As this requires fitting insulation above the rafters the roof covering will have to be removed in order to fit the insulation.
Roof rafters 7 insultaion.
This roof type will require a breathable membrane like kingspan nilvent to be.
Insulating a pitched roof between and below the rafters is a very common roof insulation choice particularly for retrofit and refurbishment projects.
To create a warm pitched roof insulation such as kingspan kooltherm k7 pitched roof board should be fitted between and over the rafters.
The insulation is placed over the rafters and then a felt is placed on top.
If 180mm is to be installed then 100mm board might be introduced between the rafters there has to be a minimum 25mm air gap between the insulation and the underside of the tiles or slates with an 80mm board running.
For instance if the roof has 2 by 6 rafters and you want r 30 insulation which is standard in many communities you can add a 2 by 4 which will give you an 9 inch rafter space.
Utilising a pitched roof as a usable living space is an effective way to maximise the square meterage of a residential development.
You will be covered from head to toe in clothing and gear.
By installing high density 8 inch fiberglass batt insulation the rafters will then meet an r 30 roof insulation standard.
If you choose or need to go with an unvented roof you would need either exterior insulation or a flash coat of closed cell spray foam first then you could round out the insulation package with mineral wool.
Kingspan with a warm roof the usual process is to split the insulation into two layers.
The thickness of insulation will vary depending on the manufacturer s specification.
If you have an easy roof to vent and decide to go that route you could use mineral wool insulation between the rafters and beneath the vent channels.
In part 7 you ll learn how to insulate the attic rafters.
There will also be kooltherm k7 pitched roof board between the rafters image credit.
In part 6 of this series on attic insulation we dealt with proper attic ventilation and how it goes hand in hand with proper insulation.
Modern u value targets mean installing insulation between rafters only is rarely a viable option.
It allows insulation to be installed in a watertight roof either after the roof covering has been fixed on a new build or without disturbing an otherwise sound existing roof covering as part of a renovation.
The roof will typically be insulated above the rafter line creating what is most commonly known as a warm roof.
The battening and tiling is then fixed down over.