Flat Roof With Exposed Rafters Insulation

If moisture is a major concern you can also install xps rigid insulation which offers superior moisture resistance.

Flat roof with exposed rafters insulation.

Isoboard thermal insulation fitted as a ceiling following the roofline allowing the opportunity to create additional space or a liveable loft conversion. Safety precautions and mistakes to avoid during garage roof insulation. On top of your roll roofing add several layers of comfortboard rockwool. The insulation for exposed rafters is installed on the exterior side of the finish ceiling.

Ibc dictates acceptable placement and composition of roofing materials in chapter 15 but describes required thermal efficiency of the roof in chapter 13 which references the international energy conservation code iecc the minimum required thermal resistance varies. Hack n stack sealed foam board between the rafters would be better since it s at least an air impermeable insulation but even that would require a vent gap below the roof deck to meet code and you d still be under r38 on that 2x6 rafters unless you fattened it out per holladay s recommendation. Images courtesy simpson gumpertz heger. Following ten years of extensive testing isoboard thermal insulation has developed a proven solution to fixing its thermal insulation boards above rafters trusses or beams.

The levelling tool enables. In the case of a cold roof structure the insulation is placed between or between and under the rafters or at ceiling joist level and the roof is ventilated by leaving a 50mm gap above the insulation which vents air to the outside. Roof insulation configurations for unvented rafter truss assemblies. This is often a layer of tongue and groove boards nailed to the exterior side of the exposed rafters.

Insulation boards are sandwiched between rafter and counterbatten that are connected with super 7 roof fixings. Breathing roof with low resistance lr underlay with this option insulation fully fills the rafter space without an airspace between the insulation and type lr underlay. It is top quality and the most cost effective product for your flat roof. You can expect to pay about 55 100 sq ft.

For a 1 inch board equivalent of 6 r value. Insulation between the rafters can be designed in two ways. Resistance to compression 943 psf osb and then some more roofing.