Further to what Robbo has said, if you use BREATHABLE felt you do not need any other form of ventilation (i.e. soffit vents or over fascia vents). Breathable felt is very popular now as it is clean and light to handle.
Do you need ventilation with breathable membrane?
Installed to the outer side of the insulation, over or under the counter-battens on a pitched roof, breather membranes allow water vapour to escape from inside a building. Often without the need for ventilation.
Are roof vents necessary?
Without proper roof ventilation, you allow the attic to remain at a high temperature. This can damage and crack your shingles well before they should be showing signs of damage. Go with the Flow. Roof vents create proper air flow, which reduces moisture that can build up inside an attic.
Is Roof venting required by code?
Enclosed attics and enclosed rafters are required by the California Residential Code to have proper ventilation.
What happens if you don’t vent a roof?
They say that poor or non-existent ventilation might cause attic temperatures to rise to 150 degrees or higher in the summer. That can lead to damaged shingles and other roofing materials as well as a buildup of condensation and development of mildew and mold.
What is the best breathable roofing membrane?
Klober Permo Air is the most breathable felt on the market and is the perfect choice for unventilated roof spaces or climates where condensation is likely to be a problem.
Does breathable felt stop condensation?
Roofing felt is impermeable to water so it will not allow moisture to escape from the roof. Breathable membrane does allow water vapour to escape from the roof space but if other circumstances are working against it then it may not be sufficient on its own to prevent condensation.
Can a roof have too much ventilation?
The two main dangers associated with too much ventilation involve roof damage and increased utility bills. If you have too much air circulating, your roof will collect moisture causing damages that will weaken spots and then cause leaking.
How do you tell if attic is properly vented?
How to determine whether you need better attic ventilation
- Look at your eaves and roof. …
- Touch your ceiling on a warm, sunny day. …
- Thick ridges of ice on your eaves in winter are a sign of poor attic ventilation. …
- Warm air that escapes living space also carries moisture that will condense on rafters or roof sheathing.
How many roof vents should you have?
How Many Vents Do I Need? The general rule of thumb in these situations is of roughly one vent per every 300 square feet of attic area if the attic has a vapor barrier. If not, there should be one vent for every 150 square feet. You will need to have 1 square foot of vent area for every 150 square feet of attic space.
What is the best roof venting system?
- BEST OVERALL: LOMANCO 12 in. …
- BEST BANG FOR THE BUCK: Broan-NuTone 3 in. …
- BEST RIDGE VENT: GAF Cobra Ridge Vent.
- BEST SOLAR VENT: Master Flow 500 CFM Solar Powered Roof Mount Exhaust.
- BEST HARD-WIRED POWERED: Master Flow 1000 CFM Mill Power Roof Mount Attic Fan.
What type of roof vents are best?
In most cases, we recommend soffit vents for intake and a ridge vent for exhaust. For homes that cannot have a ridge vent, box vents are generally the second best option for exhaust. And for homes that cannot have soffit ventilation, you will find that fascia vents to be your second best bet.
Do I need to vent my soffits?
Do I Need Vented Soffits? Soffit vents are not the only method used for the intake of air. If your roof has other means of venting and an adequate supply of airflow, there’s no need to add more. There are also roofs known as ‘hot roofs’ where the rafter bays are insulated and sealed.
What happens if you don’t vent attic?
Without ventilation, the attic will be warmer than the outdoor temperature, causing snow that lands on the roof to melt. As it drips down to the bottom of the roof, it will refreeze, forming dangerous ice dams. These can cause serious damage to your roof and gutters.
What happens if your attic is not vented?
But in homes without appropriate insulation and ventilation in the attic, heat migrates. … Meanwhile, because hot air is full of moisture, all that water hanging out in your attic is causing condensation to build up. Excess heat and condensation can cause major damage to your roof and roofing materials.
What are the vents on my roof?
Exhaust vents are installed at the top of the roof. Their primary job is to provide an unobstructed exit for the heat, hot air, odors and moisture trapped in your attic.