Substrate definitions

The term 'substrate' refers to any solid substance to which another substance is applied so that the second substance adheres to the substrate.

As a variation of ‘substratum’, the term can refer to a layer of residual bedrock, sediments or deposits that are found beneath the topsoil. For the construction of foundations, the substrate type (e.g. soil, rock, clay, and so on) is one of the factors that will determine the type of foundation used.

The term is also used for ‘filler’ products,applied to brick, ceramics, concrete, plaster, and so on.

With regard to sealants, paint and other surface finishes, the substrate is the surface to which they are applied.

Biodiversity in new housing developments: creating wildlife-friendly communities, published by the NHBC Foundation in April 2021 defines a substrate as: ‘A medium on which vegetation grows, including soils, sub-soil, wood and masonry.’

PAS 9980:2022, Fire risk appraisal of external wall construction and cladding of existing blocks of flats – Code of practice, published by BSI Standards Limited in 2022, defines substrate as: ‘a construction onto which other materials or products are attached or applied… In the case of a cladding system, its substrates typically include masonry and lightweight framing systems, such as an SFS (steel framing system).’

[edit] Related articles on Designing Buildings

• Binding agent.
• Finishes.
• How the substrate affects external timber doors.
• Intumescent coatings.
• Paints and coatings.
• Plaster.
• Screed.
• Sealant.
• Structural adhesives.
• Subsoil.
• Substructure.