Reroof thermal insulation layer

[PaulDMW]

Hi everyone,

Looking for some help please.
I'm having a full reroof on my 1930's end terrace in the next few weeks. It's slate with torching and moving to tile with a breathable membrane. What do I need for insulation/building control? There's double loft floor insulation at the moment but nothing between the rafters. I can't find much on the forum.

 

[PaulDMW]

Building regulations: Re-roofing - Roof - Planning Portal

Details of the planning permission and building regulation regimes for Roof in England

www.planningportal.co.uk

Energy Efficiency​

As a roof is defined as a thermal element, the work to re-cover a roof should also include for improving the thermal insulation properties of the roof.

STANDARDS FOR NEW THERMAL ELEMENTS W/m2 k Element (1) Standards.
Gable Wall 0.28 W/m2.K(2)
Pitched roof – insulation at rafter level 0.18 W/m2.K

 

[PaulDMW]

But as the roof is a cold roof at the moment, it is not a thermal element(contradicting the Planning Portal information above ) I just need:

• i.e. re-roof covering, if possible 280mm of glass fibre insulation over the ceilings, with adequate roof void ventilation

 

[Alastairreid]

The insulation is at rafter level, as long as that is up to spec you don't have to do anything.