condensation,gable roof,knee walls

Guest User
3/4/2006
new metal roof,29ga.?,installed over 30lb felt, 3/4 tongue and groove sheeting,2x4 rafters. 3 1/2" r-11 insulation between rafters. 8x8 gable vents. no soffet or ridge vents. 7/12 pitch. Home is being totally remodeled, no drywall yet,all outside walls and roof is insulated. We are having condensation issues on bottom of sheeting . not a problem with previous asphalt roofing. Could this be due to not having ceiling installed downstairs and or upstairs. Seems to be a problem mainly during temp. changes outside, not just when steadily warm or cold outside. Any and all help would be greatly appreciated, before finishing inside.Can provide pics or any other info needed. Thanks in advance. vince
Allan Reid
Dura-Loc Roofing Systems, Inc.
3/8/2006
I am assuming that you are turning a former gablke vented attic space into living area. Initial problem is from being under construction with high humidity and you have no air barrier (10 mil poly)on the inside face of the insulation. Warm moist air is moving through and condensating. Second issue is that you did not provide a vented air space of min 1" between the insulation and roof covering. Third issue is that R11 is no where near the required insulation for a ceiling and should be R40.
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