Our task.

Installation of root barrier in rear garden William Hunt Consulting were asked to table a solution to a long-standing subsidence claim where there were numerous protected oaks to the rear of the house, all located on adjacent land owned by the Local Authority. The rear of the house was suffering from very severe damage and mitigation had been unsuccessful. Access to the back garden could only be gained from a narrow alleyway.

Conventional solution.

Install duration – 8 weeks
Cost – £95,000

Our innovative solution.

Install duration – 2 weeks (75% saving)
Cost – £16,000 (83% saving)

The conventional approach.

In circumstances where mitigation has been unsuccessful and there is insufficient space to install a conventional root barrier, engineers are often forced to resort to expensive and highly disruptive substructure stabilisation schemes, such as piling. The timeframes and costs involved in these types of projects are often significant and rarely provide the customer with a positive experience.

What we did.

With the alleyway less than 900mm wide, access into the rear garden was seen as a limiting factor in any scheme proposed. With our specially designed rig however, we were able to enter the rear garden and install a Compact Barrier to a depth of 4.0m across the width of the site. This barrier was installed in under two weeks at a fraction of the cost of a sub-structure scheme and with negligible disruption to the customer.


  1. Cost saving – circa. £79,000 when compared with a piled underpinning scheme
  2. Time saving on site – circa. 6 weeks
  3. Disruption – No internal access required, works carried out in the garden only
  4. Quality of product – With a material guarantee of 60 years the Compact Barrier provides  a lasting solution.
  5. Customer satisfaction – with minimal disruption and confidence that the subsidence  had been addressed