We just built our first house. Or general saw us for the marks that we are and cut corners all over the place. Our ceiling started to leak when we first started to use our furnace. It leaked from the drywall into the house dripping at places where there were corners, light fixtures, or the ceiling met the walls. We found out our roof had no ventilation at all! So a ridge vent was put on and our vinyl siding had center vent put in the soffit to meet the county code. How that passed inspection, I don't know.
We thought this had fixed the problem. But after the last rain, one of the leaks still leaked a great deal into our bedroom. Though the other leaks seemed to be unchanged.
I am at a loss as to what to do. I suspect that it might have something to do with the insulation or perhaps the roof itself, but to me I can't see anything directly causing the prob.