A stitch in time saves nine, and this principal could not apply more to roof repairs. When damage is noticed, repairing it right away is usually easy and inexpensive, but wait until damage get worse, and you will be facing major repairs and expenses.
There are many components to a roofing system that can go wrong, tiles can crack, shingles can curl or be blown off, flashing can bend. All of these will lead to the same dangerous problem-roof leaks. You will not see the damage coming, usually. Water may be seeing in, but you will not see it in the house until it the water is coming into the interior of the home. At that point too much damage is already done.
The way to avoid this is to do periodic inspections of your roof. Get up there and look for damaged or missing tiles, shingles that are warped, flashing that has lifted. With adobe or rolled asphalt roofs, some of these problems will not be so visible, and you may have to pour water over the roof and look at the results.
Check any cracks with a flashlight. You should not be able to see the light from the inside of the house. Perform an interior inspection by walking around in the attic on the beams and looking for any daylight that shows through.
Check all of the beams for any signs of moisture. Finding moisture will not need to tell you where the problem is, however. Water may flow across the beam-follow the trail to find where it is coming from. If you find a crack or hole, drive a long nail through the roof close to the hole. Be careful of any wiring or cables. (This technique should not be employed for adobe roofs, as it will only create more damage.)
Next, squeeze toothpaste into the hole so that it goes to the outside. Toothpaste works for this purpose since it was washed away easily. If it is a very small crack, you may be able to just squeeze silicone gel instead of toothpaste, and let it cure to a hardness that will prevent a leak.
If you know you have a leak and the flashlight method does not work, you may be able to locate cracks by measuring the differences inside and apply them to the outside.
Once you have located a crack, you can repaper it from inside the attic, or replacing a shingle or tile on hate outside, depending on where the crack is. If you have major damage to your roof, you should have a professional tend to it. But to replace one or two tiles or shingles, it is a simple matter of removing the damaged one and replacing it. For an asphalt or wood roof, just nail in place on each corner.
Frequent asphalt can just be glued down if curling has occurred. If you have a tile roof, chip the damaged tile off and glue the same size tile down in its place.
Many times, however, just replacing the shingle will not cure the problem and you have to re tar that portion of the roof or even replace the roofing felt. Only attempt this yourself if it is a small job that you can get at easily.
The bottom line is examine your roof frequently and perform small repairs that you can before the damage Gert out of hand. When you consider the damage a roof leak can do to the walls, ceilings and flooring in your home, you will realize it is worth the trouble.