David Holmes, associate at AECOM, provides an overview of roofing costs
Choosing the right type of roof is more difficult than most people think. Roofs serve more than the practical purpose of protecting the building contents and occupiers from outside elements. They can help make it more energy efficient, bring in natural light and are important in defining the overall style of the property.
Gable roofs are some of the most popular types and are very easily recognised. They easily shed water and snow and can provide more attic space for storage or living, or be made into vaulted ceilings. Gable roof frames need to be constructed properly with adequate supports and can be covered with a variety of materials.
Flat roofs may appear to be totally flat, but in fact they have a slight pitch to allow for water run-off and drainage. Generally they are easier to construct than pitched roofs and require fewer materials. However, this initial low capital cost needs to be balanced with more expensive long term maintenance and repair costs.
Green roofs are aesthetically pleasing and are increasing in popularity. They are also energy efficient, thanks to all the vegetation which acts as an additional layer of insulation, and those cooling properties help combat the urban heat island effect. Layers are created using beneficial plant life, soil, drainage and waterproofing membrane. They do put a greater load on buildings than more traditional cold roofs (where the insulation is on the inside of the roof) or warm roofs (where the insulation is on top) so the designer needs to be aware of this.
The following rates are based on the UK average and represent typical prices at 2017 Q4. Please note that prices can vary significantly depending on the exact specification
Range £/m2
Includes insulation (U-value = 0.25W K) and vapour barriers as necessary; excludes decking
Single layer polymer roofing membrane; insulation £84-100
Single layer polymer roofing membrane; tapered insulation £150-180
Bitumen three-layer polymer modified bitumen system £87-120
Bitumen two-layer modified bitumen system £65-100
Bitumen felt roofing system, laid flat, with solar reflective paint finish £110-150
Mastic asphalt; applied flat; to concrete substrate £30-60
Single layer sheet roof; composite system; warm roof covering; vapour control layer; insulation and water proof membrane £85-120
Polymeric waterproof membrane; 1.2mm thick fleece backed membrane; cold roof £50-85
Roof walkways; 600mm x 600mm x 50mm precast concrete slabs on support system £49-65
Pitched roof: Tiles or slates
Includes reinforced underlay and battens as necessary; excludes roof structure
Natural Welsh slate tiles £120-160
Natural Spanish slate tiles £85-130
Synthetic slate tiles £70-90
Reconstituted stone slate tiles; random slates £68-90
Clay pantiles £42-55
Clay tiles; handmade; sand-faced plain tiles £85-130
Concrete tiles; interlocking; troughed / bold rolled £35-65
Concrete tiles; plain £34-53
Fibre cement slates £42-58
Red Cedar sawn shingles; preservative treated; uniform length £70-95
Pitched roof: Sheet metal
Includes breather membrane, underlay or vapour barrier as necessary; excludes roof structure
Copper sheet; mill finish; flat seam or wood rolled £170-205
Copper standing seam roof; mill finish £175-225
Extra for pre-patinated copper finish £40-70
Aluminium sheet; mill finish; wood roll; insulation (U-value = 0.25W K) £80-135
Aluminium sheet; standing seam; mill finish; insulation (U-value = 0.25W K) £80-140
Extra for Pvf2 aluminium finish £10-20
Stainless steel; terne coated sheet £140-170
Lead roof covering; code 7; welded seam; milled lead; laid flat £150-175
Lead roof covering; code 7; welded seam; milled lead, pitched roof £150-195
Zinc; Natural Bright Rheinzink; pitched £11-150
Extra for pre-weathered zinc £20-30
Pitched roof: Fibre-cement sheet
Excludes roof structure
Profile 6 fibre cement; single skin; natural grey finish £28-40
Insulated system (U-value = 0.25W K); Profile 6 fibre cement external skin; metal lining panel internally £55-70
Extra for coloured fibre cement £1.75-2.25
Double skin GRP translucent sheeting £60-73
Triple skin GRP translucent sheeting £67-81
Landscape roof
Excludes decking
Extensive sedum type flat roof; growing medium; waterproof layer; separation layer; low maintenance £220-280
Extensive rockery type green flat roof for planting with rockery type plants; growing medium; waterproof layer; separation layer; low maintenance £210-300