Bulk stabilisation of housing stock
A housing association in the Midlands had a large number of properties that had suffered from structural movement due to the drying of soils and drainage systems being in a state of disrepair. The properties were largely Victorian terraced homes located on busy one-way streets.
The traditional solution, mass concrete underpinning, requires properties to be empty as major excavation is needed in and around the structure. Therefore Geobear was approached to provide an alternative solution to tackle dozens of properties in as short a timeframe as possible.
Drilling through the foundations with limited access
The managing agent was introduced to Geobear, a ground engineering company that uses innovative methods to stabilise properties. The method used by Geobear injects an expansive geopolymer resin into the ground beneath foundations. The resin solidifies in the ground and compacts granular soils, or fills the fissures in clay soils, providing full stabilisation beneath the sinking foundation and preventing any further structural movement.
By working in partnership, dozens of properties were stabilised in a single month, providing cost savings to the client and importantly, with no requirement for tenants to move out of the property or neighbourhoods disrupted.
In choosing the Geobear solution, the Housing Association was able to process the foundation maintenance requirements for properties in bulk. Dealing with groups of properties in this manner greatly reduced the administrative time required and enabled all the works to be processed and scheduled within weeks, rather than over a course of a number of years.
With this method of stabilisation, the client did not have to process the temporary relocation of tenants or utilise void properties. For each individual property, this would save thousands in relocation costs and potentially lost rental income, notwithstanding the inconvenience for the tenants.
For the tenants of the properties, their primary concerns were not having to move out of their home, but also the safety of the property they lived in. Living within a property that has cracks in the walls caused by subsidence can be a major concern. With the maintenance works completed they have the assurance that the property is being maintained and safe to live in.
Alternatives
Drain monitoring to ensure drains are not affected
The traditional alternative to stabilise buildings suffering with subsidence is mass concrete underpinning. This is a labour-intensive activity that takes many weeks or even months to complete. It involves major excavation around the foundations of properties and damages surrounding areas. The location of the property is an important factor as underpinning the front elevation of a row of pavement lined, terraced properties, located on busy one-way streets is a major undertaking and impacts the wider community.
However, with the Geobear solution only one van was required to park outside the properties. Consequently, there was virtually no disruption to any other residents in the community, especially as on average it took 2 days to stabilise each property
The cost to underpin a single property is in a similar bracket to the Geobear solution, but with measurable financial benefits come in the form of reduced administrative costs and more significantly their being no relocation costs, or lost rental income . The relocation for a family whilst traditional underpinning is completed could amount to in excess of £5k, in using Geobear this cost is removed.
The future
Drone view of site in Midlands
Subsidence is an issue facing all associations, some more than others. At present procurement of underpinning services differs depending whether it’s Council or Association managed.
If the example provided by Geobear can be adopted by other housing associations, the cost benefits are significant. For example, if an association has 10 properties with subsidence each requiring tenant relocation, there is a potential for £50k in cost savings.
By adopting a partnered approach to property subsidence with Geobear, the sector as a whole could save millions in costs and ensure it’s housing stock is fit for purpose, and minimise the quantity of stock unavailable to tenants.
To discuss working with Geobear, please contact Chris Carlton: [email protected] 0800 084 3503.
