uncountable nouns

[jonnapore]

The word "works" is uncountable noun, so when I construct a sentence, do I say "The works is not extensive" or "The works are not extensive"?

 

[Niall]

Here, we have to say The works are not extensive.

"Works" is always plural in the context of engineering works,for example in the sentences:
The works on the M4 are dreadful.
He came home tired from the steelworks every night.