I need to insulate a cathedral ceiling with no soffit vent. It is a the second story of my house, it was like an attic before and we had an addition added where the contractor basically picked up the pitch of the roof to add a little more space. There is no soffit vent but he put a ridge vent. I am finishing the interior of the job so my question is can I use fiberglass insulation without venting it? Again, it has a ridge vent but no soffit. I live in New Jersey and we have a decent amount of humidity here. My thought on it is before the addition there was no ventilation and no insulation. The home was built about 1925 and the roof and 2 by 6s are in great shape. Any thoughts on this? I appreciate it.

Install round vents in soffit between rafters.
Vents come in various sizes up to 3''.

Install rafter ventilatorbetween rafters from palte to ridge. This will give u air flow from top to bottom.

Install insuation.

Good luck

Chuck

You can install any kind of insulation, but venting is a critical part of a good part of proper cross venting. Does the construction of the joist running out to the fascia baord have a space on the top of it? There are plenty of ways (as mentioned above) to handle cross ventilation. "Tubes" on the side of the joist could work. A low profile "baffle" stapled to the sheathing of the roof, then installing your insulation just over that - all the way up.

The General on this should tell you what the specs are on this. You may only need so many joist bay's with this cross ventilation.

"At Eaves" or a fascia/soffit opening is essential. Ridge venting only takes care of one part. If you use fiberglass on a cathederal ceiling, make sure you use vapor barrier on the heated side.

Ridge vent but no soffit? How does air enter to flow up to the ridge vent?