Water dripping from roofing nails in attic
On Nov 23, 11:20*am, Ben wrote:
I was up in my attic this morning and noticed little bits of ice lying
around---small balls, perhaps 1/4" in diameter. *What seems to be
happening is that water is dripping from the roofing nails, then
freezing into the little ice balls. *Only some of the nails are wet;
most are dry. *I would guess that that makes it more likely that the
moisture is coming from the outside rather than from condensation from
air from inside the house. *Is my logic right? *Is this normal, or
should I take measures to repair?
Thanks in advance!!
-Ben
Ben: It sounds as though your attic is not ventilated correctly?
Assuming your house is has insulated ceilings with an appropriate and
sealed vapour barrier on the warm side of the insulation ?
The condition could be serious and cause rot/mould.
Normally what is happening is that warm and therefore moist air from
the house, some of which will inevitably leak into the attic is
condensing on the cold nail tips.
The requirement here, for example, is that there be venting of 0.3% of
the floor area and that it be cross ventilation.
That means that for each 1000 square feeta of area there be a minimum
of 3 square feet of ventilation (not all in one place) but spread
around as soffit vents, vents in the eaves or even roof vents.
If you have insulated ceilings make sure the insulation does not get
wet from such drips. Wet insulation is not only useless it can cause
rot and bad ceilings.
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