Does Ivy damage walls?

ivy on a wall

Is there a wall behind this? (photo by lode CC-BY)

This has been a subject of debate for many years and has particularly exercised the minds of those involved in the heritage industry who protect, conserve and restore our architectural heritage.

Ivy may add character to walls, but it is commonly thought that it will damage walls where the existing mortar is already weakened or loose. It is reported that this will either allow water to seep in-between the joints, or stop moisture, making the wall dry and crumbly. Removal of the ivy will additionally cause further damage.

In an attempt to establish the true position, English Heritage commissioned research by a team from Oxford University’s Rock Breakdown Laboratory. This laboratory researches weathering and rock breakdown in natural environments. The project lasted three years. The team examined common ivy growing on walls in five different locations in England, each providing a different climate and situation.

The result of the research has just been announced. Their conclusion was that there was some evidence that ivy played a protective role shielding the wall from extremes of temperature and moisture which can cause cracks in the stone and damage to the mortar. The ivy was found to act as a ‘thermal barrier’. They also discovered less pollution and salts where the wall was covered by ivy. These pollutants and salts can lead to stone decay.

They did, however, confirm that where walls are already damaged, ivy would find its way into the cracks and holes and damage the structure further.

So it seems that providing the mortar and stone work is in good condition, the ivy can remain. Do note however, that this research was on perimeter walls, not house walls.

The research will allow English Heritage, and even the ordinary householder, to reconsider whether the ivy on their walls should be removed or left in place.

Oxford University School of Geography and the Environment: Ivy on walls – biodeterioration or bioprotection?

English Heritage news

Related questions:

  • Where can I sleep in a castle or a lighthouse?Where can I sleep in a castle or a lighthouse? Have you ever wanted to sleep in a castle, or perhaps a tower, or a folly? Or what about a grand mansion, a tower, or a lighthouse? Or a simple cottage far from the madding crowd? […]
  • Can you touch the stones at Stonehenge?Can you touch the stones at Stonehenge? Nine hundred thousand people visit the Stonehenge monoliths each year, but the experience is tightly controlled by English Heritage. If you visit Stonehenge as a tourist you'll find […]
  • Where are the world’s most endangered monuments?Where are the world’s most endangered monuments? The World Monuments Fund has issued its list of the most threatened world monuments for 2010. The WMF calls attention to "cultural heritage around the world that is threatened by […]
  • Is “Earth Hour” meaningful, or just a stupid gimmick?Is “Earth Hour” meaningful, or just a stupid gimmick? Earth Hour is a campaign to get everyone to switch off their lights for one hour. The 2009 Earth Hour runs from 8.30 to 9.30pm in everyone's local timezone, on Saturday 28 March. But […]
  • Are there any good beaches in the UK?Are there any good beaches in the UK? After a news report about UK beaches whose water quality failed to meet regulatory standards, I heard someone say that they didn't know there were any good beaches in the United […]

  Need research? Quezi's researchers can answer your questions at

Written by | 5,397 views | Tags: , , , ,

No Comments

Comments are closed.

RSS feed for comments on this post.

Privacy Policy | Acknowledgements