atmosphere.

Next question = Why?

Answer = To prevent salt crystal growth which can cause stones to break where cracks exist and ceramic building material to breakdown.

Salt crystal growth - Temple Precinct
Next question = What is salt crystal growth?

Answer = Salts are contained within the stone and they expand as stone dries out, causing the weaker surrounding material to be pushed out. In a fluctuating environment the processes of dilution/absorption and concentration/expansion causes the stone to crack and clay to break down. Salt damage results largely from the growth of salt crystals within a porous structure. A broad variety of damage features—from granular disintegration to flaking and scaling. The water spray is keeping the environment stable i.e. constantly damp and aims to stop this process from happening.

Question = Why not just remove the salts?

Answer = Unfortunately due to the nature of the site, salts are constantly going to be present. The salts are present in the underlying soil fed by the natural spring water which is very rich in metals, salts and minerals and are drawn up by the stone and ceramic building material.

Pillars made from ceramic bricks - West Baths
Most people walk away very happy after this discussion= job done!

Can you think of any more monument conservation questions you might like to ask?

For a good place to start if you would like learn more about salt crystal growth follow the link below

Helen Harman - Collection Assistant

1 comment:

  1. I was asked very similar questions (by the guides) when applying lime-poultice to the stones down in the Temple Precinct, just after it was opened to the public, Helen. They thought I was taking a plaster mould...