Tuesday, March 31, 2015

Well-designed, well-built obsolescence.

Rendering showing the proposed design and placement of a old ruins installation that I was commissioned to build on a property not that long ago.

Part of the allure of ruins is their rustic beauty. Many seekers of such an aesthetic enjoy being around old looking garden structures because they are usually made of a very attractive material - stone. 

Stone ages well. It looks good when its old. Things that are made of other materials decay and deteriorate and rarely look as attractive. 

People don't like too much dilapidation.  Most types of deterioration are not beautiful or all that inviting.  Let's face it broken plastic, wet cardboard, warped plywood, rotting beams are not as attractive as stone. It has a dignity in decay.  It has a noble decline. Even for those who are not sure they like the look old things, stone is a perfect medium to explore and not get too depressed . For this reason stone buildings made to look unfinished or partly fallen seem attractive because their obsolescence is planned.  There is a sense that we are still in control.

It is curious how reluctant many masons, even dry stone wallers, are to produce something that looks less than new and perfect. They don't want to give up any control. It is as though they are not at peace with the 'inevitable', They are not reconciled to the fact that even stone buildings deteriate. Stone is not immortal and stonework contrary to popular opinion isn't going to be around forever.

A stone waller who is able to make a structure genuinely look like a ruins is not so insecure. He is not afraid to explore the effects of time. When asked to build a dry laid ruin he can dedicate his attention and skill to celebrating the limitations that time imposes (and will impose) on every stone he places. There is a satisfaction that comes with building something that looks like it has come to terms with the inevitability of time.

History lingers in stone buildings, even ones that are not that old. This is partly because the stones are so old already. They have history.

Combine this quality of stone with a vision for what would look appropriate on a property and a mason who knows what he's doing and you can create a very believable, very attractive tribute to the ephemeral. There will be this subtle dynamic of contrasts - the durability of stone purposely arranged in a state of impermanence.

The craft of aging something, be it distressing a piece of wooden furniture, painting objects to look old, or making any number of antique artifacts, is not as easy as it looks.The same is true for making stonework look old. A proper ruins is not something you construct by building it badly.

Rev William Gilpin in his essays on the 'picturesque' wrote in 1794  that " There is great art, and difficulty also in executing a building of this kind. It is not every man, who can build a house, that can execute a ruin. To give the stone its mouldering appearance — to make the widening chink run naturally through all the joints—to mutilate the ornaments — to peel the facing from the internal structure — to shew how correspondent parts have once united; tho now the chasm runs wide between them — and to scatter heaps of ruin around with negligence and ease; are great efforts of art; much too delicate for the hand of a common workman; and what we very rarely see performed."

To accidentally come across a well built stone ruin is a magical experience, no matter how old it is. To be given the opportunity, and to have the ability to make such a relic, is a special privilege. Those of us who work with stone have the responsibility to do it right. If it looks too new or too perfect it will defeat the purpose. If it is built with too little care, in terms of it merely ending up looking 'bombproof' or not showing any hint of impermanence, people will wish it had never be put there to spoil the view.

Monday, March 30, 2015

Found Out

During a memorable dry stone walling workshop a few years ago in British Columbia I announced to the students that we were going to have another, what I like to call, 'walk around'. This is where everyone stops working to discuss the quality of the workmanship on the wall to whatever height it has already been built.

After going over a few sections commenting on the placement through stones and how well the hearting had been done, etc, my students watched in anticipation as I removed a stone from a questionable part of the wall saying, "Let's see if the person who put on this stone 'hearted' it properly underneath ". 

Not only was there very little hearting done below, a name tag lay inside the wall cavity. It had obviously fallen off her jacket. Everyone groaned. How could she deny she had been working there?

Jane quickly protested. "I've been framed!"

Sunday, March 29, 2015

A Farley Folly

A recent photo taken on Mary's visit to Claire Mowat out east shows the 'Alban Beacon' looking much the same as it did  when we built it for Farley, nine years ago. 

Here's the story...

In early August of 2006, we built an Alban 'beacon' on the Canadian Atlantic coast. The installation was erected for Farley and Claire Mowat on their summer property near St Peter's Nova Scotia. Mary and I and, Irv, a local lobster fisherman and good friend of Farley's, gathered suitable rocks from below high tide mark and assembled them into a unique 8 foot tall dry stone pillar on a point of land within view of the Mowat residence. 

