Anyone current on attic ventilation for Climate Zone 1?

[svetz]

Attic humidity is down from last month, possibly the window repairs, the additional attic sealing, drier overall weather (average humidity was 2% higher on the 26th), or <enter your guess>...

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[HRTKD]

Attic humidity is down from last month, possibly the window repairs, the additional attic sealing, drier overall weather, or Global Warming.

 

[svetz]

And the numbers keep on dropping....

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Inside humidity has been going down as well...

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[svetz]

In thinking about this, it makes sense... the air conditioning is running more so it's pulling more moisture out of the air. From this data, it looks like the attic is leaky enough to the inside and tight enough against the outside that it's humidity level has been going down too.

So quite possibly she won't have any problems through the summer/fall. It would be ironic if the problem occurs in winter as it does in other climate zones.

 

[svetz]

Humidity is up a bit again in the attic from last time, outside is ~90%, inside has been holding fairly steady peaking around 51% and the attic peaking around 56%. The dew point is still under the wall temperature so there should be no condensation. Time to do a visual inspection just to make sure ;-) But so far, so good.

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[svetz]

The visual inspection went well. Inside walls were not only dry, but wicked sweat away from my fingers. The delta between the room drywall temperature and the attic side temperature was about 3°F. The wall temperature in the attic ranged from 84 to 89°F and the underside of the roof deck a cool 95°F (thank you insulation!). So, looking good for the summer heat/humidity. Will still monitor through the winter too so I have a full year of data on it, might still have winter problems. If all goes well through the winter I'll just leave it hooked up with a dew-point and battery alarm. (love that GoogleDocs logging!)

 

[svetz]

Looks like I might be able to finally wrap up this thread, we finally got a "cold" morning here (46°F).

• humidity: 61 %
• temperature: 72.4 F

So, the sensor says the attic is staying warm enough to avoid any condensation.
But, I need to go over and visually verify there are no cold spots, it only takes one after all.

 

[svetz]

The temperature had risen to 51° by the time I arrived and the attic for most part was perfect, couldn't ask for better. Adding the insulation under the new metal roof and sealing it really did the trick for this climate zone.

The only issue was the fascia, it was 59°. No surprise really, it is only a 3/4" board about 8" high. There's no soffit to worry about. Oddly it was still dry, but the dew point should have been about 60°, possibly the wood was sucking it in.

Probably don't have to do anything, or just run a dehumidifier if the temperature is going below 50°, but thinking a couple of foam kits sprayed along the inside of the fascia wouldn't go amiss.