J LONG AND SON LTD , HAS BEEN RECONISED AS ONE OF NORTHERN IRELANDS LEADING NATURAL SLATE SUPPLIERS AND ROOFING SUPPLIES EXPERTS. J LONG & SON SPECIALISE IN IMPORTING TOP QUALITY ROOFING SLATE FROM LEADING QUARRY MANUFACTURES FROM ALL OVER THE WORLD SUCH AS DC X1 , DELCARMEN SPANISH ,SAINTAIGO SPANISH , BRAZILLIAN GRAPHITE AND GREY GREEN .BASED IN LARNE CO ANTRIM NORTHERN IRELAND J LONG & SON STRIVE TO ONLY INPORT TOP QUALITY SLATE TO MEET BRITISH AND EUROPEAN STANDARDS AND NHBC, UNDER THE GUIDE LINES ALL SLATE SHOULD HAVEACCOMPANYING COMMERCIAL DOCUMENTS TO ENSURE THE PRODUCTS ON OFFER HAVE ACCEPTABLE DURABILITY AND MEET THE MINIMUM REQUIREMENTS , WATER ABSORPTION NO GREATER THAN 0.6% IE A1 CODE ,/ CARBONATE CONTENT S1 CODE HIGH CARBON CAN LEAD TO ACCELERATED EROSION AND COLOUR CHANGE, THERMAL CYCLE THIS IS A TEST FOR REACTIVE METALLIC MINERALS THAT MAY LEAD TO STANING ,PITTING,RUSTING FOR COMPLIANCE T1 CODE .ALSO CAST IRON GUTTERING, AWARD WINNER ROOF BLOCK FACIA .