The Beacon was to replicate one of the many dry laid structures built by a pre-Viking people who according to Farley Mowat, came to Canada in search of walrus skins and tusks in fragile hide covered double-enders from early Britain. 

According to his fascinating book The Farfarers, many ancient conical piles of stacked stones or 'Tower Beacons', (much like this newer reproduction) can still be found in Greenland, Labrador, Newfoundland and other parts of Arctic Canada. 

They stand from 7 to 14 feet high and range from 4 to 6 feet wide. Each dry stone tower has a unique shape. Often these towers are found in groups or pairs and it is believed they were erected as markers to help ancient sea-faring people find their way around the indistinguishably riddled shoreline. The beacons looked different enough in shape or in groupings to discern them individually, so that the walrus hunters would know their precise location along the coast.
This new dry stone beacon not only added a sense of history and mystery to the rugged Canadian coastal scenery, it stands as a more accessible tribute to our prehistoric dry stone heritage.


Not long after their return to the property each summer Farley would write back to us reporting on the condition of his favourite beacon. These hand typed letters would usually say something like "I am pleased to inform you once again that there has been no damage from high tides, strong winds, freezing snow or pirates."

Saturday, March 28, 2015

Landscape Cloth, Top Soil, Sod On and Photo Ops

Next, sheets of landscape fabric are laid over the gravel. 

Then a layer of soil is added.

Next rolls of sod are laid, the first layer is laid upside down Then next, green side up.

Finally someone has to stand on the bridge and lots of photos need to be taken. 

Friday, March 27, 2015

Backs to Bridges

This is how the back (top) of the bridge looks before adding a horizontal layer of flat-ish stones

After all the voussoirs are firmly set in place,the back of a bridge (the area that is walked on) should be thoroughly pinned and then built over with random shaped filler stones. They don't have to be really good stones. 

All of them can to be laid on their flat to within 6 inches of the finished height of the walking area bridge. The stones should be fitted together carefully so they don't rock. 

Then the parapet or border wall of copes are laid the way you would standard vertical coping stones on a dry stone wall.

A layer of gravel is then added in wheelbarrow loads over the back of the bridge.

This is what it looks like before the landscape fabric is laid down

Thursday, March 26, 2015

Canadian Pre-Configuration

Here in the picture you can see a sort of pre-configuration of voussoirs being arranged at a bridge we built near Montreal. 

Having spent time sorting through the pile of material and choosing the best ones, rather than fitting them one at a time over the actual bridge form, we pre-fit them in an assortment of rows according to size nearby first. This way it was possible to choose all the similar width stones and prop them up together in rows to see how they would fit. 

If you decide to do this, choose a flat area and lay plywood out wide enough to accommodate the dimensions of the form which is a rectangle the 'width of the bridge' by 'the length of the arc over the span' This length will be slightly longer than the span across the bottom of the form.

Lay the stones face down on as if you were pitching cobblestones on a path, only upside down

The idea of preparing all the voussoirs beforehand to one side of the bridge is to be able to work together as a group better. Sorting and moving them around is more convenient. It also facilitates a variety of configurations to be tried out rather than having no opportunity to undo the rows that would have been placed on the bridge if they hadn't been pre-configured. 

It also means more people can work on the project at the same time, rather than all be crowded around waiting to put stones over the arch one at a time. 

The putting together of the arch takes less time since the voussoirs can be easily moved one by one and re-fit on the form. When they are set over the bridge form, each voussoir is spread with small wedges so that they all fan properly,

Care should be taken when people are transferring the individual stones to the bridge, not to mix up the rows, or reverse the sequence of voussoirs left-to-right. 

Numbering them or spraying coloured dots on the stones helps remove confusion.       Or does it?

Wednesday, March 25, 2015

Building Horizontally Up To And Over the Voussoirs.

A lot of the final look of a stone bridge, and how satisfying the whole structure is visually, is determined by the pattern of building stones that form the approach to the arch (the skewback) joins up with the individual voussoirs. Care should be taken to find shapes that match. This can be difficult because the tops of the radiating arch stones create acute angles. These triangular shape spaces that are difficult to fill. This can be a problem both visually and structurally. 
Too many small stones at the meeting line of the arc and the skewback will look busy and will be more likely to fail over time. 

