Please Help: regarding-applicablity-of-service-tax-on-dismantling-service

Dear Freinds,

My Client is a Contractors who undertakes works as contractor or Sub contractor for Dismantling of Building & Commercial Constructions & complete such tasks by hiring labour it own. my query is whether he would be liable for service tax payment if he crossess the exemption limit under Service tax for small service provider...... & if taxable than under which head.........
please reply as soon as possible
thanks in advance

CA ANOOP RANTA