Polish immigrants and others are without doubt dragging pay rates down and building companies are obviously using the "hard workers" statement as an excuse to pay less
Wrong. From what I have seen - this is how it works:
The Employee knows that wages are lower in Poland. He offers the Pole £50 when normally it's £100, but in Poland he'd get £25. The Pole says yes because he's making double and he can't risk losing the job to the next Pole. The employee makes £50.
However - once the Poles settle down they learn how to deal with the employees and gradually get better pay.
I could never afford builders at the going UK rate anyhow - and I'm on £30K. I have a roof over my head because a pole agreed to fix my house for a price I could afford.
Allowing all these Poles in to the U.K will no doubt bring general wage levels down and quality of building work will suffer too. A lot of these Poles pretend they know everything and can turn their hands to anything, rather like a lot on this forum! However, in general, their work can even be dangerous! The future working class in this country is going to have serious problems.
So when the building inspector arrives on site - and issues pass certificates etc...that means nothing or are they cowboys also?
"rather like a lot on this forum! "
don't be so hard on yourself