The stones in a bridge have to be laid into the structure much like a dry stone wall. There should be no 'trace' stones or 'shiners' (split stones that are taller and thinner than they are wide and deep). In other words and stones used in the bridge should have their longest lengths oriented on their flat and perpendicular to the plane of the bridge. 

Stones that adjoin the arch need to merge nicely, but also be laid long enough into the body of the bridge so as not to be likely to come loose and fall out. Again, if too little attention is given to the joint where the horizontal builder stones and the voussoirs meet the structure will look crude and poorly settled.

In the photo above the stones are being built up over the arch  using a combination of level bedded quarried limestone and local granite fieldstone. Coursing helps to keep things looking tidy.

The cope stones over the top also form the outer edge of the pitching of the walking surface which we will discuss later.

Tuesday, March 24, 2015

More on taking out the form.

Sometimes we remove the former from underneath the arch before the bridge is completed.
In the case of Hubb Creek Bridge one of my students, a landscape instructor at Fanshaw College in London had to leave before the two week dry stone bridge workshop was over.We knew that all the voussoirs in our bridge were fitted well and firmly locked in place with wedge stones and pins.

The arch was tight. 

Almost all of the work on the sides (tails? ) of the bridge had been completed but not the top. 

I knew the bridge would be able to hold itself up even without the addition of weight to the top, though this does give it even more strength.
My student was eager to see the form taken out before he had to go.
We smashed out the supporting cement blocks, it dropped down a satisfying 3 or 4 inches.
The bridge didn't move a fraction of an inch.
Next we unscrewed the scabbed plywood holding the two halves together, removed many of the lose 2x4s over the top of the form and then carried the right half away.
The second half gave us a bit of a battle as of the form was still pinned at the north east springer. 
With pry bars and some good whacks with a sledge hammer the former came free and four of us removed it.
The arch looked very strong and beautiful. there was no concern that it might fall down.
It do remember it looking a bit anorexic though.
What was left to do in the next two days was to add more 'meat' over the arch in horizontal rows of builder stones and to build up  the walking surface, add gravel,then landscape fabric, soil and turf.

Monday, March 23, 2015

Taking Out The Former

In searching for good photos for describing the removal of the form (sometimes called the 'former') on one of my dry stone bridges, I came across this footage from a news report the CBC did a while back on the bridge we built in Russell Ontario, near the nation's Capitol.  

CBC  Building The MacDougal Bridge, 10th and 13th, 2009

The second link shows the removal of the former.

CBC Removing the Former, August 19th, 2009

Interestingly, a rival TV news crew arrived in their truck minutes after the wood support had already been successfully removed and filmed by the CBC. 

The head guy of the other TV station asked if we could put it back in again and film us pretending to take it out for his viewers, (even though the station had been given ample notification about when we were planning to do it ) 

Needless to say I did not entertain the idea of faking the removing of the former.

Sunday, March 22, 2015

Copes and strings on bridges

Thin flat unshaped stones were used to form more of a rustic cope stone border either side of the footpath of Springdale Bridge. String lines are used to determine the general curve of the top of the copes over the bridge.

Whereas fatter squarer pre-shaped ones were formally fit on the parapet of Crown Bridge.

String lines are used to get keep the stones flush with the sides of the bridge.

Generally string lines are useful at all times on bridges in order to keep everything flush and plumb. Most of my bridges don't have a batter because the dynamics of the arch gives a bridge enough strength not to have to depend on battering the sides (leaning the sides in slightly) the way you would a narrower free-standing dry stone wall.

Friday, March 20, 2015


Walls in the spring 
   a beautiful thing. 

Summer walls too 
don't wreck the view.

Walls in the fall
not awful at all.

  Walls in the snow,  

   are most apropos.  

but walls in the spring 

are a beautiful thing.

Thursday, March 19, 2015

Making a Hell of a Bracket

The handrail idea we employed and at the Macdougall public dry stone bridge we built in Russell Ontario was something Scott Cluett came up with to solve a common bridge issue. 
How to keep the width of the arch to a minimum and still have handrails.
It is very time-consuming and a lot more work to build a bridge wide enough to accommodate sufficiently wide cope stone borders or build structural dry laid parapets. Having the handrails secured beyond the 6 foot width of the bridge gives all the available surface for people to walk on .
After we went over the final shape and dimensions, Scott who is a part time blacksmith ended up fabricating the metal brackets for this bridge and Kay's bridge in Landon Bay. 

