How to insulate a metal roof without attic. Box out light fixtures. Cut panels on the roof. Install by using staples.
It is not the normal insulation type. Lay the plywood perpendicular to the roof joists and. You can install fiberglass insulation against the metal roof and prevent moisture problems if you cover it with a vapor barrier.
I would lean toward adding rigid foam either on top of the roof or on the inside under the joists if reducing headroom isnt a problem. This paper wrap is important to the health of the home by not allowing water to build up in the space between the sheathing and the metal roof. Lay insulation on paper liner.
Tips to install metal roof insulation. You will want to use this over rolled up or spray insulation because of the way that it lays flat and it can be easily installed under the metal roofing. One of the most common mistakes that diy homeowners make with their metal roof is that they do not lay down any type of paper wrap on the sheathing.
It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow. Install plywood or oriented strand board osb to act as structural roof sheathing. Depending on your climate youll need r 30 to r 49 to meet code which is 5 to 8 12 inches of polyiso rigid foam which is r 6 per inch.
Insulate and try to keep from reaching the dew point add a preinstalled membrane to absorb and release the condensation as it forms with the natural weather cycle traditionally weve insulated the roof panel to try and keep the temperature on the panel from reaching the dew point. Water is insulations enemy. Nail 1 furring along every rafter side against the roof deck.
Leave gaps between panels. Some homeowners choose to use unfaced fiberglass insulation batts.