Old houses can have a number of problems. If you are concerned about keeping water out of your house then take a look at this. This is a picture of an old brick chimney that was originally used to heat this century old home. Notice the old red brick you can see inside the hole. Someone decided to abandon the use of the chimney & cap it with mortar so it can no longer be used. Notice the old metal flashing. It is rusted out and there is a hole in it. Water is going to make its way into this hole and run into the house down the chimney and underneath the roof shingles. Also notice how the shingle on the lowest side of the chimney (Far right side of photo) is butted up against the chimney. At this location the flashing should actually be on top of the the shingle allowing water to shed.
If you have this same problem at your house then make sure you contact a roofing contractor that is licensed and insured to do the repair.
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