Basic Roof Repair
Tiles can fracture, spall, or drop out.
Don't work on a tile roof by yourself unless you are very comfortable on a roof. They are slippery and dangerous. Hire a contractor to do it if you have any doubts.
Shingles can split, fall out, or decompose.
Replacing wooden shakes is a do it yourself job, if you're fairly handy and have the right tools. A shingle-puller is almost required (a flat-bladed tool with a set of hooks on the end that catch and cut the nails holding shingles in place), and a good, comfortable hammer.
Cracked or missing slates will leak
Slate roofs are heavy and expensive, but they will last almost forever, if cared for. Slate as well should not be worked on unless you are comfortable working on a roof. This is especially true with the steep pitch of some older houses. Get help or hire it done.
Corrosion can weaken roofs
Metal roofs (terne, tin, copper, steel, etc. ) can be long lasting and low-maintenance if installed correctly.
Preparing for a new roof
Strip the roof if there are:
Article from: www.phouka.com