How do deal with a wet attic space
Recently, a homeowner had called our roofing company, with real concern over his attic space being, soaking wet to the touch. He thought maybe the roof had been installed improperly, so he requested that we come over and investigate the issue.
Arriving at his home, I had noticed a few important things. It was a newer home, 3-5 years old, and the roof pitch was fairly steep, 8/12 pitch . There was adaquate low end venting, (birdblock vents), and there appeared to be ridge venting installed.
As we had entered the attic space, it was noticeable that the underside of the plywood was wet to the touch and had been dripping for some time onto the blown in insulation. We had also noticed that it seemed a little warm in the attic space, while it was 30 degree’s outside.
We had discovered several heat sources in the attic space ie….light fixtures, waterheater vent pipe, etc….. The home owner had gotten up close to the ridge vent from inside the attic and noticed that there was no light that could be seen through the ridge vent, which he thought was a little odd.
We had decided on installing a few turbine vents along the backside of the roof line, unseen from the street. Due to the appearance of turbine vents, the inadaquate air movement in the area and the homeowners association policies, it was decided upon to install AF-50 attic vents along the back side of their roof.
Right away the homeowner had called and said he could definitely feel a temperature drop in the attic space. It is very important to try to maintain the same temperature in the attic space as the current outside temperatures.
It appears that the roofing contractor who installed the attic vents, had not cut back the plywood 2″-3″ leaving a significant air flow space which can contribute to a wet attic. When the temperatures dropped outside, the attic space remained warm and condensation began to form on the underside of the plywood.
Unfortunately the homeowners had to have a contractor suck out the wet insulation, as mildew started to form. They also had new gable vents installed at the gable walls. The homeowner had been very vigilant at keeping ahead of issues that could have became even bigger problems down the road, for instance, “Mold.”
Ventilation has such a huge impact on condensation issues. There has to be plenty of low end venting at the eaves but just as important is the upper end venting near the ridge line.
We have had several freezing days since the vents were installed and the condensation did not reappear.
If you are having similiar condensation issues, here in Western Washington, feel free to give us a call and we can diagnose the problem and find a solution.
Gerry Ray–(253) 394-6687
I really wish there were more atrilces like this on the web.
I didn’t know that.