Why Slate, Clay Tile and Lead Fail in Different Ways

Two houses on the same street, built in the same decade, can need very different roof work. One loses a few tiles in every gale. The other develops a damp patch around the chimney. The difference is often the material, because each one fails in its own way.

Clay and Concrete Plain Tiles

Plain tiles are small and overlap in a regular pattern, which makes a roof forgiving and repairable one tile at a time. Clay can last for generations, yet it absorbs water over decades and may flake in frost. Concrete tiles are heavier, and their surface coating wears away, leaving them rougher and more prone to moss. Both depend on their fixings: nails corrode, clips loosen and tiles slip. Replacing single tiles is usually straightforward, although matching the colour of old clay can take some searching.

Mortar is the other weak point. Ridge and hip tiles are bedded in mortar or held by dry-fix systems, and when mortar cracks the tiles loosen and water can get underneath. Re-bedding a ridge is a common repair and is usually far cheaper than replacing the roof covering.

Natural Slate

Good slate is thin, light for its strength and long lasting, but what fails is usually the nail rather than the stone. Iron nails rust, and slates slide down one by one. Poor quality slate can split into layers. Repairs use copper or stainless steel fixings, or small clips that hold a slate in place without a nail. Slate is also brittle underfoot, so walking on it can crack more than it cures, which is another reason to leave inspection to people who do it daily.

Lead Work

Lead lines the awkward junctions: around chimneys, along valleys and where roofs meet walls. It expands and contracts with every change of temperature, so long unsupported sheets creep, buckle or split over the years, and lengths are normally kept short for that reason. When water appears near a chimney breast, damaged flashing is a common cause. Well fitted lead can last for decades, and small repairs are often possible without renewing the whole run. It is also worth checking whether the lead has been fixed with sealant alone; sealant dries out and splits, while properly dressed lead is held mechanically.

Flat Roofs

Torch-on felt is a bonded membrane laid in layers. It tends to fail at the seams, along the edges and wherever water pools, since standing water speeds up ageing. Sun can cause blisters, and cold snaps can crack the surface. A localised patch may be enough when the damage is limited, but a roof that is blistered all over usually needs to be laid again. Keep outlets and gutters clear so water drains away rather than sitting. Flat roofs deserve inspection more often than pitched ones, since problems show up quickly after heavy rain and ponding can often be spotted from an upstairs window.

Choosing Repairs That Respect the Material

Whatever your roof is made from, a good repair uses like-for-like materials wherever possible and respects the age of the building. When a problem does appear, a search for roof repair Fleet will bring up local firms, but it helps to ask whether they work regularly with your particular material, and to ask them to explain why each repair is needed and what would happen if you waited a year. A straight answer is a good sign. A contractor experienced with slate will handle fixings differently from one used to concrete tiles.

If a storm causes the damage, photograph everything before anything is moved, contact your insurer promptly and keep the paperwork. Clear records make any claim simpler, and they give the repairer a better picture of what happened. Knowing what your roof is made of is the first step to looking after it properly.