Bridge Renewal in
Port of Sale - Wharf Precinct
From the River Port of
Sale in Gippsland come two semi-loads of hardwood timbers - stringybarks
and ironbarks -
salvaged from renewal works on the old Park Street Bridge.
The old timber road bridge
gave access to the south bank of the historic wharf from the commercial
centre of Sale.
In addition to the 180 x
90mm decking, the bridge featured running boards 200 x 50mm which
display a weather-checked upper surface.
This look is always
popular for furniture and outdoor structures.
90mm bridge decking boards
50mm bridge running boards
Recycled Ironbark 300mm
A few years ago, demolition works finally went ahead on the old Empire Hotel in the west end of Hunter Street in Newcastle.
The building had stood vacant and unloved for many years
- but even another decade of leaking roofs would not have worried the deep ironbark joists on the first floor.
They had weathered to grey over the long period before demolition and then spent a
few years neatly stacked and looking self-consciously ancient at the
very woody-vibed Laurens Hall venue (closed now and fondly remembered).
Dressed to a deep grape Hunter Valley red, these timbers are looking for a new life in a Victorian building project.
Messmate 270 x 40mm
Long and true upper-floor joists
300 x 50mm from a Preston warehouse have been dressed and straightened for furniture and
joinery board, retaining good length.
Wharf Timbers Resawn
In the vast front yard at Timberzoo you can now discover a range of recycled Ironbark, Grey Box, Turpentine and other durable species which have been resawn from wharf and bridge girders salvaged
in-the-round. What's the story behind the wormy squiggles on the sawn timber
faces? They look so artfully etched.
Marine pilings in saltwater commonly show moderate to intensive marine Teredo borer tunnelling at the wet end of the pile and not much at all in the end buried 3 to 4 metres in anaerobic mud. Piling salvaged from turbid estuarine waters
- or from a surf break - have only a scattered texture of borer on the
sapwood-heartwood margin. Worm activity seems to be at its most intense near the surface in clear and relatively calm waters. It can devour the pile at the low-tide mark to a point of near separation from both ends. In recycling, this hour glass section is always docked before reprocessing and is offered as a landscaping item. It has become a popular mount for street numbers and letterboxes in a coastal landscape.
In best case scenario, borer activity is restricted to the outer circumference of the round pile
- the sapwood and outer cambium - the depth of penetration is
species-dependent as much as habitat. Turpentine is the most resistant eucalypt in marine waters. White Mahogany, Grey Gum and Grey Box are next
- followed by Red Ironbark, Tallowwood and Bloodwood.
Lower durability marine pilings are often wormy to the core of the heartwood. Accordingly
- there is a wide spectrum of scribbly borer intensity in the recycled stock available for sale. But the wood adjacent to furrowing is solid and not in any way decayed
- and it is this attribute that makes the texture appealing. It resembles wood-carving rather than predation.
|Teredo borer becomes inactive once the piling have been salvaged. Rapid drying of the piling on land is not good practice and they accordingly spend several years buried in damp sawdust at the
mill in order to season in a gradual way. An acclimatisation of sorts
- and probably the best way known in recycling to prepare the round for reprocessing.
|Roughly 10% of resawn stock is characterized by intense scribbling and would suit decorative uses such as mantles, fence posts and supported beams. These beams have a lower structural rating than the rest
- but you are free to choose posts and beams that suit your project. Timberzoo staff will advise on suitability and spend the time with you in a selection process.
The same dimensions of beams and posts can be specified in wharf piling
- or in Sugar Gum (FSC-100% certified) - a DC1 (Durability Class 1) species found inland and unaffected by marine borer in their finished state. Both wharf timbers and Sugar Gum are resawn at
Yarra Timber Salvage, Lismore, in Victoria’s Western District by veteran sawmiller and recycler Rob Horner. Horner is vitally involved in farm forestry work in the Lismore district where extensive mature sawlog stands of Sugar Gum are found in verge plantations that have been planted, harvested and replanted many times since the 1890s.
Timberzoo has recently gained FSC Chain-of-Custody certification for remilled Sugar Gum and for recycled timbers and the following dimensions of timber are available in both
FSC Sugar Gum and Recycled hardwoods (DC1 durable).
||300 x 300mm
||300 x 200mm
||300 x 75mm
||250 x 50mm
||250 x 250mm
||300 x 100mm
||200 x 75mm
||200 x 50mm
||200 x 200mm
||200 x 100mm
||150 x 75mm
||100 x 100mm
ingenuity: sawdust burial ground for piling provides excellent
Ironbarks 225 x 40mm
|Rail Bridge beams 250 x
180mm from creek culverts on the Moree to Mungindi branch rail line were resawn to
250 x 50mm board in the winter of 2016 and have been acclimatising in-stick in the back paddock at Timberzoo. After six months in the open air, the boards then spent several weeks in
Timberzoo's drying shed before being taken to the planer for dressing and straightening. The result is impressive – boards around 2.7m long with rail spike penetrations and carbon staining on a rustic wild textured board that would suit an alfresco table or joinery piece. A limited number
- around 300 lengths - in stock now.
sleepers are a large dimension sleeper 250 x 180mm used on rail
merge points and junctions,
and across larger spans on creek culverts and small bridges
The protracted process the Mungindi Ironbark 50mm board underwent at Timberzoo has surprised some builders and architects who inquired whether the timber
- being recycled - is not fit for purpose and well-seasoned at the time of resaw. Why the seven month timeline in
In truth the term 'seasoned' timber is entirely relative to purpose anyway. Specifiers often add the proviso that the timber must be seasoned
- giving no indication to suppliers of intended use. This proviso should be specific and calculated to suit the application.
Joinery timber and flooring must be seasoned to
9-11% moisture content in southern states to be in equilibrium with an internal
air-conditioned and dry environment. Window frames, F27 hardwood, decking and cladding have a different kiln drying schedule
- and are in equilibrium with outside humidity at an average 15% MC.
In cross-section, timber has a moisture gradient
- rather than a single moisture content. The moisture content of the core of a large old recycled beam exceeding 150mm in thickness is
3-4% higher than the case (shell or capsulation). So when resawn from this larger flitch, the case of a 50mm timber board needs to find a lower MC that is at equilibrium with its surroundings
- while the core finds a more minimal change in MC over a slightly longer time.
If you are specifying timber that is
'seasoned' for a very unforgiving application and wanting a resawn size - you can expect that supply of board will be possible in a few weeks
- but for truly seasoned timber, it is far preferable to allow the same time we did on our Mungindi Ironbarks for the new sawn dimension to acclimatize.