Hi i am new to this site and have a question, I have a standard sized concrete garage on the back of my house with a sort of coragated roof (metal i think) and i'm turning it into a gymnasium, however i first need to fix all the leaks and damp and cold. If i set of a huge smoke bomb and go outside then mark all the places where the smoke comes out, then fill them is this the best way? Also what fill should i use that will work really well? Thankyou for any detailed replies.