The Central Bank of Nigeria through a circular signed on 13 November 2009 has banned with immediate effect the importation of aluminium roofing sheets less than 0.50mm in thickness and cold roll steel of less than 0.20mm thickness.
 
'In order to ensure that Nigerian consumers get value for money, only aluminium roofing sheets with Nigerian specification (NIS488.2004) of 0.5mm thickness and cold roll steel with 0.20mm thickness are allowed.'
 
All authorised dealers, destination inspection providers and the Nigeria Customs Service. Sanctions for failure to comply include seizing of the items. Transactions initiated before the circular came into force must be fully consummated on or before 12 February 2010.