Bulk filling materials
The term ‘fill’ refers to material used to artificially raise existing ground levels. Bulk filling materials typically include soil, rocks and aggregates and coal ash.
Soil is used for example, for the formation of embankments and other areas of landscape that require fill. It is common to 'cut' soil from the high points of a site and place it in layers in lower areas, in a process known as 'cut and fill'. For more information see Cut and fill.
The soil used for bulk filling must be suitable to remain stable in the long-term. Examples of unsuitable soil material for filling includes:
- Soil from swamps, bogs and marshes.
- Perishable material such as peat, logs and stumps.
- Frozen materials.
- Materials having a liquid limit exceeding 80 and/or a plasticity index exceeding 50.
See also: Types of soil.
Rock fill consists of hard material of a suitable size for compaction and may include crushed stone, hard brick, concrete or other hard inert material. For more information, see Aggregate.
Coal ash is a material obtained from coal-fired power stations. For more information, see Coal ash.
Cellular Concrete (Foamed Concrete) has the advantages that it does not require compaction, does settle over time and it can be re-excavated at a later date if necessary. Large amounts can be placed quickly through small openings, so it is often used for emergency void filling, for example, following the appearance of sink holes or an underground tunnel collapse.
[edit] Related articles on Designing Buildings
Featured articles and news
Boiler Upgrade Scheme and certifications consultation
Summary of government consultation which closes 11 June 2025.
Deputy editor of AT, Tim Fraser, discusses the newly formed society with its current chair, Chris Halligan MCIAT.
Barratt Lo-E passivhaus standard homes planned enmasse
With an initial 728 Lo-E homes across two sites and many more planned for the future.
Government urged to uphold Warm Homes commitment
ECA and industry bodies write to Government concerning its 13.2 billion Warm Homes manifesto commitment.
Places of Worship in Britain and Ireland, 1929-1990. Book review.
The emancipation of women in art.
CIOB Construction Manager of the Year 2025
Just one of the winners at the CIOB Awards 2025.
Call for independent National Grenfell oversight mechanism
MHCLG share findings of Building Safety Inquiry in letter to Secretary of State and Minister for Building Safety.
The Architectural Technology Awards
AT Awards now open for this the sixth decade of CIAT.
50th Golden anniversary ECA Edmundson awards
Deadline for submissions Friday 30 May 2025.
The benefits of precast, off-site foundation systems
Top ten benefits of this notable innovation.
Encouraging individuals to take action saving water at home, work, and in their communities.
Takes a community to support mental health and wellbeing
The why of becoming a Mental Health Instructor explained.
Mental health awareness week 13-18 May
The theme is communities, they can provide a sense of belonging, safety, support in hard times, and a sense purpose.
Mental health support on the rise but workers still struggling
CIOB Understanding Mental Health in the Built Environment 2025 shows.
Design and construction material libraries
Material, sample, product or detail libraries a key component of any architectural design practice.
Construction Products Reform Green Paper and Consultation
Still time to respond as consultation closes on 21 May 2025.
Resilient façade systems for smog reduction in Shanghai
A technical approach using computer simulation and analysis of solar radiation, wind patterns, and ventilation.