What are the disadvantages of a pitched roof?

A sloping roof is the larger project of the two. For the same floor area it has more surface, more timber, more tiles and more days of labour, so replacement costs more. Checkatrade's October 2026 replacement guide gives a typical UK average of around £8,000, with hip roofs at £9,250 to £18,000 and flat roofs at £2,800 to £7,500, in a table headed as plus VAT. That gap is the first drawback most owners meet.

Scaffold widens it. The same guide gives £700 to £1,300 for scaffold, and a two-storey house with a sloping roof will almost always need a full lift of poles around the walls. A low flat extension, by contrast, can often be done from a tower. On any roof, check whether a quote includes VAT and scaffolding before you compare totals. Ours reaches you in writing after the survey as one sum, with its inclusions stated.

Height is a drawback in its own right. A steep slope is harder to inspect, harder to clean and harder to mend safely. Walking across tiles breaks them, so even a quick look usually becomes a job for someone with proper access, and that raises the cost of small repairs compared with a flat roof you can simply stand on.

It also hides trouble. A slipped tile, a loose ridge or a gap at the verge, which is where the slope finishes against a gable wall, can sit for months because nobody can see it from the garden. Binoculars on a calm day, and another look after each gale, catches a good deal of it. Gutters and fascias at the eaves are just as awkward to reach, so they tend to be neglected too. We keep off the tiles ourselves where we can, and you should too, because a boot on a tile can crack it without any sign until the next downpour.

A tiled slope is a few hundred separate pieces working together. Every tile hangs from a nail or clip on a batten, the thin timber strip the tiles rest against, over an underlay, the membrane that catches whatever blows past. Any link in that chain can fail. The lines that take the most punishment are the ridge, the hips, the valleys (the internal angles where slopes join) and the verges. Add chimneys and wall abutments, and you have leadwork that is dressed by hand and has to be checked at every visit.

Fixing is what separates a roof that stays put from one that sheds tiles. Since BS 5534 was revised in 2014, mortar alone is no longer trusted with ridge and hip tiles, which get a mechanical fixing too. Wienerberger, a tile maker, wants at least one mechanical fixing on every single-lap tile. A roof laid before that change may have neither, which is the point of our page on tile fixing to BS 5534.

Wind lifts a sloping roof as well as pushing on it. Marley warns that below 30 degrees the windward side can see strong suction, which pulls at tiles from above. Gales off the sea make that worth planning for on this coast, and a roof with the right fixings for its angle and exposure copes well. One without them is where slipped tiles begin.

Then there is the space under the tiles. A pitched roof creates a roof space, and that space needs air moving through it so damp can escape. For one kind of underlay Marley asks for a 25 mm gap along the eaves on slopes of 15 degrees or less, and 10 mm on steeper ones. Block those gaps, or lay insulation hard against them, and condensation can collect on the rafters. Eaves vents and loft hatches are easy to cover up when insulation is added later, and nobody notices until the timber turns damp. Our guide to underlay and ventilation covers the detail.

Against all that, the shape earns its keep. Water drains away down a slope rather than sitting on it, so there is no ponding and no dependence on a single membrane. Good clay and concrete tiles last for decades: Marley expects concrete to last around 60 years, while stressing that it promises nothing about any single roof. A well-aired loft keeps the timbers dry, which helps the whole structure last. A loft also gives you storage, depth for insulation and room for tanks and pipework.

So the real question is rarely which roof is better in general. A flat roof suits an extension or garage where a slope will not fit, and a pitched roof suits most main houses. If yours is tired and you are weighing a patch against a new covering, read our answer on repairing or replacing a tiled roof. Our pitched roofing hub lists the jobs we take on, from a handful of tiles to a full strip and re-lay.