Cut one large strip of mounting board for the deck and glue two thin strip of card to each edge to strengthen it.
Cut a piece of net the same size as the deck.
Glue one end of the netting to the end of the board with PVA and then glue a thin strip of card on top to hold it in place. Clamp with a clothes peg until dry.
Paint the deck all over with watery PVA and then glue the other end of the net as before.
Stick two thin strips of card on top of the deck at the sides to cover up the edge of the netting.
Decorate the edges of the walkway with scraps of card and plastic.
Paint the floor deck black and drybrush with a mixture of silver and white.
Paint the outer edges of the deck a dark colour and then drybrush.
The diagonal striping at the edges was drawn with Photoshop, printed out and then stuck on.