Works contract input tax credit

Sir, 

My client provides only construction services  for individuals for the construction of residential houses with  labour+material for unregistered persons which comes under 'Works contract, if i am not mistaken.'  The service code is 995411.  My question is whether he can claim input tax credit on cement, steel and other raw materials?  In the competitive market nobody  pays him GST.  Does he have to pay output tax @ 18% if input tax credit is not given out of his profit while filing 3B?  I have studied that ITC is not allowed for 'WORKS CONTRACTS'  I request you to please give me a detailed advise mentioning provisions