The contractor is not responsible for foundation movements caused by activities that were not evident at the time of entering into the contract or as a variation to that contract, or that are undertaken by the owner. These include paving, landscaping, planting trees and drainage works after the site is handed over to the owner.The contractor is not responsible for foundation movements caused by the owner’s failure to maintain drainage systems after the site is handed over to the owner.
In order for domestic footing designs to be practical and economical to construct, AS 2870 – Residential Slabs and Footings accepts that although usually no damage occurs during the life of the building some slight or minor damage to walls and floors due to footing movement is possible. This slight or minor damage is not a defect. Slabs and footings are defective if they fail because they are not designed and constructed in accordance with the BCA and/or AS 2870 – Residential Slabs and Footings.
Slab and footing failures are defects when they are caused by foundation movements that are the result of localised drying and wetting caused by such factors as the effects of trees, excessive wetting or lack of site drainage when these factors were present during construction. Slab and footing failures are also defects where they are caused by foundation movement that is the result of inadequate fill, or inadequate compaction of either fill or natural material irrespective of whether or not the fill may have been provided with a Level 1 Compaction Certificate.
A building set out is defective where the set out has failed to comply with the requirements of the approved drawings, the allotment Certificate of Title, planning or development approval, relevant planning overlays and schemes and building regulations.
Within the first 12 months from completion of the work and provided the building set out has complied with these regulated provisions, the set out for a building is defective if the building is more than 50mm from its correct position and such deviation adversely affects the safe use or reasonable amenity of the building.
Slab and footing failures are also defects where they are caused by foundation movement that is the result of inadequate
fill, or inadequate compaction of either fill or natural material irrespective of whether or not the fill may have been provided with a Level 1 Compaction Certificate.
Surface water is required to be directed away from the building and shaped to prevent ponding of water near or against the footings. Part 3.1.3.3 of the BCA provides minimum surface water drainage requirements.
Finished Floor Levels (FFL) or Reduced Levels (RL) are defective where they do not comply with planning and building requirements, for example minimum levels in flood prone areas. Within the first 12 months from completion of the work, Finished Floor Levels (FFL) or Reduced Levels (RL) are defective where:
• they depart from the documented FFL or RL by more than 40mm and such deviation adversely affects the safe use or reasonable amenity of the building; or
• floors that are documented to be on the same plane are constructed on different planes and such deviation adversely affects the safe use or reasonable amenity of the building; or
• the building work is an extension or addition and new floor levels do not match the existing building floor levels and such deviation adversely affects the safe use or reasonable amenity of the building.
Except where documented otherwise, new floors are defective if within 12 months from completion of the work, they differ in level by more than 10mm in any room or area, or more than 12mm in any 3m length and such deviation adversely affects the safe use or reasonable amenity of the building. The overall deviation of floor level to entire building footprint shall not exceed 20mm within 12 months from date of completion of the work and such deviation adversely affects the safe use or reasonable amenity of the building.
Repairs, where failure has been due to cracking and/or movement, may involve the removal of the affected area. Within the first 12 months
of completion of the repair work, the repair is defective if it does not, as closely as practicable, match the existing work in appearance, colour and texture. Minor variations in finish are not considered defective. Where repairs are made to a domestic slab designed in accordance with the BCA to act as part of a termite management system, any repairs are defective, unless they ensure on completion that the termite management system is appropriately re-instated in accordance with the requirements of the BCA.
The performance requirements of the BCA require, amongst other things, that buildings safeguard occupants from illness and injury and protect buildings from damage caused by surface water, external moisture entering a building and the accumulation of internal moisture in a building. Accordingly, the waterproofing of slab and footing systems is defective if it permits surface water, sub-surface water and other external moisture to enter a building to the extent that it compromises the health and safety of occupants or has the potential to damage the building or its contents. (e.g. permits mould growth or damages floor finishes, carpets etc.).
The work is not defective if such water penetration is caused by actions or inactions by the owner, or others outside of the contractor’s control including such things as landscaping
that directs water towards the building or restricts the free flow of water away from the building, excessive garden watering adjacent to the building and the subsequent construction of paving adjacent to the building that compromises the ability of the water to drain away from
the building.
