Tools · Catalonia
Batter frames, string lines and the argument about slope
I brought a batter frame to a Catalan repair day in my second winter, and it caused more conversation than anything else I have ever carried up a hill. This entry is about that frame, the string lines that go with it, and what happened when a tool from one tradition met the eye of another.
Laid 25 January 2026Checked again 17 May 20267 min on the hill
Lift 1 of 4
What a batter frame is for
A batter frame is a template for the cross-section of a wall. For a Scottish double dyke it is usually made of four lengths of timber screwed into an A-shape with a flat top, the width of the base at the bottom, the width under the cope at the top, and the height of the finished wall. One frame is set up at each end of the length being built, plumbed so it stands upright, and string lines are run between them along each face at the height of the course being laid. The waller builds to the string, raising it a course at a time as the wall climbs.
The frame I made in my flat in Barcelona followed the proportions I learned in Galloway, scaled to the walls I expected to meet: a base a little under eighty centimetres, a top of about thirty-five, and a height of a metre and a quarter. It is made of offcuts, it folds flat with two wing nuts, and it has been carried up more hills than any other object I own. On a field dyke it is the difference between a wall that looks built and one that looks piled.
Lift 2 of 4
Taking it to a terrace
A terrace wall needs only half a frame, one leg for the face and a post for the bank, since there is only one face to shape. I cut a second frame for this in the winter of 2023, set to the backward lean I had measured on terraces the year before. The first time I set it up on a repair day, two of the older volunteers stopped work to watch. One of them asked, with complete politeness, what it was for, since the wall was already there on both sides of the gap and the string could simply be run from one surviving end to the other.
He was right, and it took me an embarrassing length of time to see it. On a long repair the old wall on either side is the frame, and it is a better one than mine because it matches exactly the wall being mended. Where a frame earns its keep is on a new wall, or on a gap so long that the ends are out of sight of each other, or on a stretch where the surviving wall has itself moved and cannot be trusted. Those are rarer on terraces than on field dykes, and I have adjusted what I carry accordingly.
Lift 3 of 4
String lines and a dispute about the eye
The string lines are a different matter, and here the argument went the other way. Most of the Catalan volunteers I work with build to the eye, sighting along the face every few stones and correcting by feel. The best of them are astonishingly accurate. The newer volunteers, though, build to the eye too, and their sections are visibly wavier than the old walls on either side. On one repair day the section leader asked me to run a line for the newer people only, and by the end of the day two of them had asked for a line of their own.
The honest conclusion is that a line is a crutch for the inexperienced and a check for everyone else, and there is no shame in either. I have watched a Catalan builder with fifty years on the hillsides take a line I had run, glance along it, and move it a finger's width because the stone he was about to lay would sit better there. He was right about that too. The line tells you where the wall should be. The stone tells you where it can be, and a good builder listens to both.
Lift 4 of 4
Measuring four repairs
Last winter I started taking a small notebook and a folding rule to every repair and recording the batter of the surviving wall on each side of the gap. It is a crude measurement, done by holding a level against the face and measuring back to the stone at a fixed height, and it is taken on walls that have had a century or more to settle. Across four terraces in two districts the lean ranged from about one in four to one in seven, and the steepest walls were the lowest, which is roughly what the theory predicts.
The Scottish dykes I measured on a visit home were much more consistent, close to one in six on each face, which says more about how uniformly the old wallers there were trained than about the stone. What I have not managed is a pattern I could write down as a rule for terraces. The builders who made them read the slope, the stone and the soil and chose the lean on the spot, and I suspect the most useful thing my frame can do on a Catalan hillside is to record what they chose, not to tell anyone what to choose next.
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.