To insulate above your roof sheathing the usual approach is rigid foam.
How to insulate your roof from the outside.
To make installation of the foam easiest screw a board over the very bottom of the existing roof edge.
I would start with determining the age of the structure.
To accomplish this a layer of insulation is used to isolate the warm house air from the roofing and a ventilated spaced is maintained above the insulation with outside air circulated through the space by installing a ridge vent to exhaust air and a vent at the bottom of the roof to draw in cold air.
Split your insulation so half goes in front of and half goes behind electrical wires.
Just make sure there is no rot in the roof deck before closing that all in with nice warm insulation.
The foam insulation can be put directly over the shingles or the shingles removed if there is a weight consideration.
Either eps or polyiso would be more environmentally friendly.
Source a stress skin panel company or prepare build your own.
Insulating an existing metal roof from the outside 1.
You must determine the load limitations on the existing roof trusses and understand they may require augmentation to.
Fill the stud cavity from top to bottom and side to side.
In new construction adding insulation on the exterior of the basement walls will do the following.
At that point what you are doing is building a r e m o t e wall read more about that here.
But insulation from the outside or sarking has its advantages.
Installing insulation that acts as a vapour barrier on the outside will not serve you well except if you add enough of it to the point where about 2 3rds of the total insulation is on the outside.
Minimize thermal bridging and reduce heat loss through the foundation protect the damp proof coating from damage during backfilling provide some protection against moisture intrusion make the.
However xps is the least environmentally friendly option because it is manufactured with a blowing agent with a high global warming potential.
With interior insulation the entire space between the rafters is filled with insulating material and then covered with a plasterboard or wood panel finish that is then painted or wallpapered.