Retaining walls, beware!

Retaining walls, beware!

Who is responsible for a retaining wall?

Unless the title deeds make specific reference to responsibility for a wall, it is generally accepted that the person whose land is retained by the wall is responsible for its repair and maintenance, but beware, the situation may be different where the lower land owner has excavated away his own elevated land to provide a lower but level area whilst rightly maintaining support to his neighbour’s higher land.

The devil in the detail

Retaining walls are known to fail during an event such as a heavy storm; and often this is the occasion of failure rather than the cause. Retaining walls are, in principle, covered for damage caused by storm, flood, earthquake, fire, etc. However, when transferring risk to an insurance company consideration must be applied to the proximate (dominant or effective) cause of the wall failure in the event of a loss. If the peril is one of the causes in a chain of events leading naturally and in the ordinary course to the loss or damage to the retaining wall, such loss or damage will be proximately caused by the peril.

Remember, that the onus is on you as the policyholder to prevent losses as far as possible and it is not sufficient for the peril insured against to have facilitated the loss; it must have caused the loss. In other words, any process having gradually taken over time is not covered (this is a universal insurance principle). Failing adequate maintenance, your retaining walls factor of safety may be eroded by gradual loss of strength, change of ground conditions, or blockage of drainage holes, allowing a build-up of water behind the wall adding to the weight of soil. Water can also saturate the softer brickwork and become trapped by the less porous engineering brick/block. This can give rise to failure, either of the entire wall or just to the engineering brick/block as trapped water expands and laterally displaces the engineering brick/block.

Consider the following scenarios:

Scenario: The loading at the top of the wall has increased significantly by the building of a new structure, and this additional load surcharge has overloaded the wall.
Response: This is not landslip, as the wall has failed because of the applied pressure. Further, the damage is likely to be excluded under the accidental damage cover if exclusions above apply.

Scenario: Significant plants, roots and vegetation have damaged the wall structure or jointing causing it to lose structural integrity.
Response: No cover as the collapse is due to gradual deterioration, rather than an insured cause, even though failure may occur on the occasion of an insured event e.g. during a storm.

Scenario: Ground water runoff has flowed into free draining material behind the wall and the lack of working weep holes has resulted in a build-up of water pressure behind the wall structure causing its collapse.
Response: This is not damage caused by landslip, it is unlikely to be storm or flood damage and even if operation of the peril is agreed considerations should be given to general and peril exclusions. It is unlikely to be covered under the accidental damage optional extension.

Scenario: The ground level at the base of the wall has been reduced significantly destabilizing the wall by undermining it and causing it to either slip or collapse forward.
Response: What has reduced the ground level? If this has caused landslip it would fall as landslip, but excluded if the building is not damaged.

What’s excluded?

Whilst some insurance policies may provide ‘accidental damage’ cover, it is important to be aware that this cover generally excludes loss or damage that occurs as a result of gradual deterioration over time, exclusions typically include:

• Faulty workmanship, defective design, the use of defective materials or damage caused by any of these
• Movement, settlement or shrinkage in any part of the buildings or damage caused by any of them
• Damage caused by the movement of the land belonging to the buildings
• Demolition of or structural alteration or structural repair to your home or damage caused by any of them. 

The takeout:

• Beware of retaining walls, not all policies include cover for retaining walls and if they do take note of the perils for which they cover
• Do not rely on “accidental damage cover” to cover you.
• Maintain your retaining walls (a tough task) or take careful consideration in the design thereof.