Why is my background image on the home page not the full width?

Hi there,

You have this CSS on your site:

.home div#page {
    max-width:100%; 
    background-image: url('https://www.nrhsn.org.au/wordpress/wp-content/uploads/nrhsn-front-bg5.jpg'); ; background-repeat: no-repeat;
    background-attachment: scroll;
    background-position: center;
}

Add this CSS in it:

background-size: cover;

Let us know if if fits what you were aiming for. :D