The STOPDIGGING! Ground Screw Foundation System is the ideal foundation system that combines the best of building code performance with ease of installation with sustainability.

It is a direct alternative to the traditional timber pile system. Wherever a timber pile could be used, a STOPDIGGING! ground screw will also work. Its performance as well as acceptance by council is assured through CodeMark.

In most situations the foundation system can be designed without the involvement of a structural engineer and in these situations CodeMark removes the risk for the designer.

From a sustainability perspective there are few other foundation systems that are quite as sustainable.

It can be used for longer than an equivalent timber pile. The thickness of the zinc layer is such that it will still be protecting the steel substrate after 100 years. And when the zinc layer does become thinner it can simply be re-glavanized.

It can be installed without the need to remove layers of dirt from site. This reduces the time taken to fully install the system days as opposed to weeks when taking into account clearing of the site. It creates less construction waste. It involves less transport related emissions - no endless line of trucks removing soil from site.

It sets the floor of the house above ground level, providing additional resilience against the threat of ground water flooring.

The process is very simple.

The CodeMark is the consenting tool for all STOPDIGGING! Ground screw foundation design. Nothing is out of scope.

STOPDIGGING! Ground screws are a direct alternative for timber piles.

Scenario A

Where the ground screws are going to be used for a building where

- the floor load is </= 3kPa

- the head of the ground screw is <900 mm above ground, or

- there is no requirement for lateral bracing between ground screws

- the joist and bearer spacings are within the range provided for in the tables for Appendix 2 of the STOPDIGGING design guide.

A structural engineer is not required.

The process is:

1. Establish that the type of soil is one of those that are listed as acceptable in Appendix 1.

2. Design the subfloor using NZS3604 or the Nash Standard. T

3. Position the ground screws is exactly the same as if you were placing timber piles.

4. Go to Appendix 2 and for the floor load/building specifics and joist/bearer spacing you read off the design and test loads that are required. Record these on the applicable plan sheet.

5. Record the founding depth. In some cases (well most cases) the council will have required a geotechnical report. The report should provide detail as to the depth at which the foundations should be founded. This depth is the depth at which testing of the grounds screws will occur. So it is important to note next to the design and test loads, the founding depth.

6. Include the fixing details on the plans - they are also in the design guide

7. Having followed this process then as the designer you complete the design declaration which is a condition of the CodeMark and is you saying that you have followed the design guide.

Scenario B

If any of the above does not apply then a structural engineer will be required to specify the design and test loads, and placement of the ground screws.

Where condition 1(a) of the CodeMark certificate does not apply then an engineer is required to provide the ground screw spacing and the associated design and test loads. A PS1 is not required but the engineer signs the Design Declaration. For the installation of the ground screws in this situation a PS4 is not required. The installer is required to provide an installation declaration.

While the answer should be no, we do know that councils are typically demanding one.

However this does not necessarily mean that a structural engineer will be required.

The designer can simply consider the depth to which the foundation system needs to be founded and then proceed as normal.

The design guide, design declaration and installation guides should only be sent to the designer or at a push a building company. do not send this information to a building owner as it is likely to confuse them. The building owner should only b e sent marketing material