Warm Pitched Roof Insulation Thickness

When specifying the insulation for the pitched roof it is important that the thickness of insulation used achieves the required u value.

Warm pitched roof insulation thickness.

The below table shows the thickness of insulation required for a typical warm roof construction with insulation fitted above the rafters. 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. 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. As there s no insulation below rafters headroom is maximised creating more useable space.

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. The thickness of insulation will vary depending on the manufacturer s specification. 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. A major factor influencing the design of pitched roofs with insulation at ceiling level is the type of roof tile underlay chosen.

This approach can be used to create an unventilated roof structure helping to keep out unwanted drafts. 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. There will also be kooltherm k7 pitched roof board between the rafters image credit. The battening and tiling is then fixed down over.

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. Cold deck the insulation can be placed between the rafters or it can be placed between the ceiling joists. A range of high performance insulation products for a variety of pitched roofs including loft insulation between and over rafters and pitched roof sarking. Warm deck 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. Kingspan with a warm roof the usual process is to split the insulation into two layers. The roof insulation thickness will vary dependent on the required u value. Ventilation is required for these roofs.

Level for a cold pitched roof or at rafter level if a living area within a warm roof construction is desired. This will help to avoid your roof space becoming.