Replies

1. Expert Member
   Malcolm Taylor|Aug 23, 2021 07:18pm|#1

   Joseph,

   There is no reason to vent the porch at all.

1. 
   Steve Knapp CZ 3A Georgia|Aug 23, 2021 07:47pm|#2

   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.

2. 
   Joseph Skoler|Aug 23, 2021 08:04pm|#3

   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!

1. Expert Member
   Malcolm Taylor|Aug 23, 2021 08:55pm|#4

   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.

1. 
   Joseph Skoler|Aug 24, 2021 06:32am|#5

   Thank you so much for the explanation and advice!

   I will cover the entire underside with the 1x6, including the eaves/soffit area.