I got a call from my neighbour to say part of our dyke had collapsed into the road. They'd scooped up the debris to clear it.
The foundations had been undermined when a water main was installed about fifteen years ago. A bulge soon followed and it was a matter of time before it burst.
Rather than faff around chasing the water board, I thought I'd have a bash at rebuilding it.
It was a massive jigsaw puzzle with no regular parts and an unknown quantity of mortar. The dyke must be nearly three hundred years old, it's hollow and was home to thousands of snails, their shells filled the void.
I've got it back up to coping stone height, I'm keeping my fingers crossed that I've still got sufficient stone to complete it
The guys that built it back in the day were really skilled. Its made mostly from ill shaped whinstone with some field stones in the mix.
As an homage to those builders, I've strimmed back all the grass, thistles and brambles along its length. The first cut was the hardest, keeping it in check shouldn't take more than an hour or so every month in the growing season.
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You are a man of many talents McM. We knew you were good with wood (and paint), but stone's a little more tricky.
Good work.
Ah, thought this was going to be another Hebden Bridge style thread... 😉
Just stick your finger in it.
Whinstone is impervious so a wee bit trickier to build if mortar is too workable but it's fairly abundant in your area. Must have been a good day for the Firth of Forth to look so blue in the last pic and the Bass rock clearly visible on the horizon
Nice work! Down this way, it might have been a bit trickier, it's all dry-stone walling, no mortar to worry about, but fitting the stones together is a much more involved job!
Is it a wall surrounding a manse or some similar "big" house? It's unusual for a wall/dyke to use mortar (cost basically). I've done dry stone walling for many years first as maintenance on the farm then I did it as a job for a few years. Not easy figuring out how to fit things together if you aren't used to it.
Interesting. How long did it take you to get a feel for the stone and the way it fitted together?
Would a dry stone wall have slumped progressively when the water undermined it, but ultimately survived? It's not uncommon to see walls that highways authorities have built with a cemented cope, where the wall has collapsed leaving the cope bridging the gap.
Dry stone walls will "settle" to some extent if there's subsidence of some kind. Obviously there's a limit to how much settling can take place but it's much more than a rigid, inflexible mortared wall can handle.
From the OP's first shot it also looks like the ground away from the road is higher so the earth will be pushing the wall towards the road as well. When the wall does collapse, because of the mortar, it tends to be long sections that go rather than a short 'V' shape that you get with dry stone walls.
OP: your problem now is that your repaired section will outclass the original wall. It will gnaw at you begging you to rebuild it to the same standard 😉 😆
There's no chance of my work comparing with the original builders. Their work is flush mine has a bit of a Mexican wave to it.
The wall surrounds a house that later in life became a manse. Years ago I attended a lime harling course when I was restoring a croft up in Orkney. The guys explained that lime mortar was so costly that when an old building was demolished not only would it's stone be recycled but also the mortar.
The builders of my wall used the lime mortar very efficiently. There's no way the wall could be built along the lines of a dry stone dyke without it. Our stable block is built using the same whinstone but all the details around the doors, arches and windows are in faced sandstone. It's our understanding that the block was to have been lime rendered but the chap who commissioned it died before it was completed.
I've repaired smaller sections of the dyke before. This was much more tricky as the ground level in the field it contains is much higher than the road side. Trying to rebuild it upon the remains of the foundation was a leap of faith. You do get a feel for the stone. I've looked at how the original builders used their bigger stones to join both sides of the wall together. I'm going to point the recessed joints with some lime mortar, hopefully it will weather in quite quickly.
I got my coping stones up today. I'll need to give it a final pointing, but I'm relieved its back up again. Just the mortar debris to clear away.
There are other weak points in the dyke, I feel at least now I'm better equipped to deal with them
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Good job!
I've got some whin sill stone in my BBQ (along with snap granite, Icelandic vesicular basalt, Cornish granite and olivine from the Canary Islands) and joke that when it rains on the BBQ (inevitably) it's because I haven't taken the Whin Sill Factor into account (very bad geologists joke).
I'm trying my hardest but can't get the joke it must be bad, take it to the Fringe next year
@ Ming 😆
I've looked at how the original builders used their bigger stones to join both sides of the wall together.
That's what the drystone builders do, down in Cornwall they use a completely different process, walls are much wider at the bottom, and are basically a soil core with stone set into the sides, tapering upwards, with a soil cap, allowing grass and trees to grow on and through the structure. Old walls look just like hedges, until you see a small patch of stone showing through.
It's not uncommon down here to see walls repaired with cement, and a cement cap put on top, rather than a row of upright stones, just because it's (relatively) quick to do without the skills (and money) necessary to do a proper drystone repair.
Good repair job, McM, should last a good few years.
The stones that cross through the wall and usually stick out past both faces and give the wall strength are known as headers
The foundation is just big ugly stones no concrete to be seen and the tapering of the wall is called the batter never plumb or worse still hanging
