Completely replacing a leaky roof is a very expensive repair job. Unfortunately, not everyone can afford to undergo such repairs at just any time. However, letting the roof continue to leak is not a good option either, as this can cause more damage on the interior of your house, and in the end, cost you more money. Some cost effective ideas help preserve the rest of the house until you save for a new roof.
After any roofing job, there are likely going to be several waste shingles from the job left over. Make sure you keep these. Alternatively, if you move into a house with an older roof and you can't afford to replace the whole thing, buy a single bundle of matching shingles. If you find a leak in the roof, you can try replacing the individual shingles where the leak is located at a cost much less than replacing a roof.
All-purpose roofing compound patches most small leaks in a roof for an affordable price. The key to using this type of product is finding out where the leak is actually coming from. Trace the leak back through your home and into the attic so you know where to look on the roof for the holes or cracks in the roof. Patch it with some roofing compound or roofing cement to try to plug the leak.
Silicone sealant can be very helpful if a leak is coming in through a point of entry other than a typical nail hole in a roof. For instance, if you have a leak coming in through an opening in a J-channel placed around a vent, you can use typical silicone sealant to plug the hole. This is another fix method that might not be permanent, but if you have found the water's point of entry it should certainly buy you some time.
Sometimes the cause of a leaky roof will be readily seen once you actually get up on the roof and inspect it. If you have the proper ladders and are comfortable on the roof, go up and ensure that there are no obvious problems. Flashing that is peeling up, seals around pipes or vents that are worn, overflowing plugged rain gutters and other problems can sometimes be spotted and repaired on the spot once you're on the roof.