There is one thing to keep in mind that spiders are an inevitable part of the Australian wildlife, you will definitely encounter them in your life. Having said that there are few things you can do to keep the infestation undercontrol. First clean your garden beds and trim your vegetation. Highly maintained gardens will allow less opportunity for spiders to make their webs and infest your outdoors. Secondly do not stack tiles or wood along the outer wall of your house. These undisturbed areas in your house are best harborage for spiders. Third you need to do some weekly cleanup all around your house, through unwanted things and do not allow stuff to gather which you are not going to use. Cleanup and shuffle things in your garage too, this shuffling will help you to keep the spiders infestation under control. Last but the least , get professional spider spray done for your house. This yearly treatment will keep your house safe from large infestations.