The brackets are made of heavy steel and have a thick rust resistant coating. The brackets which span the width of the bridge and have sockets at each end, are built into the bridge while it is being made just above the voussoirs. Stones are fitted around them and then over them, with a final layer of pitched stone ( or thick flagstone paving) over that, so that they are held quite secure. Metal or wood posts can be inserted into the square 4 inch sockets connected to the brackets and then handrails attached to the posts.

Tuesday, March 17, 2015

Always have a good platform to work from.

Some dry stone bridges can be built without having to construct temporary bridges either side to work off of. This bridge in Russell Ontario had very little rise and the creek it went over was dry so our team could build the bridge and transport material across with no trouble. 

Bruce's Bridge had a steady stream going under the form while it was being built. The old wooden bridge was used as the new temporary platform while we built the new stone bridge.

At Hubb Creek Bridge in Prince Edward County we laid planks over the big barn beams that were supporting the bridge form in order to walk and carry material across to the other side.

You can see here too that because our 2x4s extended several inches past the form, radiating lines for the alignment of all the voussoirs had to be set up with strings, rather than try to follow the lines drawn on the plywood.

Monday, March 16, 2015

The charm of a bridge.

People have remarked on how natural the kind of bridges I  build look. I guess there is a simplicity of both form and function to their design.  A bridge made by hand, without machinery or power tools, will usually look more appealing than one where the material has been bullied and beaten into submission. 

I am dedicated to the idea that bridges don't have to look pretentious either. This means making them as efficiently and honestly as possible.  I imagine many footbridges back in the old country were built this same way. 

The skill of a mason is not determined just by their stone-shaping ability or how perfect their work is merely as a result of having chosen only the best material. It is based on an ability to work with stones that a less skilled waller might try to avoid. It means being competent enough to know when and where a challengingly irregular 'unshaped' (or 'unshapable' ?) stone could be used to 'do the job', just the way it comes out of the quarry, or collected from off the field.  

A bridge built with restraint (in terms of not overworking the material) is less likely to look annoyingly new and out of place, especially if all the faces of the stones don't all have fresh breaks and chisel marks on them. 

While it is important to fit every stone properly, bridge building is not about impressing people with your stone shaping skills. A bridge can be charmingly beautiful without seeming 'showy' or glaringly new-looking. 

Have you ever seen something new that looks so 'right' that it feels like it has always been there?  It takes a lot of invisible effort to make something appear effortless.  I know I have done my best when I can create a bridge where the maximum structural integrity has been achieved with the minimum of fussing and bothering about 'shaping' ( fixing ? conquering ? spotlighting? ) every single stone I touched.

Sunday, March 15, 2015


Here are various photos of some of the middle arch stones being fit between voussoirs assembled already positioned across the form on a couple of older bridge projects.

On a segmented arch these middle stones which complete the arch don't have to be special keystones, in that they don't have to be necessarily bigger or different than the other voussoirs. As long as they are properly shaped to fit snug in the arch they will work. 

As you can see, this middle voussoir on the Monarch Bridge we built is going to slip in very tightly. Care needed to be taken so that it fit enough to be snug, but not so tight as to force the other stones out of alignment. Some of the thickness of this stone needed to be chiseled away before it went in properly. If it had been too thick, and we had forced it into the opening, a bulge would have been created somewhere along the rest of the curve of the arch, and the integrity of the whole bridge structure would have been compromised. 

Here in this photo of the MacDougal Bridge in Russel Ontario, 
when Evan felt confident it was going to fit, the chunky middle voussoir was hammered down into place with a heavy stone.
It was pounded down until the bottom touched the wooden form, and thus completed the continuous look of the curve created by the other arch stones.  

The rest of the voussoirs needed for filling in the middle space that extends across the form are all carefully fit and pounded in the same way. Some of these last interior voussoirs can be difficult to wedge all the way to the bottom. You may not be able to see if they are flush the intrados, but you can tell when these stones go down far enough because of the sound of stone hitting against wood.

On another occasion at the Hubb Creek Bridge project a special 'keystone' did have to be made. Prior to the arch being built a suitable stone had been chosen and the letter K (for Karlo Estates) sandblasted onto the face. 

When the time came to fitting this pre-made keystone into the space left between the other voussoirs that we had already set in place, I was disappointed to see how loosely it fit. 

