Incinerator Bottom Ash 

As the UK moves away from landfill, we now manage household waste using energy from waste facilities. The residue from this process is incinerator bottom ash, which is a heterogeneous material that contains concrete, ceramics, glass, brick, clinker, some metals and fused material particles. 

Under contract to the EFW facilities, Day Group Ltd is experienced in the removal of IBA, as well as in the recycling and marketing of incinerator bottom ash aggregate (IBAA).


Incinerator bottom ash aggregate (IBAA) is the result of putting IBA through one of our three processing sites that removes much of the metal content and prepares the aggregate sizes. It has been an accepted and widely used sustainable aggregate both in the UK and on the continent for many years. Over five million tonnes have been used as sub-base and capping material in numerous applications over that 10-year period. 

It is a sustainable and cost-effective option that complies with European and British Standards as well as sections of the Specification for Highway Works. 


Our IBAA is a manufactured aggregate compliant with various material designations from the Specification for Highway Works 600 and 800 series. It may also be used as a constituent of a granular material compliant to the same SHW 600 and 800 series. Manufactured aggregates must comply with the same requirements as primary materials. Given this, users and specifiers can choose a sustainable option such as IBAA, with the confidence that it will be fit for purpose and perform comparably with a primary material. 

Aggregate Mixtures 

Our IBAA may be used as a constituent in various aggregate mixtures. Mixtures can contain up to 50% IBAA as a constituent, this improves the grading of the overall mixture and aids with material compaction. All mixtures are regularly tested to demonstrate they are compliant with the relevant specification. 


Unprocessed IBA is brought into our purpose-built plants at Brentford, Greenwich and Avonmouth using HGV tipper vehicles or by rail. The material is assessed on arrival against our site-specific acceptance criteria and then stockpiled until it has suitably aged. Once this has occurred it will be ready for processing. 

The process involves screening the material, separating the ferrous and non-ferrous metals for external recycling, re-screening, then further metal removal and then final product stockpiling. Dependent on the processing plant this results in two or three sizes of material being sent for stockpiling. These varying sized products are then blended together to produce an IBAA compliant to specifications. 

Contact Us

For more information please contact our Recycling department 

020 8380 9600