Chapter 1: Why are the clay tiles on our old Newbury house flaking and cracking?
What we find
Handmade clay tiles are fired at lower temperatures than modern ones and are more porous, so they take in water. When that water freezes it expands and pushes the face off the tile in thin flakes, a failure called delamination. You see it as orange or grey scales on the gutter, and a tile with a pitted, rough surface rather than a smooth one.
Older houses in the town centre also have tiles pegged or nailed to oak or softwood battens, and those fixings tire first. Moss compounds the damage by holding wet against the surface. If the tile has only lost its face, it may still hang and shed water for years; if it has split through, it will leak. Telling the two apart needs a close look, because a roof can look worse than it is.
What we fix
We go through the roof and replace only the tiles that are split or badly spalled, keeping every sound one. Matching replacements come from reclaimed stock or a maker who produces handmade plain tiles, chosen to suit the colour and curve of what is already there. Where the nails have failed, we re-fix the tiles with stainless or copper nails and replace soft battens in the area we have opened.
If the house is listed or in a conservation area, we use the same material and take photographs of the work for your records. Typical UK prices reported for a natural slate re-roof run from £120 to £180 per square metre, which gives a sense of the cost of traditional materials, though a clay re-cover is quoted separately from the survey. The pitched roofing service page describes each stage of a re-cover or patch repair, from stripping the affected area to checking the finished courses. On old houses in the centre of town, it is also worth asking us to look at the loft timbers while the tiles are off, since rafter ends and wall plates are easier to inspect then.