Holding back security deposit and cost of roof repair

[Sudhir N.]

A tenant of my property in Philadelphia recently vacated the unit after a two year stay. He had exclusive access to the rooftop of the building and in fact the rooftop could be accessed only from the unit. The post exit inspection revealed several damages to the roof. It appears the tenant had installed some sort of a wooden deck or fixture and there is outline on the roof as proof. There are several drilled holes and a badly done job of patching them up. There was a storm a week or so after the tenant left and the roof started leaking specifically through the damaged areas. I got couple of contractors to come take a look at the problem. One said all of the leaking was only due to the drilled holes and resulting damages. The other one said the holes were a major part of the problem, but there are other parts of the roof with cracks contributing to the leaks as well. What's the best way to have the tenant pay for the damages? I am approaching an attorney as well to get some inputs.