For details on safety requirements of building a playground in your church, there are some websites that may be of help:
kidsafensw.org has a section on Playground Safety which has fact sheets available for free. The Australian Standards that are appropriate for Playgrounds are also listed and there is a link to SAI Global where they can be purchased.

Also on Kidsafensw website, are side tabs, look for Fact Sheets; this includes surfacing and fall zone details. The Kidsafe NSW Playground Advisory Unit can be contacted on 02 9845 0890.

Also if you need more detailed info, you can join PlayAustralia, but there is a cost involved, http://www.playaustralia.org.au/content/membership-payment-methods
If you do join them, it sounds like they can have an advisory service.