Ivy (Hedera helix) is an evergreen climbing plant which is often grown as a decorative cover on house walls and fences. The plant has glossy leaves with three or five pointed lobes, often strongly veined, and grows in any type of soil, tolerating both deep shade and full sun.
Why does Ivy create problems for Home Surveys?
Ivy will grow into a dense mat, with thick woody stems growing in all directions. This dense cover can hide defects in a building, hindering maintenance and making it difficult for a proper survey to be carried out.
The plant supports itself by aerial roots which cling to the masonry of a building. These roots can penetrate cracks or joints, especially in older brick or stonework with lime mortar joints, which can cause structural damage. It can also cause damage if allowed to grow over walls which have been surfaced with stucco, pebble-dash, or other rendering, and it may cause the finish to detach from the wall.
Ivy can grow to a considerable height, so will require regular trimming to ensure that it does not grow into gutters. Shoots and runners must also be prevented from growing into roof spaces and voids or beneath foundations where they will cause damage.
Does Ivy cause dampness?
It has generally been thought that walls covered with ivy will be more prone to damp problems. However, a recent study carried out for English Nature indicated that the ivy can in fact help to weatherproof a wall, as well as providing protection from the effects of pollution.
Ivy can be difficult to remove. As its roots cling to the building pulling it away can cause more damage and will often leave root-tips embedded in mortar or plaster which is unsightly and difficult to remove. The leaves are resistant to weed killers, and any roots remaining in the ground will quickly grow again. Therefore removing any substantial growth of ivy will probably require expensive professional work.
English Heritage now advises against indiscriminate removal, but if ivy is left it will need regular management.
A building survey will indicate if there are any apparent problems from the growth of ivy, and may recommend a further survey or inspection by a specialist.