Ice damming is caused by the warmer attic space melting the snow down to the cooler eaves where it freezes.
No vents in attic.
This moisture is released into the air inside the house from bathing cooking plants laundry and other causes.
Too often mechanical ventilation ducts from bathrooms kitchens or laundry rooms deposit warm moist air into the attic instead of outside the building envelope.
Focus on the other ventilation you have in the attic.
The design of many older houses omits eaves which maximizes the amount of sunlight.
Install low gable vents located above the top level of the attic ceiling insulation use eye brow vents that are on the top of the sloping roof surface near the soffit eave area.
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.
Your roof vents may not look anything like the ones shown in this article.
Your actual living space is sealed.
The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow.
Problems when roof has no overhang.
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.
The majority of roofing experts agree that ridge vents are the most effective and cost effective roof vents available.
Without baffles blinders that prevent outside air from crossing over the vent a ridge vent may create almost no ventilation at all.
If there are asphalt shingles on your roof the attic must be ventilated to comply with the terms of the.
Your roof may have a ridge vent which is a low profile continuous roof air vent running along the peak of the roof.
If you are installing a new roof consider a drip edge vent.
You can use a shingle over vent at the bottom or mid roof mid roof being higher up than the potential ice damming.
Don t avoid ventilating your attic for fear you re letting cold air into the house.
On the principle that hot air rises the accumulated heat and moisture would rise to the attic and out the roof vents.
Without adequate ventilation moisture rises with the hot air and forms condensation on the inside of the roof deck.
Gable vents may circulate air through only a small percentage of your attic.
Properly vented attic space will not do that because its theoretically the same temp as it is outside.
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.
Look at your eaves and roof.
If you don t see any attic vents on the roof or in the eaves you need to add some.
How to vent an attic with no eaves the function of soffit vents.
