Roofing spans several measured items, and lumping them into one rate is where estimates go wrong. Price the roof structure and rafters, then felt and batten, then the covering — concrete interlocking tiles, natural slate, or a single-ply or felt flat roof — each per square metre. Add the linear items separately: ridge tiles bedded and pointed, lead flashings, and fascia, soffit and guttering.
Coverings vary enormously in labour and material: natural slate costs far more per m² than concrete tiles, and a complex cut roof takes more labour than a simple gable. Rooflights, valleys, verges and abutments are priced as their own items. A clear breakdown lets you flex the specification — swap slate for tile, add rooflights — without rebuilding the whole price.
ConstructQS includes roofing rates for structure, felt and batten, concrete tiles, natural slate, ridge, flashings, fascia and gutter, flat roofs and rooflights — per m² and per unit, in £ or €, all editable. Your own rates take priority and every line records where its price came from.