You do not need to call a roof specialist every time there is a leak that originates from the top of the house. You can handle these issues yourself, with a little skill, balance and patience.
Understanding the damage to the roof tile
Firstly, you must assess and understand the damage inflicted on the roof. A good possibility is that the leakage was caused by weather conditions or the roof was not built properly to start with. Poor construction coupled with extreme temperatures can result in loose roof tiles and leakages.
Find the mouth of the leakage in the roof, then you can understand the extent of the damage. However big or small the problem might be, you will have to remove the surrounding tiles. On removing the roof tiles you should find the hole that is causing the leak in the roof. Then you will know how much repair work is needed to fix it.
Removing roof tiles
Before starting work on the roof tiles lay a tarp on the ground below. All the debris can be accumulated on it, which can be easily discarded later. Use a tile ripping bar or a square-nosed shovel to remove the roof tiles. If there is extensive damage it is better to call a professional. However if the leak was due to some missing or old tiles you can simply replace them with new ones.