¶ Measuring roof insulation thickness
When measuring the depth of attic roof insulation, for example glass fibre/mineral wool quilt or blown insulation, take care not to compress the insulation during measurement. As stated in the DEAP Survey Guide “Ensure insulation depth is established by taking the average of a number of measurements (including insulation levels on attic hatches)."
In certain cases, it will be necessary to enter the roof sections separately in DEAP as per the DEAP Survey Guide: “Different U-values (e.g. significantly different depths or materials) must be treated as separate roofs in DEAP”1. For example, the attic space may be insulated in a piecemeal fashion with different thicknesses in different sections and areas:
For inaccessible sections of roof, the applicable default from Appendix S is applied if there is no other supporting evidence on the insulation type/thickness used. Where a default is applied to some sections and non-defaults to others, this is split into multiple roof sections in DEAP:
