Too often mechanical ventilation ducts from bathrooms kitchens or laundry rooms deposit warm moist air into the attic instead of outside the building envelope.
No attic vents.
Without baffles blinders that prevent outside air from crossing over the vent a ridge vent may create almost no ventilation at all.
For the same reason insulation shouldn t touch the roof s underside.
He loved big eaves.
Without adequate ventilation moisture rises with the hot air and forms condensation on the inside of the roof deck.
The design of many older houses omits eaves which maximizes the amount of sunlight.
Typically you would have a gable vent on each end of the attic.
If you have an attic with no soffit vents but 2 unobstructed gable vents then you will probably be ok on ventilation.
Gable vents may circulate air through only a small percentage of your attic.
This can lead to a number of serious and expensive problems.
The majority of roofing experts agree that ridge vents are the most effective and cost effective roof vents available.
Covering up the soffit vents with loose fill or batts which can happen if you stuff insulation along the eaves is a huge no no.
Problems when roof has no overhang.
Normal vented air likes to enter the attic lower down near the bottom third of the attic and as it passes through it will exit higher up near the top third of the attic space.
This moisture is released into the air inside the house from bathing cooking plants laundry and other causes.
A combination of air sealing and insulating the attic floor while providing ventilation considerably reduces the potential for condensation as warm moist air is less likely to enter the space and condense on cold surfaces.
So if you have shallow eaves with a flat soffit you have a very small overhang that has a flat bottom.
A great example of great wide eaves are the homes of frank lloyd wright.
For proper ventilation it isn t enough for air to simply get into your attic.
How to vent an attic with no eaves the function of soffit vents.
Construct a soffit or eaves overhang combined with assuring that an opening is provided all along the top of the.
On the principle that hot air rises the accumulated heat and moisture would rise to the attic and out the roof vents.
The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow.
Improperly installed attic ventilation cannot address two important aspects of indoor comfort.
For an attic without soffit vents you may have the option to use gable vents instead.
Soffits are the underside of the eaves.
When the attic becomes part of the home to be heated and cooled open wall gable vents and roof vents are no longer feasible but the underside of the roof the sheathing and rafters can still get.