What Is a Roof Verge?

Verge, eaves and ridge

A roof has several edges, and each has its own name. The eaves are the bottom edge, where the roof meets the gutter. The ridge is the top, where two slopes meet. The verge is the sloping edge at the end of the roof, on a house with a gable. The verge is not on every roof: a fully hipped roof has no gable, so it has hips instead. Where there is a verge, it runs the full height of the slope and sees wind from the side as well as above.

How a verge is built

The last row of tiles at the edge is set to overhang the gable wall by a small distance, so water drips clear of the brickwork. Beneath the overhang sits the undercloak, a strip of board, plastic or a row of tile slips that supports the edge tiles and fills the gap. Traditionally the space between the tiles and the wall top is bedded with mortar and pointed, forming a visible band along the edge. Our answer on what verge undercloak is explains the support layer in detail. A bargeboard, a timber board fixed to the end of the roof, is sometimes used instead, with an overhanging gable.

The dry verge alternative

A dry verge swaps the mortar for cap pieces, usually plastic or composite, which are screwed or clipped to a fixing strip along the edge. Nothing is bonded, so nothing cracks in the same way. BS 5534:2014 expects verge components to be mechanically fixed, and mortar alone is not relied on, so many roofs are now finished with a dry system or with a bedded verge plus mechanical fixings. The types and fitting methods are set out in our dry verge systems guide.

What goes wrong at the verge

The verge is one of the most exposed parts of the roof, and its faults are well known. Mortar cracks and falls out in lumps, leaving the end of the tile battens open to rain. Edge tiles loosen, because the bed under them has crumbled. The undercloak rots or sags. The bargeboard behind may soften from damp. Dry caps can come off or rattle if their fixings fail. Our guides to verge repairs and why dry verge caps fall off go through the repairs in each case.

Why the verge matters

A failed verge lets wind-driven rain into the end of the roof, where it can reach the rafters, the wall top and the loft. Wind can also get beneath the edge tiles and lift them, which is how a storm strips a gable. Because the verge is at the edge of the house, a loose tile or cap that comes away in a gust can land on a path, so it is a safety issue as well as a weather one.

Measuring the overhang and the fall

The overhang matters more than it looks. Too little and rain runs down the face of the gable wall, staining it and soaking the brick. Too much and the unsupported tile edge can snap or lift in wind. The edge should also sit on a firm line, because a verge that dips or bows means the undercloak or the batten ends underneath have moved. Where a roof has been re-covered in a tile of a different thickness, the old verge detail sometimes no longer matches the new height, which leaves a gap that gets filled with mortar to hide it. That mortar is then the weak spot. A good survey looks at the line of the verge from the end of the street as well as from the ladder.

Planning and appearance

A verge shows from the street, so where a house is listed or sits inside a conservation area the council may take an interest in its appearance. Putting back what was there normally raises no issue, whereas swapping the material for something different may need consent, so ask the conservation officer at the council before you order anything or agree a date. Our answer on whether you need approval to fit dry verge gives the general rules.

What we do

We examine the verge from a safe working position, photograph the mortar, the edge tiles and the undercloak, and tell you if a repair will do. See the ridge and verge work page for the full range.