Ivy on Walls

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Ivy on Walls
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Ivy on Walls

• Since the early C19th ivy has almost always been
  considered damaging to walls and removed without
  thought
• Sir Lionel Earle, Secretary of the Office of
  Works wrote in 1923
• I also think that all the ivy on the walls
  should be cut.

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Ivy on Walls

• Since the early C19th ivy has almost always been
  considered damaging to walls and removed without
  thought
• Sir Lionel Earle, Secretary of the Office of
  Works wrote in 1923
• I also think that all the ivy on the walls
  should be cut. I believe the Queen favours such
  a policy.

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Ivy on Walls

• Since the early C19th ivy has almost always been
  considered damaging to walls and removed without
  thought
• Sir Lionel Earle, Secretary of the Office of
  Works wrote in 1923
• I also think that all the ivy on the walls
  should be cut. I believe the Queen favours such
  a policy. Ivy is a rank and odious plant

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Ivy on Walls

• This research project aims to
• test whether ivy can be protective
• Investigate what damaging effects ivy may have
• make recommendations for the management of ivy on
  walls

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Ivy on Walls
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Ivy on Walls
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Can ivy be protective ?

• The two principal causes of erosion on exposed
  wall faces are
• The freeze / thaw cycle
• The wet / dry cycle
• A covering of ivy may create a micro-climate at
  the wallface which moderates the upper and lower
  limits of these cycles creating a more stable
  environment

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Can ivy be protective ?

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Can ivy be protective ?

• In some locations air borne pollutants can prove
  harmful to stonework and a covering of evergreen
  vegetation can reduce this problem

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Is ivy damaging ?

• There are a number of strongly held beliefs
  about the damaging effect of ivy
• It roots into walls
• It sucks water out of walls
• It makes walls damp
• It exudes acid which eats into walls
• It pulls walls down

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Is ivy damaging ?

• It roots into walls
• In some instances it does causing serious
  damage
• but frequently it does not
• we are looking at what causes it to root into a
  wall

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Is ivy damaging ?

• It sucks water out of walls
• There is no evidence to show that the aerial
  roots have any water absorption capacity
• but equally none to prove they dont !
• We are investigating this issue

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Is ivy damaging ?

• It makes walls damp
• We believe this is unlikely, but the relative
  humidity data from the test walls should clarify
  this

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Is ivy damaging ?

• It exudes acid which eats into walls
• the mechanism by which the aerial roots cling to
  surfaces is poorly understood, but may initially
  involve acid secretion.
• We are investigating this issue

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Is ivy damaging ?

• It pulls walls down
• Ivy has no power to do this, however there can
  be a problem caused by increasing wind resistance
• An all year round evergreen sail especially
  the flowering stems - can make unstable masonry
  susceptible to wind damage
• We are looking at the potential of this effect

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Project outcome

• The ultimate aim of this project is to provide
  practical advice on
• Whether ivy can provide beneficial protection to
  monuments
• In what circumstances ivy can be damaging
• What is the best way to manage ivy on monuments

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Interim management advice

• There are a number of unanswered questions about
  ivy and until they are answered
• Dont automatically remove ivy from a monument
• Take a close look to see it is actually causing
  any damage
• Ensure that its removal will be beneficial and is
  not going to create worse problems in the long
  term