The short answer
One slope or one hip at a time. Slipped or cracked tiles are replaced with matching ones, hip and ridge caps are refixed mechanically, and valleys and flashings are renewed where they have failed. A complete re-tile is only needed when the battens, tiles and underlay have all reached the end of their lives together.
A hipped roof has no gable ends. Every side slopes, and the sloping joints between the faces are called hips. Each hip is a long, exposed line of tiles that must shed water and resist wind, and the point where hips meet the ridge, the horizontal line along the top, is a busy junction with several tiles cut to fit.
Q1.1What goes wrong on a hip?
The capping tiles that sit along a hip were once bedded in mortar and little else. As that mortar crumbles, caps work loose and slide. Below them, the tiles on each face have to be cut to follow the angle, and those cuts are often where cracks start. We check the hips from the ground with binoculars where we can and from a ladder or scaffold where we must.
Q1.2Can a hip be renewed without a full re-tile?
When only a few tiles have failed, we replace them and leave the rest. If the hips have given up, we lift the caps, clean out the old bed and set them again with clips or screws alongside new mortar, the way current practice expects. Valleys, the internal gutters where two slopes meet, may need new lead or a new liner. Flashing means the lead or similar metal strip dressed into the joint between a sloping roof and a chimney or upstanding wall. When one fails, brown marks on a bedroom ceiling are a frequent result.
Q1.3When is a full re-tile the answer?
A full re-tile suits a roof whose battens have softened and whose underlay has perished along with the tiles. Our pitched roofing page explains how we decide, and our written quote, sent after the survey, spells out which of those routes suits your roof.