A house roof is usually an internal timber structure, clad with tiles. The structure is supported off the external walls. In certain circumstances, the timber structure will shift outwards at the top of these walls, albeit slowly. This, in turn will cause sagging of the roof slopes and the ridge of the roof. Causes of such distortion include inadequacy of the supporting timber roof structure and replacement of the original tiles with heavier, concrete tiles. Our engineers can inspect the internal roof structure and assess its suitability to support the weight of the tiles and solar panels, if fitted.