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Roof Vent Installation

Question: We've been advised by a surveyor to increase the ventilation in the roof space by replacing a few of the slates with roof vents. We're pretty handy but not done anything on roofs at all. Our roof is asbestos cement fake slates. (It won't be high-level working as the house is a bungalow and the vents would be near the bottom of the roof.)

Answer: If you haven't performed any roofing you should consider a pro or finding a friend that has some experience. It is not an overly difficult project, but if the roof is not sealed properly, you will have no end of problems with water damage - a lot more than the pro would have charged for the installation of the vents. Also working with asbestos cement shakes requires a bit of practice.

I am somewhat surprised that the surveyor has recommended that the vents be near the bottom of the roof. Venting problems are usually because the hot moist air can't escape, not because the air isn't entering the attic space. To remove hot moist air, you want the vents closer to the top of the peak. However, if the surveyor believes that there is no airflow into the attic, it would make sense.

If the vents are needed at the low end, why not add vents in the underneath of the soffit? It is an easier project. You can purchase many different types of soffit vents from circular - where you just need to drill a large hole to square and rectangular - cut the soffit with a jig saw. You may have to pull back the ventilation from the soffit area.

Additional information on attic installation.