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Spray foam eaves

Thomas Vermeiren | Posted in General Questions on

Hi All, 

We are getting our roof spray foamed in about a month. I’d like to leave no stone unturned and ensure the foam contractor doesn’t miss anything. 

Apologies if I am not using the right terminology. Attached is a photo of where the roof / rafters meet the wall. You see (from top to bottom): subfloor, joist, another layer of boards or maybe a top sill, joist, bottom of eaves. 

Can you please share what exactly needs to be spray foamed, i.e. all the way down the eaves? Can I prep the area before they start to maximize chances of success? 

Information in case necessary: Northern NJ / zone 5, unvented roof and will be conditioned in the future. 

Many thanks,

GBA Prime

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    1. Expert Member
      Akos | | #2

      One thing to watch is with older all brick or brick veneer houses. In a lot of those the space behind the brick is vented into the soffit area. When you spray foam, you don't want to plug these, so installing baffles to contain the SPF is important. You want to keep this vent space open for brick and sheathing durability.

      1. Thomas Vermeiren | | #3

        Thank you - great point.

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