Venting a Porch Roof
josephny
| Posted in General Questions on
I have an open air covered porch along the front and part of the side of my house.
I am in the process of covering the rafters with 1×6 t&g pine and am concerned about the need for venting.
I understand that I can use vented soffit material between the girders and the outer edges of the rafters, but my understanding is that doing so will allow fresh air into the area between ceiling and roof sheathing, but I don’t know how to vent the hotter air out where the porch roof meets the side of the house.
Can someone suggest how to do that (if it’s needed at all)?
Here are some pictures.
Thank you!
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Replies
Joseph,
There is no reason to vent the porch at all.
Malcolm. What about insulating the ceiling to mitigate radiant heat? Maybe Joseph is in a mild climate, but covered porches can get pretty toasty in CZ3.
I'm in the Catskill mountains of NY, where the temp ranges from -10 to 105 F (the extremes are rare, I'd guess a typical year's range is 0-95).
I'd be very happy if there is nothing to be gained from venting the porch ceiling. Just to be clear, from the bottom up is: 1x6 T&G pine nailed to 2x4 on the 4" side, then 2x6, then plywood, then ice and water entirely over the ply, then asphalt shingles.
The heat will accumulate between the plywood and 1x6 pine board, but I guess the question is whether that heat is of any concern.
Thanks!
James,
The only concern (which has been widely dismissed) over not venting porch roofs is that it might shorten shingle life. Venting roofs is primarily done as a way to remove moisture that may accumulate. That isn't a concern when they are not constructed over conditioned living spaces and can easily dissipate what little incidental moisture occurs.
Heat build up is also not a worry, as it will not appreciably warm the open space below, or make its way into the house.
A warm roof is a dry roof, and a dry roof is a long lasting one.
Thank you so much for the explanation and advice!
I will cover the entire underside with the 1x6, including the eaves/soffit area.