Continuous soffit vent retrofit - Page 3

Daox · 08-13-15, 12:16 PM

Why would you want a warm roof?

Elcam84 · 08-13-15, 02:01 PM

What he is talking about is where the insulation is. In hot humid climates they now recommend that the roof itself being the insulating boundary not the ceiling. The attic becomes a tempered zone. This reduces heat gain into the house and especially makes the house cool better at night as all that heat in the attic isn't radiating down into the house all night.

Up north attic venting is even more important than in the south because when the roof gets warm it can melt ice and snow and cause ice dams that can ruin a roof and house and cause all kinds of moisture damage and mold growth. The roof needs to stay cold regardless of weather it's vented or not. So on an insulated roof deck it needs to not let heat out to the outside to cause ice dams.

Here where it's hot most of the year it's an energy usage issue not really a damage to structure issue.

nibs · 08-13-15, 04:02 PM

The house we are abuilding, is bermed on 3 sides and has a flat roof over 50% of house, we are building warm roofs because of the energy loss ( zone 4 ) . The condition we must guard against is the underside of the roof sheathing reaching the dew point, and causing/allowing rot. So our insulation must be pretty substantial and must be in full contact with the sheathing. I am insulating the flat part now & at 100 deg F am finding it pretty tough to be thinking of snow. Not too worried about ice dams since you could park a semi on the roof. This year the room under the finished part of the roof will not be heated so no worries, but soon we will be too old to tour off to Mexico for the winters so we gotta get ready.

08-13-15, 12:16 PM	#21
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Why would you want a warm roof? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

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08-13-15, 02:01 PM	#22
Elcam84 Apprentice EcoRenovator Join Date: Jun 2013 Location: TX Posts: 275 Thanks: 2 Thanked 31 Times in 24 Posts	What he is talking about is where the insulation is. In hot humid climates they now recommend that the roof itself being the insulating boundary not the ceiling. The attic becomes a tempered zone. This reduces heat gain into the house and especially makes the house cool better at night as all that heat in the attic isn't radiating down into the house all night. Up north attic venting is even more important than in the south because when the roof gets warm it can melt ice and snow and cause ice dams that can ruin a roof and house and cause all kinds of moisture damage and mold growth. The roof needs to stay cold regardless of weather it's vented or not. So on an insulated roof deck it needs to not let heat out to the outside to cause ice dams. Here where it's hot most of the year it's an energy usage issue not really a damage to structure issue.

08-13-15, 04:02 PM	#23
nibs Apprentice EcoRenovator Join Date: Jun 2010 Posts: 206 Thanks: 1 Thanked 18 Times in 17 Posts	The house we are abuilding, is bermed on 3 sides and has a flat roof over 50% of house, we are building warm roofs because of the energy loss ( zone 4 ) . The condition we must guard against is the underside of the roof sheathing reaching the dew point, and causing/allowing rot. So our insulation must be pretty substantial and must be in full contact with the sheathing. I am insulating the flat part now & at 100 deg F am finding it pretty tough to be thinking of snow. Not too worried about ice dams since you could park a semi on the roof. This year the room under the finished part of the roof will not be heated so no worries, but soon we will be too old to tour off to Mexico for the winters so we gotta get ready.