Roof Ventilation

kimsprout1 asks,

My husband and I will be replacing our asphalt shingles with Architectural ones. The old ones started curling after 5 years. The house is now 15 years old and the shingles are cumbling in certain areas. However, we do not have any leaks at this time and would like to replace the shingles before this happens. It's a modular type, ranch style home, and the original shingles may not have been installed properly. The ridge cap is only about 30 feet long and our house is 56 feet in length. Some other contributing factors may be that we live in the trees, we're in Delaware so humidity is a factor, and we have cathedral ceilings so there is no attic or proper ventilation. I've seen a lot of products that can be installed under the shingles to aid in ventilation, but they are for houses with attics. Is there a product that would aid in ventilation on our style house. Thank you!

Our Answer

Hi Kim,

The problem here is that your roof is overheating from a lack of ventilation. Five years is a ridiculously short time to have to replace your shingles–a roof should last 20 years. The way to ventilate a cathedral ceiling is to make sure air flows above the insulation and below the roof sheathing. For that to happen, you need two things. The first is a continuous ridge vent that runs the entire length of the roof, not just 30 feet. The second is a soffit vent. If you don't have one, you will need to get a drip edge vent. What that does is extend the edge of your roof shingles and create a two-inch overhang in that space and where the air can get in. These two kinds of vents work together to move air properly and prevent overheating.

Good luck!

Tom