i work in property and although i cant tell you anything about the job, what i can say that the UK is building more houses than ever = the need for more concrete = losts of work for people who need to deliver concrete.
With the increase of eastern block workers willing to work for less it also means that even average companies are doing ok.
if its an established company which looks as if it will stay the course, go for it.
Ask them, they will appreciate it as a constructive question in an interview. Ask them what there 5or10 yer plan is for the company and ask how much they have expanded in last 5/10 years and good luck