What lies beneath

New trees have been planted in Cavendish Street, Enmore, but for pavement fanciers the interest lies in the method used to install them. The process was far more complex than simply plonking a tree in a hole. It involved such things as ‘in-road planting’ and ‘structural soil’ and ‘plastic cells’ and ‘permeable paving’ – all designed to address ‘multiple issues, including impact of trees on infrastructure, safety of footpaths, enhancement of the urban tree canopy, landscape amenity and urban water management’.* And preventing the road surface from cracking or caving in.

Marrickville Council seems pretty pleased with the project, which is the first of its kind for this municipality, and maybe for the whole of Sydney. It’s been interesting watching the process, but I have some misgivings.

Cavendish Street, Enmore NSW, June 2014

It all started more than three years ago, when Marrickville Council began removing very large fig trees from the footpaths on the street. Although enjoyed by birds and bats, these trees broke up the paving and invaded underground pipes. I wrote a blog post about local mourning when the first tree was removed.

Cavendish Street, Enmore NSW, October 2010

‘Tree replaced by cement!’, Cavendish Street, Enmore NSW, October 2010

The story resumes in April this year, and here’s how it goes. The Council excavates three huge rectangular pits in the street, digging deep down into the clay beneath the surface of the road.

Cavendish Street, May 2014

Cavendish Street, May 2014

Underground infrastructure, including gas pipes, is adjusted and gravel is spread in the bottom of each hole.

Cavendish Street, May 2014

Cavendish Street, May 2014

Next, a layer of large plastic cells is positioned in the pit and ‘structural soil’ is tipped in between them. Another layer of cells and soil is added, this time with a rectangular hole in the centre fenced off with plywood formwork. As I understand it, the plastic cells act as support for the roadway above; the structural soil is a mix of gravel and loam that resists being compacted and allows tree roots to spread and grow.

Cavendish Street, May 2014

Cavendish Street, May 2014

Over the soil comes a layer of geotextile then another layer of gravel.

Cavendish Street, May 2014

Cavendish Street, May 2014

Concreters build retaining edges around the central tree hole to form a ‘blister’. This will prevent cars bumping into the tree trunk.

Cavendish Street, June 2014

Cavendish Street, June 2014

Permeable pavers are laid. Rain falling on the road will flow towards this area of porous paving. This means that street run-off will infiltrate the tree pits instead of gushing down the gutters and into stormwater drains.

Within a day or so, on a nice rainy morning, advanced trees are lifted into the central hole, the formwork is removed and more soil is tipped around the large root ball. The three trees are Waterhousia floribunda ‘Green Avenue’, a cultivar of the rainforest Weeping Lilli Pilli that is expected to grow to 16 metres.

Cavendish Street, June 2014. All photographs by meganix.

Cavendish Street, June 2014. All photographs by meganix.


The project is not quite finished. A garden will be planted inside each blister. But the safety fencing has been replaced by witches’ hats and the official photographer has been sent to take photos for Council publications. As the unofficial photographer and busybody I’m rushing into e-print with this blog post.

In my next post I will talk about how my admiration for this aboricultural and civil engineering feat is tempered by reservations about the push and pull of local council policies.


*Marrickville Matters, December 2013, p.9.

Hard rock

Service lane off York Street, Sydney.

Service lane off York Street, Sydney.

The remnants of asphalt and concrete, and the old paving stones underneath, give this laneway in central Sydney a pleasingly shabby appearance. The stones are not cobblestones – as I have been known to mistakenly call them – but pitchers, and in this case pitchers of trachyte. A pitcher is a rectangular stone paving block about 22 cm wide, 30 cm long and 15 cm deep. Trachyte – like granite – is a hard, impervious, igneous (volcanic) rock.

I learnt this from a recently published book, Sydney’s hard rock story: the cultural heritage of trachyte. With its many beautiful illustrations, the book tells a fascinating story.

Quarried from Mount Gibraltar (the Gib) near Bowral in the NSW Southern Highlands, trachyte was first used in the 1880s for paving cubes and for kerb and gutter stones in Sydney, replacing the sandstone flagging that was too easily worn away by the city’s increasing traffic.

