Whether you are re-roofing an existing house, building a new roof on an extension, or replacing a flat roof over a garage, the cost depends on the size of the roof area, the material chosen, the pitch and complexity of the roof shape, and whether any structural work to the timbers is needed before the new covering can be laid.

Full Roof Replacement Costs

For a typical three-bedroom semi-detached house with a standard duo-pitched roof of around 60 to 80 square metres of sloped surface, a full roof replacement stripping the existing covering and laying new concrete interlocking tiles on new battens and breathable underlay typically costs five thousand to nine thousand pounds. Clay tiles, which are more expensive than concrete, add one thousand to three thousand pounds to the material cost. Natural slate, if used to replace an original slate roof on an older property, is more expensive still, typically adding two thousand to five thousand pounds compared with concrete tiles.

Larger detached properties

A four to five-bedroom detached house with a roof area of 120 to 160 square metres costs eight thousand to sixteen thousand pounds for a standard concrete tile roof replacement, and more for premium materials.

What Is Included in a Roof Replacement

A professional roof replacement should include stripping the existing tiles or slates and disposing of them, inspecting and replacing any rotten or damaged rafters and battens, laying a breathable membrane underlay, fixing new treated battens, laying the new tiles or slates with appropriate fixings, re-bedding or replacing the ridge and any hip tiles in mortar or with dry-fix components, repointing or replacing any verge details, and cleaning out gutters on completion.

Flat Roof Replacement

Flat roofs over garages, extensions, and bay windows require periodic replacement when the covering reaches end of life. A standard felt flat roof replacement on a garage of around 20 square metres costs one thousand five hundred to three thousand pounds. A higher-quality EPDM rubber or GRP fibreglass system on the same area costs two thousand to four thousand pounds and provides a longer-lasting, lower-maintenance result.

Structural Timber Repairs

When a roof is stripped for replacement, structural issues with the underlying timbers sometimes become apparent: rotten rafters, failed purlins, undersized members, or inadequate support. Structural timber repairs can add one thousand to five thousand pounds to the project cost depending on extent. Factoring in a contingency for potential structural work when budgeting for a roof replacement reduces the risk of unexpected cost.

Summary

A full roof replacement on a typical three-bedroom house costs five thousand to nine thousand pounds for concrete tiles, and more for clay tiles or natural slate. Flat roof replacements on garages or extensions cost one thousand five hundred to four thousand pounds depending on size and material. Structural timber repairs discovered during stripping add to the total. Always obtain three detailed quotes specifying materials and guarantee provision before committing to a roofing contractor.