Two men in a white Ford Transit van with a beacon light on the roof drove into the yard at the firm on Bridge Street just after 5.30pm on Monday, April 18.
Police said a steamroller was then driven into the back of the van before it was driven away.
It is one of a number of similar offences in Goole and the wider East Riding area currently being investigated.
Both suspects are described as white men aged between 20 and 30. One had short brown hair. At one point during the theft he wore a dark deer stalker-style hat and a high visibility jacket.
The second suspect had dark brown hair, cut in a Mohican style. He wore black trousers, a white T-shirt and a dark zip-up top.
Anyone with information is asked to call police on 101, quoting crime reference number 2182255.