Friday, February 24, 2012

Tolerances are a virtue

The art of dry stone walling requires knowing the tolerance level of the stones you are using. 
If you impose a 'zero level' of tolerance on a stone material you create an uninteresting wall.  

Stones offer us a lot of opportunity to put them in the wall in interesting ways, not just structural ways, and not always exactly "by the book". Stones are individuals and they are fundamentally very tolerant.  If you refuse to work with their tolerances, or insist on minimizing them, you are not doing the stone or your wall any favours. You will have a minimally interesting wall and while you might impress your colleagues with your abilities to make the stonework look like block work, there is really no need to do so. 

The trick is knowing and maintaining tolerances and working with the idiosyncrasies of the stones rather than trying to be in control all the time and shaping the daylights out them.

Andy Goldsworthy said that complete control can be the death of a work.


  1. This is so true for sculpture too. I've worked, and overworked, a piece, until it has lost its life and vigour and the stone no longer proud. Listen to your stone!

  2. Great post today, but what about tolerating a different style of building than your own? I have noticed reading your blog that you post about this topic once and a while. It seems that the one style of building (more shaping of the stones) isn't your forte. But to some i'm sure it is a beautiful look wouldn't you agree? I think with stone work and life in general we need to tolerate each other for our differences. I think you need to understand contrast more. Because without the one style that you don't appreciate, you wouldn't have such an appreciation for the style of building you do prefer. I think saying that the one style is "uninteresting" is a form of intolerance on your behalf. As Ghandi said "Anger and intolerance are the enemies of correct understanding." Maybe your intolerance to this other building style is hindering your full understanding of stone. The world wouldn't be a very tolerant place if everything had to be one way, now would it? I would love to get your feedback on this.

    John P.

  3. Thanks for these thoughts John; very much appreciate your weighing in on the subject.
    I was hoping to stimulate some discussion on this subject, and I see that I have.

    I have put my ideas on different walling styles out there on occasion to see what people think, and while I agree with you, and in fact advocate for more tolerance all round I notice that there has been a tendency of course wallers to elevate formal tooled walling above the wide spread vernacular random walling styles usually seen here in North America and in fact all over the world.

    I spent more than two decades learning and practicing (wet) masonry and countless hours shaping stone and laying it in courses. It is a valuable skill and I wouldn't suggest anyone not endeavour to master the skill but I do think, as you say, that people should be able to make a choice. They should not feel like they are lesser wallers for choosing to build walls leaving their stones less knocked around.

    I would liken the whole subject to bread: when you go to the convenience store to by bread, most of what you find there will be plain white bread. It's apparently what most people like but perhaps a bit bland and lifeless. In this instance I was advocating that the addition of other more nutritious, more whole grain, less bleached, less over-manufactured types of bread be made more available to the public or at least be promoted better in terms of competing with the revered brand names like Wonderbread. - all in the name of tolerance.

    1. I think overworking stone is a problem of mine. I have a habit of beating nature into submission when I think I should be trying to work with it instead. Damn OCD! If only I had someone to give me electric shocks when I start getting out of hand..

  4. Hey John . Don't be too hard on yourself, or the stone.

  5. John Thanks for taking the time to reply. Lets keep this discussion going. I come from a large line of Scottish stone masons, my great grandfather, grandfather, 2 uncles, father and older brother are all masons. I to have spent countless hours on a stone table facing stone. Maybe the reason I went the other route with stone and studied geology and now work in an office, haha!. But in my travels across Canada I have yet to notice but a few well built historic dry stone walls, that are more than just a stone row or a quickly stacked field wall. So when you talk about local vernacular I'm unsure what you are comparing to? The level of craftsmanship in the stone rows and quickly stacked field walls is very minimal. Maybe this is just my bias opinion with my heritage being from the UK, and I tend to compare the dry stone walls here that I see on your blog to those I know and have seen overseas. Maybe your talking about the local vernacular being the walls you have already built? A bit of a unfair comparison then since the local style is still being established. Your thoughts?

    Being a fan, like a lot of us of Andy Goldsworthy, I have most of his books and have made an effort to visit a lot of his instillations that are still around. When I look at some of his walls that are built by masters from the UK, there are a lot of shaped, tightly fitted stones in some of those walls. To me they look great. Also last year when you were on your tour of england you talked with a master waller over there Andrew Loudon, who worked with Andy G. After reading your post back then I researched his work and came across the most beautiful water feature that he had built. I'm sure you know the project I'm talking about, there was a dome over the water. I have to admit that I left a picture of that dome on our family computer desktop for a while. But that to also had a lot of faced stones and the stones all coursed. Is that the type of work that is the "wonderbread" of dry stone walls?

