Posted - 5 April 1999 15:26
This sounds like a poor installation which has resulted in leakage of roof water. Check all penetrations (ie. plumbing vents, chimneys, roof vents, etc.) for proper flashing. Check roof/wall junctions for proper clearance (2" minimum). Look closer into why a moisture barrier between the OSB and shingles was not specified. If you cannot locate the exact location of your leak, a complete tear-off is recommended which should reveal more evidence as to the exact cause and correction.