What Is a Dry Hip System?

Some houses have a roof that slopes on all four sides, which is what makes it a hipped roof. Where two sloping sides meet at an outward corner, a line of hip tiles runs diagonally from the high point of the roof to the eaves, the lower edge over the gutter. The tiles cap the join and shed water to either side. Traditionally each hip tile was bedded in mortar, with a metal hip iron screwed at the foot to stop the whole row creeping downhill.

How does a dry hip hold the tiles on?

The dry version replaces the mortar with a fixing system. A starter piece at the eaves end takes the first tile. A batten or bracket runs up the hip to carry the rest, each tile clipped or screwed to it. At the top, a hip union, a shaped plastic or metal piece, joins the hip to the ridge, and a cap closes the bottom. The tile joints are dry and open to movement without cracking.

A dry hip fits best where the old mortar line keeps failing. Hips take a lot of weather, because they stand proud on the corners of the house and the wind hits them from two directions at once. Mortar there cracks, falls out and lets tiles slip down the slope. Mechanical fixing deals with the cause, not just the symptom.

Does a dry hip suit every hipped roof?

Not quite every one. It needs a tile for which the maker supplies a hip kit, and the pitch must be one the kit can handle. Marley says that BS 5534, the slating and tiling code of practice, led to bedded ridge and hip tiles needing mechanical fixings, so a fixed system is the safe route on many roofs. Odd shapes need care: a hip that meets a valley, a bay window roof or a steep-pitched turret may have several angles in one run, and standard unions do not cover those.

On a slate roof with lead-covered hips, a dry system is a different question, because the hip covering there is part of the slate detail and the right answer comes from the survey.

The principle is shared with a dry ridge, but the geometry is not. A ridge runs level, so the tiles sit squarely on the board and the weight is carried evenly. A hip slopes, so every tile wants to slide downhill, and the fixing has to resist that pull as well as the wind. That is why the foot of a hip needs a firm anchor, either a starter piece screwed to the timber or a hip iron designed for the system.

Why do hip tiles slip when they are fixed badly?

Because they are on a slope, and a loose tile moves a little with each gust. Over a winter that movement cracks any remaining mortar and works the fixings out of their holes. The top of the hip is the second weak point. Where the hip tiles meet the ridge, three lines of tile come together, and the union has to be a good fit or the joint lets in rain. Our page on hip tile repair covers the fault side, and what is dry ridge explains the ridge version.

A quote for hip work should name the system, not just say dry-fix. Ask which maker's kit goes on, and whether the kit has been tested to BS 8612, the dry-fix standard. Ask how the foot of the hip is anchored, what is fixed to the timber and whether the old hip batten is being reused. Finally, ask what happens to the hip where it meets the ridge, because that junction needs the right piece for your tile.

Will a dry hip look different from the old one?

If the tiles are the same, the line looks similar from the street, though the joints between tiles tend to be tidier. If the old hips were a different shape, a conservation area or a listed building may restrict what can change, so check with Somerset Council's planning team first.

We survey the hips from the roof itself, show you photos of each junction, and send one written price afterwards. For the whole system, read the dry ridge and verge page. A photo of each hip taken from the garden is a useful first step.