The short answer
A gable roof is a pitched roof with two sloping sides that meet along a central ridge, leaving a triangular wall, the gable, at each end of the building. It is the simplest pitched design, with few junctions and an easy build. Rain runs off the two long sides, and the sloping edge at each gable end is called the verge. Gable roofs are common across the UK on houses of every age.
The shape and its parts
Picture the outline of a child's drawing of a house: a rectangle with a triangle on top. The two slopes of the triangle are the roof planes, and the line where they meet is the ridge. The triangular wall under each end is the gable, which can be brick, stone, render or timber cladding. The sloping edge of the roof at the gable is the verge, where the tiles finish.
Inside, the roof is carried by rafters or trusses spanning from the wall plates up to the ridge. The long bottom edges are the eaves. A gable roof has only one ridge and no hips, so there are far fewer awkward junctions than on more complex shapes. Our answer on what a hipped roof is sets out the contrast.
Why it is so common
The gable roof is cheap to build, quick to cover and easy to repair. Water runs off the two slopes in simple lines. The loft below is a regular shape, so it suits conversion, and there is room for windows in the gable wall. On terraces and semi-detached houses it often sits side-on to the street, and a gable end faces the road on many 1930s and later houses.
For solar panels, a gable roof offers two clean planes, and one often faces south or close to it. That makes it a practical choice for panels.
The weak points
The verge is where most problems start. It is the exposed edge of the roof, and wind can lift tiles there. Traditionally the verge was sealed with mortar, which cracks and falls out in time. Modern practice uses mechanical fixings and dry-verge systems, as BS 5534 expects. Our guide to dry verge systems explains how they work.
The ridge is another point. Mortar bedding on the ridge tiles cracks, and ridge tiles can loosen. Gable walls are tall and exposed, and the pointing and the barge board or fascia at the top need checking. A gable roof also has a large flat wall that catches driving rain.
Gable roofs through the decades
The gable roof has been built in almost every period. Medieval and Tudor cottages carried steep gables covered in thatch or stone slate. Georgian and Victorian terraces often turned the gable to the street, with a parapet to hide it. Interwar semi-detached houses frequently show a front-facing gable above a bay window, and many post-war and modern estate homes use a simple gable roof because it is quick to put up with prefabricated trusses.
The covering varies with the era, from handmade clay plain tiles on older homes to concrete interlocking tiles on newer ones. That affects what the verge looks like and how it is fixed, so an older gable roof may need a different approach to repair than a new one.
Gable walls and the roof together
A tall gable wall must be tied to the roof structure so it does not move in the wind. Straps from the wall to the rafters or ceiling joists do this, and a gable wall with bulging brickwork or open joints needs a structural opinion. The coping, or the finish at the top, should shed water away from the wall, and failure there lets damp into the loft end.
Wind and exposure
A gable end acts like a sail in a gale. Strong wind hits the flat wall and the verge, and it can lift tiles along the edge. Wind also rushes over the ridge, creating suction on the leeward slope. The sensible approach is good fixing at the verge and ridge, and a solid gable wall properly tied to the roof.
Some gable roofs are built with a gable overhang, called a bargeboard or a cantilevered verge, which adds to the wind catch. If you are installing a loft conversion with a gable window, the structure at that wall needs to be strong enough.
Loft conversions in a gable roof
A gable roof is the easiest shape to convert, because the loft is a full rectangle and the gable wall takes a window. Check the roof timbers are strong enough for floor loads, and that the stairs have headroom.
Repairs and survey
When we survey a gable roof, we look at the verge tiles, the ridge, the pointing at the gable and the condition of the wall. We photograph what we find and tell you what needs doing, and what can wait. A loose verge tile or a cracked ridge is a typical repair. For the wider range of our tiled-roof work, see our pitched roofing page.
Every roof is different. A free survey with photos settles it for yours.
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