Slate, pantile or concrete tile, compared by the people who fit all three

Natural Welsh slate is the covering most of York's Victorian and Georgian streets were built with, and it is still the benchmark. It splits thin, lays crisp and holds its colour for a century. A slate roof fitted properly will outlive the person paying for it.

For period homes we prefer reclaimed slate, weathered stock that matches the neighbouring rooflines rather than sitting beside them looking new. New Welsh slate from the Penrhyn and Ffestiniog quarries is the alternative where a whole roof is being recovered. Spanish slate costs less, but quality varies wildly between batches, so we grade every pallet before it goes up.

Slate is also lighter than most people expect, around 25 to 30 kilograms per square metre against 40 to 50 for concrete tile. The structural question almost always runs the other way, it is concrete going onto an old slate roof that overloads timbers, not slate going back on.

The S-shaped clay pantile is the other half of York's roofscape, the rolling orange-red roofs on terraces, cottages and farmhouses across the Vale of York. Fired clay keeps its colour for life, where concrete fades in a couple of decades, and a clay pantile roof runs 60 years or more.

Pantiles are single-lap and lighter on battens than plain tiles, but they are less forgiving of poor workmanship, the side laps and verge details have to be right or wind-driven rain finds its way in. Matching matters too. A 1930s pantile has a different profile to a modern one, so for repairs we source reclaimed pantiles that sit flush with the originals.

In York's conservation areas, like-for-like clay is usually a condition of consent on visible slopes. Swapping a clay roofline for concrete is the single most common way a period terrace loses its face.

Concrete roof tiles cover most of the homes built around York from the 1960s on, and for those estates they remain the sensible choice. They are the cheapest covering to buy and to fit, they are made to consistent modern dimensions, and a concrete tile reroof gives 40 to 60 years of service.

The honest trade-offs are weight and looks. At 40 to 50 kilograms per square metre concrete is the heaviest of the common coverings, so putting it on a roof built for slate needs the timbers checked and often strengthened. And the colour is in a surface coating, not the tile, so concrete fades and picks up moss in a way fired clay and slate never do.

Where concrete is the right answer, the value sits in the details, dry ridge and verge instead of mortar, proper ventilation, and new underlay and battens beneath, all standard on our reroofs.