Effects of mechanical fasteners and gaps between insulation boards on thermal performance of low-slope roofs

Laboratory experiments were carried out to examine the themal performance of metal-decked, low-slope roofs with polyisocyanurate insulation. The effects of thermal performance of fasteners through the roof insulation and gaps between insulation boards were measured. It was found that the effects of fasteners and gaps are to increase simulated annual heating and cooling loads by percentages about equal to the percentage reductions in thermal resistances at winter and summer conditions.