Pitched roof tiling is the layered covering on a sloped roof: tiles or slates fixed to timber battens over a breathable underlay, with shaped ridge tiles closing the apex. The covering sheds rain; the layers beneath it manage wind, condensation and any water that gets past. On most UK homes the slope is what makes the system work, so the angle of the roof, the materials chosen and the way they are fixed all matter together.
What makes a roof "pitched"?
A pitched roof is one that slopes, usually with two sides meeting at a ridge along the top. The pitch is the angle of that slope, measured in degrees. Anything roughly above 10 degrees is generally treated as pitched; below that it behaves more like a flat roof and needs a different waterproofing approach.
The pitch is not just a style choice. It dictates which coverings are suitable, because every tile and slate has a minimum pitch below which it will let water track underneath. Plain clay tiles, for example, typically need a steeper slope than large interlocking concrete tiles. Steeper roofs shed water faster and cope better with driving rain, while shallower pitches rely more heavily on the underlay below.
The main parts of a pitched roof are worth naming in plain terms:
- Ridge — the horizontal line at the top where two slopes meet.
- Hip — an external sloping angle where two roof faces join.
- Valley — an internal angle where two slopes meet and channel water away.
- Eaves — the lowest edge, usually over the gutter.
- Verge — the sloping edge at a gable end.
Clay, concrete or natural slate for a Bedfordshire home
Pitched roof tiling is the layered covering on a sloped roof: tiles or slates fixed to timber battens over a breathable underlay, with shaped ridge tiles closing the apex.
There is no single best covering; the right choice depends on the existing roof, the look you want and the budget. Clay tiles, concrete tiles and natural slate are the three common options on local homes, and each behaves differently.
Clay tiles are made from fired clay and have been used on English roofs for centuries. They hold their colour well because the colour runs through the material rather than sitting on the surface. They suit older and period properties, and plain clay tiles in particular give the small, traditional appearance seen on many established streets. Clay generally costs more than concrete and needs a reasonably steep pitch, but it is durable and ages gracefully.
Concrete tiles are moulded from a sand-and-cement mix and are the most common covering on post-war and modern housing. They are usually cheaper than clay and slate, and large interlocking patterns cover a roof quickly with fewer tiles. The trade-off is weight — concrete is heavier than clay or slate, so the roof structure has to carry the load — and the surface colour can fade over the years. They work well on a wide range of pitches and are a practical match for many estate-built homes in the county.
Natural slate is a quarried stone split into thin sheets. It is prized for a clean, flat, fine-edged finish and a very long lifespan, often outlasting the fixings holding it in place. Slate is among the more expensive options and demands skilled fixing, but it is lightweight relative to concrete and gives a roof a crisp, understated appearance. Some homes use slate-effect concrete or fibre-cement tiles as a lower-cost alternative, though these do not carry the same character or longevity as the real stone.
A few practical considerations help narrow the choice:
- Match the existing roof if you are repairing or extending, so the new work blends rather than patches.
- Check the structure — swapping a lightweight slate roof for heavy concrete may need the roof timbers assessed first.
- Consider planning — in conservation areas or on listed buildings, the covering material can be restricted, and natural slate or specific clay tiles may be required.
- Think long term — a cheaper covering that needs replacing sooner can cost more over the life of the building than a dearer, longer-lasting one.
Battens, underlay and the layers beneath the tiles
What you see on a pitched roof is only the outer skin. Beneath it sits a system designed to keep the structure dry and ventilated, and these hidden layers do much of the real work.
The underlay is a sheet laid across the rafters before the tiles go on. It forms a secondary barrier: if wind drives rain under a tile or one cracks, the underlay channels that water down to the gutter rather than into the loft. Modern breathable membranes also let water vapour escape from inside the roof, which helps reduce condensation. Older felt underlays do not breathe in the same way, so roofs using them often rely on separate vents at the eaves and ridge to move air through the loft space.
Battens are the horizontal timber strips fixed across the rafters, over the underlay. Tiles and slates hang from or are nailed to these battens, and the spacing — the "gauge" — is set to match the covering so each course overlaps the one below by the correct amount. Battens should be of a graded, treated timber suitable for roofing; undersized or untreated battens are a common weak point in poorly built roofs.
At the top, ridge tiles cap the join between the two slopes. Traditionally these were bedded in mortar, but dry-fix systems are now widely used, holding the ridge tiles down mechanically with clips and screws and allowing ventilation along the ridge. Dry-fix avoids the cracking and loosening that can affect mortar over time, which is why it appears on much new and re-roofed work.
Taken together, the order from inside out is: rafters, underlay, battens, then the tiles or slates, with ridge tiles, hips, valleys and flashings sealing the joints. A covering can look sound from the ground while the layers beneath have failed, so when assessing a roof it is worth asking about the age and type of the underlay and the condition of the battens, not just the tiles. A surveyor or roofer inspecting the loft can usually report on these hidden layers far more reliably than a view from the pavement.
Reviewed: June 2026