Cathedral Ceiling Ventilation, Attic Vents and Air Circulation

Depending on your house interior and roof framinginstalled on top of the finished ceiling. "Twist" is for
design, cathedral ceiling ventilation can be treatedextreme conditions, which in regular attic are
as an independent or attic ventilation relatedeasier to spot, and much cheaper to correct.
condition.1. Insulation - if properly installed between the
Majority of problems with cathedral ceilingsrafters, on top of the ceiling material (drywall,
develop in structures where the ceiling framing,plaster, paneling sheets, etc.), there should be
and roof framing are the same. What it means,approximately 2" of space left above it. This
that there's no accessible attic between the ceilingspace allows air to flow between the bottom and
and roof surface, only narrow, rafter / trusstop of the roof.
space which should be partially filled with insulation.Ideal installation would include vent chutes /
In some homes, there is a partial attic, and youbaffles, secured to roof decking, which ensures
can see / look into the ceiling structure fromproper insulation spacing and undisturbed air flow
accessible part. "Safer" (from the cathedral ceiling(critical in cold climates).
ventilation point of view) types of vaulted ceilingsContractors who misunderstand principles of
are the ones, which have a separate from roofproper attic ventilation, never use vent chutes,
framing structure, which allows air to circulateuse more or thicker insulation than required,
more freely.packing it tightly into the rafter space, blocking
But let's talk about this first type. Depending oncompletely air flow, and causing... costly
severity of the cathedral ceiling ventilation"headaches".
problem, you may, or may not see its2. Roof bottom vents - because each rafter
consequences for a long time.space is like a small, individual attic, it needs fresh
Some of the conditions, you'd be noticing are:air feed, which in most cases comes from roof
- roof surface deformation above the cathedraloverhang - soffit. With a variety of roof soffit
ceiling section of your house,designs, it is hard to suggest any particular type
- moisture stains on the cathedral ceiling surface,of vent, but continues one would probably cover
- moisture dripping from recessed light fixtures orall possibilities and ensure that each rafter space
electrical boxes on the cathedral ceiling,will receive fresh air. If there's no overhang /
- moisture / water stains stains along the topsoffit, "vented drip edge" can be utilized.
section of the window located in the wall3. Roof top vents - depending on how your
supporting lower end of cathedral ceiling,vaulted ceiling ends, different types of vents
- dark stains (also known as ghost marks).would be required: - if it goes all the way to the
All of the above conditions are curable, butroof top / ridge / peak, where other side of
depending on the extent of damage, it might getcathedral ceiling starts, the only type of vent that
expensive (lack of proper attic ventilation is ashould be installed is a ridge vent.
main cause of mold growth and ice damming).Some roofers prefer static roof louver vents, and
Basic principle for cathedral ceiling ventilation isif installed between every two rafters, it will do
pretty much the same as for any attic with athe job - but it doesn't look nice, especially when
"twist" to it.you have a long ridge line.
To prevent possibility of moisture condensation,If your cathedral ceiling vents into an open attic,
you need constant air movement between theany type of a properly installed vent will do, as
bottom and top of the roof, through the spacelong as it provides adequate output.
between rafters / above the insulation layer