Two figures decide what a re roof costs: how big the roof is and what goes back on it. This guide crosses the two so you can find your own house on the table.
Work out your roof area first
Roof area is not floor area. On a typical 35 degree pitch, roof area is roughly 1.2 times the footprint of the part of the house it covers, then doubled because there are two slopes. A 5 metre by 8 metre footprint gives a roof of around 96 square metres, not 40.
As rough guides we use: mid terrace 55 to 75 square metres, semi detached 70 to 100, small detached 100 to 140, larger detached 140 to 200 and beyond. A bungalow of the same footprint has a bigger roof relative to its floor area, which is why bungalow re roofs surprise people.
Cost by covering, per square metre
Concrete interlocking tile is the value option at roughly 95 to 130 pounds per square metre installed. Clay plain tile and clay pantile run 130 to 170. Natural Welsh or Spanish slate sits at 170 to 220. Cotswold stone slate is a different category again because of the weight, the reclaimed material and the labour in setting out diminishing courses.
Those rates include strip, disposal, new treated battens, breathable membrane, new lead work at the standard details, ridge and verge, and scaffolding. They do not include structural timber replacement, chimney rebuilds, dormer work or roof window changes.
Crossing size against covering
Mid terrace in concrete tile lands around 5,500 to 8,500 pounds, and in natural slate around 10,000 to 15,000. Semi detached in concrete tile is roughly 6,500 to 12,000, in clay 9,000 to 15,500, in slate 12,000 to 20,000.
Detached properties vary too widely for a single figure, but 100 to 140 square metres in clay tile typically sits at 13,000 to 22,000 pounds. Heritage stone slate on a Cotswold property regularly exceeds all of these, and the roof will still be there in a hundred years.
Complexity is the third variable nobody quotes for
A plain gable roof is the cheapest shape to cover because every course runs from verge to verge. Hips need cutting on both sides of every course. Valleys need lining and both slopes cut to them. Dormers need four separate junctions each.
As a rule of thumb, add ten per cent for a hipped roof, and another ten to fifteen for a roof with two or more valleys or dormers. This is why the neighbour's identical looking house came in cheaper.
Where the money can sensibly be saved
Doing the whole roof at once rather than a slope at a time saves the second scaffold and the second setup. Bundling fascia, soffit and gutter renewal into the same scaffold period saves most of the access cost on that work.
Choosing a good concrete tile over a mid range clay saves thousands and, on a post war estate house where the neighbours all have concrete anyway, costs you nothing in appearance or value. On a stone or clay street, the reverse is true and the cheap covering will cost you at sale.
How much does it cost to re roof a terraced house?
Typically 5,500 to 8,500 pounds in concrete tile and 10,000 to 15,000 in natural slate. Access from the front only, and shared party walls, both affect the figure on a terrace more than on a detached house.
Is a bungalow cheaper to re roof than a house?
Not per square metre, and often not overall, because a bungalow has a larger roof relative to its floor area. Scaffolding is cheaper and quicker on a single storey, which offsets some of it.
How much extra does a hipped roof cost?
Roughly ten per cent over a plain gable of the same area, because every course has to be cut to the hip on both sides and the hip itself needs bedding or a dry system.
Can I keep my existing tiles and just replace the battens and felt?
Sometimes, with clay or slate that is still sound. Expect to lose ten to twenty per cent to breakage during stripping, so budget for replacements. It rarely works with old concrete tiles because they are usually at the end of their life anyway.
Does a new roof add value to a house?
It rarely adds its full cost in value, but a visibly failing roof reduces offers by far more than the repair would cost, and it is one of the first things a surveyor flags.
Evans Roofing & Maintenance Ltd, Witney, Oxfordshire. Call 07960 482233 for a free written quote.