Huts · Catalonia
Closing the roof of a barraca over two cold weekends
Of everything built without mortar in the Catalan countryside, the huts are what first stopped me on the path, and they are still what I find hardest to believe. This spring I helped close the roof of one, and this is the record of how a stone room is roofed in stone.
Laid 31 May 2026Checked again 18 September 20268 min on the hill
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Huts in the vineyards
The barraques that stand in the old vineyard districts inland from Barcelona were built as shelters for people working the vines: a place to wait out a storm, eat at midday, keep tools and sometimes sleep during the harvest. Most are small, round or roughly square outside and round inside, with a single low doorway and walls a metre or more thick. The remarkable thing is the roof. There is no timber in it at all. It is built of stone, each ring laid slightly further in than the one below until the rings meet at the top, a method that gives something like a dome without being a true arch.
The hut in this entry stood at the edge of a terrace in a district of rolling hills and old vines, and its roof had partly fallen in years ago, leaving a ragged hole where the top rings had been. The walls were sound. One of the groups I work with had spent the autumn clearing the fallen stone out of the interior and sorting it, and in March they began rebuilding the roof over two weekends. I was there for both, and spent most of them on a scaffold board inside the hut, passing stones up and learning.
Lift 2 of 4
Corbelling, ring by ring
The principle of corbelling is that each stone sits mostly on the wall below it and projects only a little inwards, with its tail held down by the weight of stone and earth behind it. As long as the tail is heavier and longer than the overhang, the stone cannot tip into the room. Each ring is laid all the way round before the next is started, so that the pressure stays even, and each ring projects a hand's width or less beyond the ring below. The roof narrows slowly, and the rings get smaller and flatter until the opening at the top is small enough to be covered by one large flat stone.
What the drawings never show is how much stone goes on the outside. For every stone that reaches inward to form the ceiling there is a mass of rubble and earth heaped on its tail outside, weighting it down, and the finished hut is really a dome of corbelled stone buried in a mound. On the first weekend we laid four rings, and three of us spent as much time outside, carrying buckets of rubble to the back of each ring, as the section leader and I spent inside, placing the stones that would show.
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The capstone and the moment the hut stood on its own
By the Sunday of the second weekend the opening at the top was about forty centimetres across, and the question was the capstone. The group had kept one aside since the autumn, a slab of limestone a little under a metre long and heavy enough that four of us were needed to lift it onto the top of the mound. It was walked up a ramp of planks, turned twice to find the side that sat without rocking, and lowered into place over the opening. Small stones were packed around its edges to lock it, and then earth was heaped over the whole top of the mound and trodden down.
Then the section leader went inside, looked up at the ceiling for a long while without saying anything, and asked for the props to be removed. The two wooden props that had stood under the top rings came out one at a time. Nothing moved. We all went in, as many as would fit, and looked up at a stone room roofed in stone, and I found I had nothing useful to say. In Scotland I have built plenty of wall, but never a ceiling, and it is a different feeling entirely to stand under your own work.
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What I would like to learn next
I learned more about stone in those two weekends than in the previous year of terraces. Corbelling punishes an ill-chosen stone immediately, because a stone that does not sit flat on the ring below rocks, and a rocking stone in a ceiling is not something anyone will leave. I also learned how different the Catalan and Scottish traditions are in the one respect I had never considered. The Scottish walls I know stand in the open and shed water from both faces. These huts are built to be buried, and their strength comes from what is heaped on top of them.
There are hundreds of these huts across the old vineyard districts, many of them slowly losing their tops as the earth washes away and the capstones slip. The group plans to work on another in the autumn, a larger one with a square outline and a round interior, where the transition from square walls to round roof is done with large stones across the corners. I have asked to be inside again. Whether I am allowed near those corner stones will depend on how carefully I have been paying attention.
Measurements in this note were taken with a folding rule and a level on the day and copied up the same evening. It is a hobbyist's record, not a specification, and any wall that holds up a path or a field deserves a proper builder.