The roof insulation thickness will vary dependent on the required u value.
Warm pitched roof insulation thickness.
Kingspan with a warm roof the usual process is to split the insulation into two layers.
However warm moist air by its very nature will always find the passage of least resistance so the use of roof membranes and ventilation will effectively manage the small.
The idea behind a vapour control layer is to install it on the room side of the insulation so it blocks the passage of warm moist air rising into the pitched roof structure.
This will help to avoid your roof space becoming.
Ventilation is required for these roofs.
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.
It is possible to achieve very high levels of insulation in pitched roofs where the insulation is positioned at ceiling level because the insulation thickness is largely unrestricted by construction considerations.
A major factor influencing the design of pitched roofs with insulation at ceiling level is the type of roof tile underlay chosen.
A range of high performance insulation products for a variety of pitched roofs including loft insulation between and over rafters and pitched roof sarking.
The best way to insulate a pitched roof is by installing insulation between and above the rafters.
Warm deck the insulation is placed over the rafters and then a felt is placed on top.
There is a requirement when refurbishing a roof to have a minimum u value of 0 18 w m k in england and wales but for a complete re roof in wales the minimum u value required is 0 15 w m k.
Level for a cold pitched roof or at rafter level if a living area within a warm roof construction is desired.
Our u value calculator is free and simple to use for calculating u values specific to your roof construction design.
As there s no insulation below rafters headroom is maximised creating more useable space.
For a warm roof solution you will need to install insulation in the plane of the roof pitch that is immediately below the sloping roof.
There will also be kooltherm k7 pitched roof board between the rafters image credit.
Introduction warm cold roofs this guidance offers guidance on the difference benefits between warm and cold roofs.
The battening and tiling is then fixed down over.
Cold deck roof a cold deck roof is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a pitch roof.
This approach can be used to create an unventilated roof structure helping to keep out unwanted drafts.
The thickness of insulation will vary depending on the manufacturer s specification.
