Warning, this posting got to be a little longÃ¢â‚¬Â¦ sorry! ]
In May we had a new roof put on our 1923 colonial house in CT. I like the contractor and think he did a nice job.
BUT come winter, IÃ¢â‚¬â„¢ve just discovered a new problem: water is dripping from the shingle nails onto the attic floor and more importantly onto all our stuff up there that could get damaged.
I discovered the dripping in early December and have seen it happen 2-3 times so far. It seems to be from condensation on the cold nails. It happens most/worst when the temps go below freezing at night but go up into 40Ã¢â‚¬â„¢s in the day.
The OLD roof was 3 layers (1 cedar shake + 2 asphalt) and lacked a ridge vent. It NEVER HAD CONDENSATION dripping problem. In fact, attic always seemed like the driest part of house.
The NEW roof has all new plywood deck, plus 1 layer of Timberline architectural shingles, and a ridge vent. So the theory is that the condensation is due to the NEW THINNER ROOF and possibly NEW RIDGE VENT.
With fewer layers, the roof itself provides less insulation by itself. And the nails may stick through more than before (not sure about that, but itÃ¢â‚¬â„¢s possible). Also, attic seems maybe colder than past years, perhaps due to the new ridge vent.
THEORY: Colder nails, sticking through further, leads to dripping.
(NOTE: Only the nails that come through the shingles are wet. There are many other old nails that they banged down before the new roof was installed and those are all dry!)
Q: Does this sound like good theory?
Q: If so, how should we address the problem?
My contractor is against getting rid of the ridge vent and I understand his reasoning. I suggested blocking the ridge vent from inside during the winter months and he didnÃ¢â‚¬â„¢t seem to like that.
But his suggested solution is really a band-aid. He wants to nail FIBERBOARD to the underside of the rafters, but leaving openings at top (near ridge) and bottom (near eaves) for air flow. The fiberboard would catch the drips before they fell to the floor.
But I have some concerns with this idea. The fiberboard seems like itÃ¢â‚¬â„¢ll absorb the water from the drips which doesnÃ¢â‚¬â„¢t seem so good, possibly harboring moisture or mold. And I wonder if adding this layer under the rafters will be good thing to keep my roof healthy and to keep the attic cooler in summer & warmer in winter.
Another thought I had was if the ventilation could possibly be worse now, even with the new ridge vent. IÃ¢â‚¬â„¢m thinking the new roof is tighter & more sealed (weather watch?) at the gutters/soffits than it used to be. We never had or needed soffit vents before, but maybe we need them now.
Any advice would be greatly appreciated!