In order to correct this and not have to take apart the other arch stones that were fitting so well we decided to cut out a portion of the form, to allow the keystone to fit down lower and so fit more snugly between the voussoirs to the left and right. This turned out to be a perfect solution and ended up being a signature visual feature of the bridge.

As you can see, we were only able to do this 'recessing' of the keystone because the 2x4s that made up the supporting curved surface of the form, extended beyond the outer rib. This extension had been done in order to build Hubb Creek Bridge two feet wider than the 6 foot wide bridge form it had previously been designed for.  

Saturday, March 14, 2015

Beginning the rows of voussoirs

On a dry stone bridge the voussoirs are shaped as close to parallel bedded trapezoids as possible and then laid in rows optimally with their best face down and their longest length up. This first 'grocery bag' size/shaped voussoir is being pinned from the back

The closer that voussoirs can fit together at their faces ( the exposed intrude side) the better.

Avoid using stones for voussoirs that are more like triangles than squares (that is, ones that get too narrow towards their upper end when placed face down on the form)
If their sides don't fit well and lock, as they butted together along the row, try other combinations of voussoirs until they do. Each odd shaped voussoir should lock in somehow to the other or at least overlap on one side to the one next to it.

It is best if the stones in a row of voussoirs are all the same thickness so that the next stones can be laid across the joints. Sometimes a pair of voussoirs can be laid together to make up the height of the other stones in a row of voussoirs. 

These arch stones can be pinned with thin wedge stones as they are put in so that each one fits fairly snug in the structure as it is being built. Aviod letting any wedges slip down and  thus create pivot points between stones. The pins should be near the top and only be used to allow the faces of the voussoirs to touch, rather than be a place where the stones rock against each other. 

From the side looking across the bridge the voussoirs should all be set so that they fan out slightly along the lines drawn on the form. These wedges are pushed in just far enough so that the voussoirs keep their orientation. The final 'shimming' which locks things permanently tight will be done when all the voussoirs in the entire arch have been set properly in place.

Achieve the proper angle along the rows of voussoirs by pinning each voussoir (therefore effectively wedging it) is quite structural and can be done instead of having to shape every voussoir. By this method many useful, more random shaped stones, that have little or no taper, can be used. A more informal rustic look is created if enough of the stones in the bridge are pinned. 

Shaping voussoirs, by sawing and chiseling every single one  along their length to give them the slight taper required to fit in a radiating pattern (so that they are absolutely flush with the others) can become an unnecessarily time consuming job. 

More on this point tomorrow...

Friday, March 13, 2015

The Springers.

The springers are special arch stones. They are the first row of tapered stones that the rest of the voussoirs spring from
Their bottoms are level. Their tops (in a segmented arch) angle towards the centre point of the circle below the form.

Hopefully lot of them can be 'hand-dressed' from appropriate shaped rocks found in the tons of random material needed in the building of a dry stone bridge.

Some of them might need to be sawn.

This is done by finding a likely candidate stone for a springer and sawing straight lines at the right depth and correct angle, and then chiselling in the strips of material away. In the photo above you can faintly see the remaining saw lines after the material has been removed. A template was used to trace the angle on this big springer stone. 

It is the angle and shape shown in this diagram.

It is best if the springers made from the template have some thickness at the nose rather than have the stone come to a point, so that they are stronger and less likely to break .
This nose will become part of the intrado which is the name for the underside of the arch. 

Thursday, March 12, 2015

Supporting the Form

The form used for supporting a dry stone bridge while it is being built can be held in place in a number of ways. Most often temporary, fairly thick, beams need to be used for the form to rest on.These beams or heavy planks need to be positioned in such a way that they can be dropped down and the form lowered and slid out sideways after the bridge arch is built and has become self supporting. In the photo above the beams that support the form are resting on big stones bedded in the creek. Wedges will be slid between the top stones and the beams to bring the form to the correct height. These wedges will be removed later when the dry stone arch is completed.

The form for Crown Bridge was supported by a crib of cedars.   The posts in the crop running parallel to the direction of the bridge were knocked out after the bridge was completed so that the form could be lowered and taken away.

Springdale bridge in Port Hope was supported by 4 by 4s laid on 12 inch blocks. Later after the bridge work is done, the blocks will be smashed and the form will drop down.

On a couple of bridges I have used four pairs of these block wedges under the supporting beams.

Plastic is sometimes used between the wedges so that the wood doesn't bind when the time comes to spread them to lower the beams supporting the form.