Is there some code requirements that require venting? Or some advantage, maybe in cooling?
Heat destroys composition shingles. Not sure how prevalent they are in Cali. Sounds like an excuse to demonize a petroleum product, and shift blame from a lack of water, and bad forest practices.
In the WA county they require attic venting fans that are on a timer. Also an all house fan that goes off on a timer as well since they think that old folks here don’t have enough sense to open a window in a house that’s basically hermetically sealed because of requirements.
If its not vented, humidity builds up and you get mold and other nasty stuff.
Cooling a sealed attic with the summer sun beating down on it? That would triple your summer electric bill. The reason for incoming soffit vents and outgoing gable vents is to keep the attic from getting way hotter than the outdoor temp and also prevent mold from humidity.
I wonder if operable vents along with grid fed smoke detectors and relays to close the vents would work? Just something else to inspect and maintain of course.
Soffit/gable vents with metal screens would do a lot. Soffit vents are slotted vinyl and may have fiberglass screens.
The International Residential Code specifies that conventional attics be ventilated at a rate of 1 square foot of vent opening for each 150-300 sqft of attic area depending on the region in which the house is built. Openings are roughly equally divided between eaves and ridges/upper roof areas to attain convective air flow to draft hot air out of the attic.
Closed attics are generally accomplished by spraying foam insulation in rafter bays and deleting soffit and ridge openings, deleting insulation in ceiling joist bays as well as providing a small amount of conditioned air flow. In essence, the attic becomes part of a home’s conditioned volume.
Both have their plusses and minuses. An un- or under-vented and/or improperly insulated attic in my part of Texas can easily heat up in excess of 160 degrees on relatively normal summer days. In winter, it retains moisture that can compress insulation and promote mold growth.
Closed attics are technically more efficient but foam applied to the underside of a roof deck can hide leaks until they reach a point of catastrophic failure. Insurance companies are beginning to deny coverage for these types of installations where I live because of that.
I know it keeps the damp out of the air space..
short of that, I don’t know.
Depending on the climate, an unvented attic can rot. An unvented attic in warm clmate can get really hot.
My vents have screens that won’t allow small particles to enter.
Maybe double screening in some areas would work. They definetly need some anti-fire construction like Chicago did after their great fire.
It is code in my state which follows a national code.
“Is there some code requirements that require venting? Or some advantage, maybe in cooling?”
the purpose of attic venting is to keep warm moisture from the interior of your house from building up in the attic and then condensing on the underside of your cold roof during the winter, esp. in humid climates, and thereby rotting the roof sheeting ...
many decades ago, a friend’s father in my neighborhood thought he was being energy-smart by having his gable vents sealed off ... a few years later, he found out all of his roof sheeting had rotted and had to be replaced ...
Where I live, in addition to those things you mentioned, vents help prevent black mold in attics.