How Much Does a Lead Roof Cost per m2?

Cost guides for flat roofs usually quote a rate per square metre for felt, rubber or fibreglass, and they can because those coverings are laid in much the same way from one roof to the next. Lead is different. It is a heavy metal, shaped by hand, and a small bay window top and a large flat roof use the same metal in very different ways.

On a small roof, the joints, the upstands and the edge details take far more time than the flat sheet in the middle, so the cost per m² climbs as the area falls. On a large plain roof the reverse is true. A rate per m² for one will mislead you on the other. A plain, shallow roof with easy ladder access sits at the cheaper end of whatever the market charges, and a cut-up roof full of upstands and rolls sits at the other.

That is why we do not put a pound figure on a lead roof before looking. The useful answer is a list of what sets the price, and a promise that the written quote, once the roof is measured and photographed, is one total. Crown's own guide prices cover the other trades; lead roofs are quoted on survey. A per m² price quoted down the phone with nobody on the roof is a guess.

Lead is sold by code, and each code is a thickness and a weight per square metre. Royston Lead's brochure gives Code 5 as 2.24 mm and 25.40 kg per m², Code 6 as 2.65 mm and 30.05 kg per m², Code 7 as 3.15 mm and 35.72 kg per m², and Code 8 as 3.55 mm and 40.26 kg per m². Between Code 5 and Code 8 there are almost 15 kg of extra metal in every square metre, and that shows in the price of the material.

The brochure lists Codes 5 to 8 for parapet and box gutters and tapered valleys, and Codes 7 and 8 for pitched valley gutters among other uses. A flat roof or a bay top is a matter of choice between them, shaped by the span, the foot traffic expected and what the existing roof carries. A heavier roof also needs the deck underneath to take the load.

Our guide to lead sheet codes sets out the full range. Ask any quote to name the code, so you can see what you are being offered.

A lead roof is laid in bays, each with its own drip or roll, and the number depends on the size and fall of the roof. Our page on drips and rolls explains why. More bays mean more timber and more labour, which is a reason two roofs of the same area can be priced differently.

Then comes the deck. If the boards beneath are sound, the lead goes straight on. If they are rotten or uneven, they have to be renewed first, and the survey is where that is found. Insulation, falls built into the deck and the edges and upstands all belong in the picture too.

Access is the largest swing factor. A bay window top at ground level needs a ladder. A flat roof on a second storey needs a tower or scaffold, and Checkatrade's September 2026 fascia and soffit table puts scaffold at £300 to £600 per elevation per week. Check whether the total you are offered has VAT and scaffold in it.

A lead bay top is covered on our page for lead bay window roofs.

For comparison, Checkatrade's September 2026 guides give felt at £50 to £80 per m² and EPDM rubber at £80 to £100 per m², with fully insulated GRP at around £210 per m². Those are other coverings, and they are a reference for the sort of numbers that flat roofing runs to, not a rate for lead. Lead is priced by its weight and its detail, and the survey is what turns that into a number.

Building rules can enter the picture as well. Under Approved Document L, fitting fresh waterproofing to a flat roof is renovation work, and insulation upgrades may be required with it. Ask your building control body what applies to your roof; we would raise it at the survey.

We look before we price. You get photos of the roof, the deck and the edges, then one written total price. Send the rough size of the roof, what covers it now and whether it leaks, and the survey measures the rest. The main lead work page covers the wider service.