    To me personally I like nice tight stone work, with nice lines and a beautiful plane along the face. I'm not a dry stone waller but have helped on large structural mortared walls and my grandfather always told me that strength in a wall should always be number one. And with the absence of mortar you would think that tighter fitting stones would be a lot stronger? I follow your blog and have the understanding of dry stone work that friction is the key. stones should touch each other as much as possible to help the wall stay together. Am I wrong?

    I think it's just a personal preference on your behalf isn't it? It's tough living in a world with such a wide array of people and differing opinions from our own. Everyday poses challenges for us to practice tolerance and understanding. Once again I would love to keep this discussion going and look forward to your thoughts.

    John P.

    1. Hi John.

      The Wonderbread comparison was maybe a bit unfair.

      However stones like wheat can loose a lot of their goodness by going through too much processing. People with very good intentions still have to be careful about over working both 'substances' until most of their inherent value is lost. I am indeed reacting to seeing stone be made to fit so tightly together that is actually an affront to their nature. But no, I dont think the stones in Andy L's piece you mentioned were over worked.

      Perhaps the worst examples of overworking involve short cuts using saws and grinders. Other examples where the stone has been laboriously chiselled hammered and shaped, have been done so merely to reveal (and yes this purely my opinion) an over zealous commitment to the formal 'look' of the wall , not any particular preoccupation with making it any more structural. Were they making it any more 'structural'? Not necessarily so. The joints also might look very tight on the surface and perhaps be not actually fitted as well on the inside as less 'squared' stonework.

      Another thing to think about is that certain well fitted stone walls in Ireland and elsewhere in the world, gain their strength by strategically employing a relatively smaller number points of contact. It could be argued that by working stones to the degree that they have such flat planes of contact between them, there is actually less gripping/friction strength, and so isn't necessarily the best (or the only) structural way to build with stone. I think Sean Adcock addresses some of these issues in one of his recent issues of Stonechat.

      There are many examples of stonework that are both visually stunning and structural. Who is to say that the squared stuff is the best. Having said that I have always liked the look of good Scottish squared stonework in the old historic stone houses I have seen here in Ontario. I built and rebuilt walls in this style for many years. I am determined however not to give in to the argument that this kind of work is 'better' than others. There is a free-style stonework which lasts just as long, which I have admired on old barn foundations , out buildings, walls and other structures both here and abroad, and honestly, in the end, I find it more interesting, and sometimes a little less pretentious.

      Maybe I am a bit one-sided. That may be partly due to the fact I have endured 'course' comments and criticisms because of my commitment to building with and maintaining a solid appreciation for 'unworked' stone in good dry stone walls, even if they often are less 'coursed'.

  6. i think a person can build a pretty tight wall with flat rock and not have to shape very much or at all, also smaller pieces of rock lend themselves to fitting leaving smaller gaps. But with polygonal rock like basalt, which is about all we have in Oregon there seems to be more shaping needed not just for aesthetic and/or obsessive reasons but for structural considerations. A rock with a big bulge on the side which you intend to lay it would be much more stable if that bulge was taken down. Also the tolerances with polygonal rock are much greater because you end up with large triangular or other shaped holes. You then have a choice, to leave the hole, fill it with the best pin you can find, which is some times nice and tricky too if you can poke it through from the back so it can't be pulled or fall out, or you could shape the neighboring rocks to fit tighter, or take a section of a neighboring rock out so you can fit a larger rock in there.
    Sometimes I look at your pictures and I think, "i sure would like to get some flat rock like that and leave my hammers to rest a little more." But we have to pay $400 a ton and up for rock like that. And sometimes i look at these sandstone and limestone walls and think it must get boring only having flat rock.
    I suppose you might say I shape too much if you saw me work, but save for the occasional obsessive moment, I feel like I am doing the bare minimum necessary to make a more structural wall.
    Additionally much of our rock is brittle and has fractures that are ready to break which will be revealed with a hammer. Sometimes some of my nicest rocks break in half with the first strike of the hammer. Leaving me disappointed that I can't use it but also glad I didn't.
    Walling styles and technique are as different as the rock that is being used, and the person who is building. There is no "best" way.
    Some people make rocks "sing" by beating them others by leaving them alone>

    1. All very good points Rob. Thanks for sharing your thoughts.