Cathedral ceiling vents, attic vents, and air circulation
Depending on the interior of your home and the design of the roof structure, cathedral roof ventilation may be treated as a standalone condition or related to attic ventilation.
Most problems with cathedral ceilings develop in structures where the roof frame and the roof frame are the same. Which means there is no accessible attic between the roof and the roof surface, just a narrow beam / joist space that needs to be partially filled with insulation.
In some houses, there is a partial attic, and you can see / look inside the roof structure from the accessible part. The “safest” types of vaulted ceilings (from a cathedral ceiling ventilation point of view) are those with a truss structure separate from the ceiling, allowing air to circulate more freely.
But let’s talk about this first type. Depending on the severity of the cathedral ceiling ventilation problem, you may or may not see its consequences for a long time.
Some of the conditions you will notice are:
- deformation of the roof surface above the section of the roof of the cathedral of your house,
- damp spots on the surface of the cathedral ceiling,
- moisture dripping from recessed light fixtures or electrical boxes on the cathedral ceiling,
- damp / water stains stains along the upper section of the window located on the wall that supports the lower end of the cathedral ceiling,
- dark spots (also known as ghost marks).
All of the above conditions are curable, but depending on the extent of the damage, it can be costly (lack of adequate attic ventilation is a major cause of mold growth and ice build-up). The basic principle for cathedral ceiling ventilation is practically the same as for any attic with a “twist.”
To avoid the possibility of moisture condensation, you need constant air movement between the bottom and top of the roof, through the gap between the joists / above the insulation layer installed on top of the finished roof. “Twist” is for extreme conditions, which in a normal attic are easier to detect and much cheaper to correct.
1. Isolation – If installed correctly between joists, over ceiling material (drywall, plaster, panel sheeting, etc.), there should be approximately 2 “of space above. This space allows air to flow between the part bottom and top of the ceiling.
The ideal installation would include baffles / vents, secured to the roof deck, ensuring adequate insulation space and uninterrupted airflow (critical in cold climates).
Contractors who do not understand the principles of proper attic ventilation, never use vents, use thicker or thicker insulation than required, pack it tightly into the joist space, completely block airflow, and cause … expensive “headaches”.
2. Lower ceiling vents – because each beam space is like a small and individual attic, it needs fresh air supply, which in most cases comes from the overhang of the roof: ceiling. With a variety of ceiling tile designs, it is difficult to suggest any particular type of ventilation, but go on, one would probably cover all the possibilities and ensure that each joist space receives fresh air. If there is no overhang / ceiling, a “vented drip edge” can be used.
3. Roof vents – depending on how you finish your vaulted ceiling, different types of ventilation would be required: – if you reach the roof / ridge / peak, where the other side of the cathedral ceiling begins, the only type of ventilation that needs to be installed is a ridge wind .
Some roofers prefer static roof vents, and if installed between every other joist it will work, but it doesn’t look good, especially when you have a long ridge line.
If your cathedral ceiling is ventilated in an open attic, any properly installed type of ventilation will do, as long as it provides adequate outlet.
