Roofing questions, answered

Roofing cost depends on the roof area and pitch, the material and its gauge, the structure carrying it, labour, accessories such as flashings and ridge caps, drainage, transport to site and the condition of any existing roof. A quotation is only meaningful once those are known, which is why we measure rather than quote a rate per square metre. See the roofing cost guide.

There is no single best material. The right choice depends on the roof design and pitch, what the structure can carry, the appearance you want, your maintenance expectations, the site’s exposure and the budget for the whole roof rather than the covering alone. See the material guide.

Metal sheeting is usually lighter and quicker to install, and a lighter covering needs less structure beneath it, so the installed cost of a metal roof is commonly lower than a tiled roof of the same area.

Repair generally suits isolated, identifiable faults on a roof that is otherwise sound. Replacement becomes the better option when deterioration is widespread, when leaks keep returning in new places, or when the structure or fixings can no longer hold the covering reliably. See repair versus replacement.

Most leaks start at a junction rather than in the middle of a sheet: flashings at walls and chimneys, ridges and hips, valleys, roof penetrations, sheet end laps and fixing points.

It depends on the roof area, the complexity of the shape, the system being installed, the crew size, site access and the weather. We give a programme with the quotation rather than a generic figure.

Ideally: the project location, the building type and stage, roof drawings or dimensions, the roof pitch and shape, whether an existing roof must be removed, your material preference, and photographs of the current roof and ceiling if this is a repair.

It depends on the size of the roof, which is not the same thing. Overhangs, pitch and roof shape all mean the roof surface is larger than the floor plan beneath it.

Floor area is the footprint of the building. Roof area is the actual surface of the sloping roof planes, including overhangs, so it is always larger than the footprint. See how quantities are worked out.

Often yes, where the damage is localised and the rest of the covering is sound. Check whether the profile, gauge and colour can still be matched.

In most cases gutters are worth planning with the roof rather than adding later. Without them, water runs off the edge onto walls, foundations and paving.

Waterproofing is the treatment applied where a roof holds water rather than sheds it — flat and low-pitch concrete slabs, parapets, box gutters, balconies and around penetrations.

Keep gutters, valleys and outlets clear; inspect after heavy storms; deal with coating damage and loose fixings before the next rains; avoid unnecessary foot traffic on the roof.

Yes. On new construction we work from the roof design and structural drawings, and we prefer to be involved before the structure is set out.

Commonly used options include corrugated and box-profile metal sheeting, long-span metal, stone-coated steel, clay tiles, concrete tiles and asphalt shingles. See the material guide.

The roof area used, the covering with its profile and gauge, structural work, fixings, flashings, ridge and hip caps, valleys, gutters and downpipes, fascia and soffit, labour, transport, removal and disposal, and the programme.

Compare how they assess the roof, not just their figure. Use our quotation preparation checklist: itemised quotation, labour and materials separated, accessories listed, structure considered, drainage addressed, process explained, warranties documented.