attic ventilation

I inspected a home recently, in the attic there was plenty of insulation and everything looked dry. there were rafter vents in every 4th “cavity” that seem to corresponded with the location of the vents in the eaves. What I am questioning is are rafter vents needed in every rafter or just select few?

The more the better.

That used to be how it was done, those with gable vents. A better setup is a continuous soffit vent with a continuous ridge vent, so all of the underside of the roof has a convection effect and the roof stays as cool as possible.

so it is acceptable but not ideal. In this particular house there was a continuous ridge vent, but only a few rafter vents. Would you recommend adding more rafter vents or since there are only a few eave vents it wouldn’t be necessary.

State what you observed and move on.

If it were my home I would like to see baffles in each area.
See attachment.

InsulationBaffle.jpg

The ridge vent is really only doing its job in the rafter cavities that have the soffit vent. I would write something like “It was noted that while there is a continuous ridge vent, the soffit was only vented at every 4th rafter cavity. Ideally, a continuous soffit vent would work more efficiently with the ridge vent to keep the roof as cool as possible and extend the life of the roof covering.” And move on.

thanks for all the help AWESOME