Are lap vents any good?
Felt Lap Vents are considered by many as the most popular and easy-to-fit products available on the market today. Inserted on the inside of the roof, they are a DIY product that can be easily and cheaply installed. They are extremely effective at treating condensation problems in attics and lofts.
What is a lap vent?
Felt lap vents increase the amount of ventilation into existing roof spaces and lofts. They are an affordable solution for those looking to reduce the build-up condensation in their roofs and attics. They are especially useful in properties that have poor ventilation and that are susceptible to damp as a result.
Where do you put a lap vent?
Initially it is recommended that one Felt Lap Vent be placed at every other rafter spacing, at low level (as near to the eaves as possible) on both sides of the roof space to ensure a cross flow of ventilation and monitor the condensation levels.
Is too much attic ventilation bad?
More Attic Ventilation is Good Insufficient ventilation can lead to moisture problems during the winter and decreased energy efficiency during the summer but too much ventilation can be just as bad, if not worse. That said, air resistance and interference (such as vent grates) reduces the area of true ventilation.
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.
How are attics ventilated?
Attic ventilation works on the principle that heated air naturally rises, primarily utilizing two types of vents: Intake vents, located at the lowest part of the roof under the eaves, allow cool air to enter the attic. Hot air exhaust vents, located at the peak of the roof, allow hot air to escape.
How do I stop condensation in my roof space?
Two processes must be in place to effectively stop condensation in the loft space. Firstly there must be adequate ventilation. Secondly , you must remove or reduce as much as possible warm moisture laden air rising into the loft. To prevent warm air rising into the loft, ideally, a vapour barrier would be fitted.
Why is my roof felt wet?
What Causes Condensation In The Loft Or Roof Space? Warm air can contain more moisture than colder air. When this warm moist air hits the cold air in the roof space, water droplets condense on the nearest cold surface – the roofing felt.
Why is the felt in my loft wet?
Warm moist air enters the roof space through gaps in loft hatches or where bathroom plumbing or other services go through the roof space. When this warm moist air hits the cold air in the roof space, water droplets condense on the nearest cold surface – the roofing felt.
How do I stop damp in my attic?
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.