How to check your roof for a leak
Most roof leaks are hard to find and the hardest part to repairing a roof leak is finding where the leak is. You can tell your roof is bad if there are water stains on the ceiling and walls and shingles are missing or damaged. You will want to find the leak before the whole roof needs replaced. Water typically leaks in through missing, worn or broken shingles. Water can also leak in from skylights, chimneys, and through corroded or poorly sealed roof flashing.
In order to properly find the cause of a leak, you can do a simple leak test to see where the leak is coming from. You can see where a leak is coming from by going up to the attic and taking a look around or you can do an optical inspection of the roof. If you cannot find the cause of the leak, a water test is another effective way to find the leak.
To complete the water test, you will need two people. One person will need to go onto the roof with a hose and the other person has to go inside the attic with a pail and a bright light. You have to be patient when conducting a water test because it can take hours to find the leak. Let the water run slowly over areas you think are causing the leak. It can take some time before the water begins leaking inside. If this method does not show a leak within one hour, then let the roof material dry for 24 hours and try again on a different area. Once the leak is found, push a large nail up through the ceiling to mark the leaks location. You can also mark the roof so you know exactly where the leak is.
The exact methods for repairing the roof leak will depend greatly on the type of roofing material on your roof. Note: this method is not guaranteed and is solely another way to detect a roof leak. If you cannot find the leak after using these methods, call a professional.