Retrofit Insulation Flat Roof

Cold roof a very bad idea.

Retrofit insulation flat roof.

Exterior roof insulation retrofit unvented roof covering the roof of an old house with a blanket of insulation makes the house more comfortable and it cuts energy use. This is then covered with a further weatherproofing layer. The concept can be applied to almost any flat roof and low slope or high slope configurations are possible. Image courtesy of building science corporation.

For larger roofs you may need to provide direct framing to framing contact. It makes a lot of sense if the rafter cavities are already insulated and it is most affordable when the roof needs replacement. I d like to add insulation to this truss space. The house has a flat epdm roof open chord roof trusses no ventilation and r 30 fiberglass batts with dubious installation quality wiring interrupts can lights swamp cooler ducts.

These new roofs can be either low sloped less than 2 12 functional roofs or high pitched greater than 2 12 architectural roofs depending on the expectations of the building owner. Cold roof systems are highly inadvisable as insulation from the inside will inevitably lead to the formation of condensation. But even though an unconditioned roof won t benefit from being covered in foam it will need to be detailed so that it aesthetically matches the rest of the roof retrofit work. To produce a hot roof rigid insulation is fitted outside above the weatherproofing.

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. Our insulation for existing flat roofs is ideal for extensions dormer roofs and includes a layer of either 25 50 75 or 100mm insulation board. The use of metal retrofit roofs allows the flat roofed buildings to undergo a transformation into a sloped roof building. It is ready to accept metal panels.

Batts between rafters in would require adding ventilation between the insulation roof deck. I m wondering if there are any effective solutions that don t rely on closed cell foam. Flat roof insulation by using our method of fitting insulation on the outside of the flat roof above the main decking boards but below the waterproofing layer we are able to protect the deck boards. It needs to be furred out with something so the trim details will later match.

In essence a steel framework is erected over the existing roof.