Hot roof with 2 lb. spray foam on a 3/12 pitch roof
I’m in Toronto And I’ve built a house with a roof pitch of 3/12. I’ve been told by every insulation contractor that I would have to do a hot roof 2lb sprayfoam application. Reason for this is that the city of Toronto requires r60 in the Roof/attic. If I tried to put in loosefill or batts I’m told there will be no room for air circulation and I’ll get mold. Im going to put 5inch of 2lb sprayfoam ( Honeywell Solstice LBA or Insulthane Extreme In Canada) that will give me r31 or r32 on the underside of my roof . The city is saying I would have to spray to make it r60. Sprayfoam people saying that it’s a waste of money to add that much foam and the r31 is more then enough and will do a better job then r60 batts/fill. If the city won’t let me get away with the r31 hotroof can I stick some roxul r30 batts to the underside of the roof and under the sprayfoam so I can pass my insulation inspection ? I’m not sure if I can afford the extra cost of the sprayfoam for the Roof and even the sprayfoam people are saying it’s not necessary. The rest of the house exterior walls from the basement to the roof will be sprayed as well. Any suggestions or where I might be able to point the city in the right direction would be a great help.
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