But when the durability and imposing appearance of the Bowral trachyte was recognised it was soon incorporated into the design of many grand buildings and monuments, complementing Sydney’s characteristic golden sandstone and investing the buildings with a sense of strength, solidity and permanence. A special feature of Sydney’s hard rock story is its trachyte walk through central Sydney, which takes the curious ambler past over 30 buildings in just a few city blocks.

In parts of Sydney, such as the service lane I photographed, trachyte paving can still be found. And despite the efforts of recent City Councils to remove it, much of the original, roughly-dressed trachyte kerbing and guttering remains as well.

You can find out more about this lovely book at the website, Sydney’s Hard Rock Story. Here are a couple of photographic excerpts:


The Sydney City Council began to use trachyte for kerbs and gutters in the 1880s and the kerbs at the edges of York Street, the ‘frames’ of the drainage inlets and the stormwater lintels are all made of cut trachyte blocks. Similar kerbs, still displaying the textures made by the masons’ tools, can still be seen in almost all of Sydney’s streets.


The former Bank of Australasia (now ‘Paspaley’), on the Martin Place and George Street corner. It was the American architect Edward Raht’s second Sydney building, designed in 1901. The entire building is faced in trachyte, with walls of rock-faced ashlar. The coat-of-arms and the sea-shell motif at the corner pediment represent some of the most detailed trachyte carving in Sydney. The building has two large basement levels which extend outwards for 5 metres beneath Martin Place.


Sydney’s hard rock story: the cultural heritage of trachyte, by Robert Irving, Ron Powell and Noel Irving, published by Heritage Publishing, Sydney and Leura, 2014.

Christian graffiti


Following on from my earlier post about Eternity, I’ve noticed that someone regularly chalks Praise God! on kerbs in Glebe Point Road (Sydney), often at bus stops. It’s not the only piece of Christian graffiti I’ve come across on the ground, although I have more frequently found graffiti that mocks religion. Photos of these jokes and snide remarks are posted in my Pavement Appreciation gallery.


People have used the pavement for affirmation of their Christianity from very early times, as evidenced at the remains of the formerly important Roman city of Ephesus, located in the east of what is now Turkey. Ephesus is mentioned in the Book of Revelations in the Bible. Among the archaeological finds are symbols carved into the paving stones of the Arcadian Way. These symbols are made up of a set of Greek letters that have been interpreted by classics scholars as standing for ‘Jesus Christ Saviour Son of God’.

The following photograph was posted by aaron60 in his Ephesus Travel Page on the Virtual Tourist website. At least two of these segmented circular Christian symbols can be seen.



Bluestone symbols (Guest spot)

Melbourne footpath enthusiast Dimitrios Kianidis took the photographs for today’s post

I have found another person who likes to keep his camera pointing downwards – or at least, he has found me through the Pavement graffiti website. When Dimitrios Kianidis posted a comment on this site in 2011 he had already self-published a book called Footpath graffiti: Coburg & Brunswick. It contains nearly 400 photographs, mostly inscriptions in wet concrete. Leafing through them is like reading a funny little book of very short poems. Dimitrios wanted to capture the social commentary scratched in concrete. “Most are so-and-so loves so-and-so,” he tells me, “But there are other messages and drawings as well. My favourites are:  ‘The Aborigines own this land’, ‘Santo and the Corinthians’, ‘I love Harrison Ford’, ‘RIP Blair 2006’, ‘RIP Cliff’, and ‘Dan is average!’  to mention just a few.” There are only a few copies of his book, but one of them is in Brunswick Library if you’re interested in seeing it.

But Dimitrios’s latest discovery is, as he puts it, ‘a whole language of numbers, letters and symbols carved into bluestone pavers’. The purpose of these inscriptions remains a mystery, although Dimitrios suspects they indicate the location of underground utility pipes and junctions. Any suggestions from knowledgeable blog followers would be welcome.

The ‘EA’ is particularly striking. “It is my favourite because it’s unlike any other that I have found. It’s beautifully carved and takes up the width of the paver and is visible from a short distance even to the casual observer. It’s in Albert Street on the pavement beside my favourite church too, St Patrick’s Cathedral.”