Description

AS 2870 – Residential slabs and footings

AS 2870 sets out the criteria for the classification of a site and the design and construction of a footing system for a single dwelling house, townhouse or similar structure which may be detached or separated by a party wall or common wall, but not situated vertically above or below another dwelling, including buildings classified as Class 1 and Class 10a in the Building Code of Australia.

AS 2870 may also be used for other forms of construction, including some light industrial, commercial and institutional buildings if they are similar to houses in size, loading and superstructure flexibility. The footing systems for which designs are given include slab on ground, stiffened rafts, waffle rafts, strip footings, pad footings and piled footings.

NOTE: This Standard gives no advice on detailing of the connection of superstructures to the footing systems for wind loads or earthquake loads.

For design purposes, the life of the structure is taken to be 50 years.

NOTES:

AS 2870 has been widely used for a number of years for the economical design of footings and slabs. Economical designs that avoid significant damage are practicable only if the soil moisture content of the foundation material under the footing or slab is stable or within reasonable limits of stability over the design life of the house or structure. For all sites (in particular sites with reactive soils) drainage and soil moisture conditions around the building need to be managed to avoid abnormal moisture conditions, as outlined in Clause 1.3.3, which may result in building damage.

Site management recommendations are given in Appendix B.

Where slab on ground construction is used for long slabs and large houses, particular consideration in design may be needed to avoid significant damage.

Information on earthquake actions is included in AS 1170 Part 4. Information on wind actions is included in AS 1170 Part 2 and AS 4055.