"spans the width" is a correct and usable phrase in written English.
You can use this phrase to describe something that extends over or covers a wide area. For example: "The wings of the golden eagle span the width of the sky."
A thick sandstone-slab waterfall that looms over Jingga spans the width of one end of this 65m pool.
A sense of essential form characterizes the swimmer in "Fast Start" by Emily Trueblood from New York City in which the swimmer's arched back spans the width of the print.
Lake Chad is the principal life source of the Sahel, a semiarid band that spans the width of Africa and separates the Sahara, in the north, from the savanna, in the south.
Its passenger compartment spans the width of two traffic lanes and sits high above the road surface, on a pair of fencelike stilts that leave the road clear for ordinary cars to pass underneath.
Downstairs a small stage spans the width of the room, replete with velvet curtains and disco ball – close the curtains and it transforms into a fitting room where you can try on playful womenswear like blouses with hexagon-shaped puff-sleeves and asymmetrical tulip skirts.
Rubicon Property headed the sale of the five-story property which features five bedrooms, eight fireplaces, and a Juliet balcony that spans the width of the entire building.
Each ceiling bed becomes, in effect, a fixed beam spanning the width of the cave passage.
OUTDOOR SPACE: There are the two decks and the boat dock, which together span the width of the house.
Often the joists are not long enough to span the width of the house, so builders use two joists nailed together at midpoint.
To make her more foolish, Mr. Newman staged that entrance behind tacky rippling fabric, spanning the width of the stage, meant to suggest a hedge.
Steel girders span the width of the house, allowing for a glass facade and an open interior space.
