Home > Part 5 > 5.1 Substructure and ground bearing floors > Appendices

5.1 Substructure and ground bearing floors

5.1 - Appendix 5.1A

    Materials for use as fill

5.1 - Appendix 5.1B

    Basement constructions

5.1 - Appendix 5.1C

    Typical details for basements

Appendix 5.1-A

Materials for use as fill

Hazardous materials	The following materials require testing to ensure their suitability for use as fill to support ground bearing slabs or as backfill to associated trenches: acid wastes reactive materials materials that include sulfates (eg gypsum) organic materials toxic materials materials that cause noxious fumes, rot, undue settlement or damage to surrounding materials.
Test requirements	Tests should be carried out by a suitable qualified person with a detailed knowledge of: the material to be tested, and the proposed conditions of use. The samples tested must be representative of the true nature of the material. It may be necessary to take a number of samples to find out the material characteristics of the fill. Tests for sulfate content should be carried out in accordance with the recommendations of BRE Digest 363 (current edition).
Sources of fill material	Where the material is of a stable and uniform type from one source, it may only be necessary to check its suitability once. If material is variable, or from a number of sources, it should all be suitable. Regular inspections and/or testing may be required. Where industrial waste is permitted as fill material, it is essential that sufficient testing is carried out to ensure suitability. Where material is obtained from stockpiles, check the material is uniform. Different forms of stockpiling can affect particle size/grading. The outside of a stockpile may be weathered and may not be the same as unweathered material.
Fill requiring NHBC approval	The following types of fill should not be used unless written permission has been obtained from NHBC: colliery shale and any other residue from mineral extraction slags furnace ashes and other products of combustion material obtained from demolition on wet sites, or sites with a high water table, crushed or broken bricks which have S1 designation (as defined in BS EN 771).
Expansive materials	Fill containing expansive materials is not acceptable for use as support to ground bearing slabs or as backfill to associated trenches.

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Appendix 5.1-B

Basement constructions

This Appendix shows the three types of basement constructions.


Type A structure - tanked protection (water resistance reliant on waterproofing)	Type A structure - tanked protection (water resistance reliant on waterproofing)

Type B structure - structurally integral protection (water-resistant concrete) (water resistance reliant specifically on the concrete construction but may be combined with additional waterproofing)	Type C structure - drained cavity (water resistance reliant on collecting and disposing of any water within the internal cavity system)

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Appendix 5.1-C

Typical details for basements

This Appendix contains generic details for basements. Because of the variations between different waterproofing systems, they should not be used as construction details. The manufacturer of the tanking system should be consulted.


Type A structure Strip foundation without starter bars	Type B structure Integral protection - water-resisting concrete

Type C structure Strip foundation without starter bars	Type C structure Strip or piled foundation with starter bars

Type A structure Reinforced masonry on concrete raft	Type C structure Drained cavity construction

Type C structure Reinforced masonry on concrete raft	Example of linking waterproofing with DPC/cavity tray

Drainage connection avoiding penetration of the waterproofing system by the soil stack	Drainage connection penetrating basement wall