Or copy this URL:
https://www.metalroofing.com/spirit/comment/4649/find/
First of all, there is more to proper ridge venting than just leaving things open. You still need something in place to prevent water and snow from blowing up and in. You need to contact the roofing manufacturer to see what they suggest for proper ridge ventilation.
However, if you're asking whether dormers should be vented ... I am assuming the main ridge is vented and you just want to know whether to vent the dormers too. This depends upon your exact construction. If there is soffit vent on the dormers then, yes, I would put in ridge vent. If there is not soffit vent, I would not put in ridge vent as it could possibly disrupt the airflow in the main portion of the attic.
I hope this helps. I am not sure I have fully understood the intent behind your question.
11/21/2004
11/21/2004