Air Sealing Electrical box knockouts
In an exsting electrical box can the knockout or “cutouts” in which the wire runs through be sealed off by spraying a small amount of canned spray foam. I would take the plate off, pull the wire out of the box as I dont want any overspray inside the box
Of course special attention would be given as to not “overspray” the inside of the box causing the wires inside the box to be envloped in foam.
Also can canned foam which claim to have a Class 1 Fire rating be used around a dryer ducting which goes through a cider block wall. The cutout in the wall is 2-3 inches bigger than the metal uct.
http://dap.com/product_details.aspx?BrandID=6&SubcatID=2
When I spoke to manfacture of the gas dryer he indicated the max temp for most resendtial gas dryers is around 180-200. Usually measured right behind the unit….Keep in mind the portion I was considering insulating the temp will be less. I will include the tech bulletin from DAP
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Matt,
To answer your first question, I wouldn't use spray foam to address air leakage through conventional electrical boxes. Because of the problem of overspray, your attempt may be considered a code violation by your electrical inspector. The volume of air in an electrical box is required to prevent overheating of the conductors.
Several manufacturers and distributors produce special electrical boxes or box accessories for airtight installations. These include:
Allied Moulded Products
http://www.alliedmoulded.com
Airfoil
http://www.airfoilinc.com
American Aldes
http://www.americanaldes.com
Energy Federation Inc.
http://www.efi.org
LESSCO
http://www.lessco-airtight.com
Pine Ridge Builders
http://www.energyblock.com
Shelter Supply
http://www.sheltersupply.com