How do I create air flow for the roof that is being spray foamed?

How do I create air flow for the roof when spray foam insulation is used ?

  3 answers
  • Lynn Sorrell Lynn Sorrell on Jan 04, 2019

    Add vents,exhausts

  • The spray foam should not interfere with any of the roof vents. Who is installing the spray foam?

    • See 1 previous
    • Shingles need air circulation for optimum length of life. The insulation company "should" know what to do. I leave nothing to chance, so call your City inspector or your local permit office as they know your local Building code and can advise with certainty. In my area, they come out and inspect for free (call and make an appointment), and make suggestions if you are having issues. Then you can be positive you are making the right decision. Or . . . Give Mike Holmes a call, he is in Toronto! Love him! Miss his shows, he needs to do more!

  • Seth Seth on Jan 04, 2019

    JK

    You basically have two choices with cold weather attics:

    1. Keep it a cold attic -all the insulation goes on the attic floor over your living space, not under your sheathing. Some people might spray foam this area, but it is not necessary. Seal all ceiling penetrations into your attic to prevent warm, moist air from entering your attic. Continue to vent the way you are now.
    2. Turn the attic into a conditioned space because you are going to use it in some way. If it is heated or cooled, then you may want to consider insulation other than on the floor.


    Bottom line is, if you are not using it as living space, don't waste money and shorten the life of your roof by insulating it. Your biggest bang for your buck is to add additional insulation to the floor if it does not already have a double layer. You said you are working on an attic space. Do you plan on heating and cooling it? Check out this link:

    https://www.thisoldhouse.com/ideas/read-you-finish-your-attic