Roofmaster1981

Proper attic ventilation is essential. It prevents condensation and dry rot within the attic wood structure and wood substrates, prevents mould, and prevents warping of the plywood. Proper venting also extends the life of the shingles and roof membranes. Provide ventilation in a ratio of approximately 1:300 of the insulated attic area. Ideally air should enter the vented soffit, rise as heated in the attic, and exit near the peak of the roof. Some people incorrectly believe that ventilation is only to keep the attic cool on hot summer days, and have even been seen to close their roof vents off for the winter. Nothing can be further from the truth. One should vent the roof at all times of the year, day and night, in order to keep the attic temperature as close as possible to the outside temperature. Most importantly, the ventilation is absolutely necessary to prevent winter ice damming problems on sloped roofs

Roof shingles are the perfect place for moss and other algae to grow as this part of your home receives the most rainfall and has higher levels of humidity, making conditions perfect for moss to thrive. If there are large trees near the home that shade parts of the roof, moss can grow in abundance as there is a lack of direct sunlight. The accumulation of leaves and other organic debris can also aid in giving moss the nutrients it needs to grow.