Once the location of the wall has been decided, based on the Environment and Liveability Strategy (ELS) and Recreation Parks Plan (RPP) guidance, consider the appropriate embellishment level to suit the selected site.
Overarching design considerations:
A wall is a solid structure which may act as a retaining wall, or it may be free standing and provide a base for signage and artwork, or act as a seating wall.
Where a wall is over 1.0 m high, approvals are required.
Walls should be designed and certified by an RPEQ.
Retaining walls are structures erected to support an excavated or filled embankment to prevent soil from collapsing. Certification by an RPEQ is required, and the wall (including footing) must be wholly within the subject lot. Uses include:
To hold back soil between two or more different levels (the soil attempts to move down-slope due to gravity).
To improve access to and maintenance of a slope, such as equal access and for mowing.
Planter box to retain soil and contain plants.
Where seepage is anticipated, to form a retaining structure such as gabion wire baskets filled with rock and wired together.
Where a protective covering of an embankment is required to maintain the slope or protect it from erosion near a body of water (a revetment wall).
See the following:
Figure 2: Retaining wall types
Figure 6: Identify barrier type/retaining wall barrier with handrail (see LIM Walls - Positioning).
Walls over 1.0 m high are to be certified fit for purpose by an RPEQ, or an acceptable generic masonry block design by a recognised manufacturer, and are to include the following design features:
It is essential that the correct mix of mortar is used to prevent detachment of stones, rocks or other materials forming the wall.
It is essential that drainage is designed correctly to prevent wall collapse and to channel water flow appropriately.
The top of wall must be sealed to ensure no moisture can seep into the wall and diminish structural strength.
Fixings and anti-skate devices are to be stainless steel.
Walls for seating should be smooth at the top, between 450 mm and 520 mm high for adults.
Walls with electricals housed inside (i.e. for lighting), must provide maintenance access for in-situ repairs.
Where revetment walls and the like form part of, say, a grassed area through which there is unrestricted public access, refer to AS 2156.2 – Walking tracks Part 2 Infrastructure design for guidance about safety barrier types and ‘calculated fall height’.
A boulder wall is a free-form structure with the rocks placed in a random, natural way. Construction and materials are to comply with the following:
Walls over 1.0 m high to be designed by a suitably qualified engineer.
In geology, a boulder is a large rock with grain size usually no less than 300 mm. They may be small enough to move manually or extremely massive, requiring mechanical lifting.
Excavator operator needs to be licensed, experienced, highly skilled, and capable of selecting boulders suitable for placement to ensure structural stability of the finished wall.
Use an excavator fitted with a specialised rock grab to allow each individual rock to be turned to ensure it fits into the wall in the most stable and aesthetic manner.
It is essential that drainage is designed correctly to prevent wall collapse and to channel water flow appropriately.
Rocks should be sound and free from flaws including vents, cracks, fissures, foreign material, machine markings etc as these affect strength, appearance, durability, and proper functioning.
Rock type should match any pre-existing works.
Rocks are to be split faced, with the smooth undamaged surface used for the facing.
Rockwork should be adequately bedded in mortar with minimal mortar exposed, with excess raked from joints without decreasing stability.
Rock or stone cladding for wall facings and capping to be selected and split or worked to produce a consistent surface finish with joint size kept to an absolute minimum, unless stated on drawings.
Rock sizes to be laid to allow for close bonding.
All sharp faces to be chamfered leaving no machine markings and to replicate natural edge.
Boulder walls to be formed by placing rocks on the ground while ground formation work is being carried out, using approved site and imported rocks, bury two thirds by volume, with weathered exposed faces protected from damage.
A sandstone block wall is constructed by placing rectangular blocks of sandstone end to end to create a retaining, seating or delineation wall.
Construction and materials are to comply with the following:
The settlement of sediment results on the formation of horizontal layers/strata. All sandstone blocks must be laid the same way the rock was formed in the earth.
Blocks should not be laid with sediment layers vertical. This allows weathering to permeate the exposed layers.
Walls over 1.0 m high are to be designed by a suitably qualified engineer.
Laying
Sandstone blocks requiring mechanical lifting. The excavator operator needs to be licensed, experienced, highly skilled, and capable of laying blocks so that the grain is predominantly horizontal, to ensure a natural look to the finished wall, and to resist weathering.
Blocks should be adequately bedded onto a crushed rock footing to form a level surface.
Lay linear sandstone block walls so that any gaps between blocks are grouted to prevent entrapment.
Incorporate oxide colour in the grout to complement the sandstone.
Sand/cement mortar maximum grouting jointing 100 mm wide.
Sandstone blocks can be positioned as stand alone or in a linear set out with grouting:
Ensure stand alone sandstone blocks are laid with layers horizontal.
When some sandstone types are laid with their horizons vertical (exposed to weathering, rainfall), moisture penetrates the horizons and expansion and splitting can occur. Broken fragments which shear off could become a safety issue.
Wheel sawn
Wheel sawn sandstone blocks are:
a more formal finish
more expensive than rough sawn.
Consider grade ‘A’ wheel sawn blocks 1000 mm x 500 mm x 500 mm, for linear walls.
Six wheel sawn faces are required to allow the flexibility to lay the stone so that graining is horizontal, and to match face colour/pattern.
20 mm arris is required to all exposed top edges and grind smooth any sharp/rough edges and corners.
Rough sawn
Rough sawn sandstone blocks are:
a more natural finish
less expensive than wheel sawn.
Consider that standard rough sawn sandstone blocks have five sides rough sawn with one side left rough. This finish removes the flexibility to lay the stone so that graining is horizontal.
Construction and materials are to meet the following:
Walls over 1.0 m high to be designed by a suitably qualified engineer.
Rock walls are to have a footing which is suitable for the site soil conditions and designed by a suitably qualified engineer.
Rockwork should be adequately bedded in mortar with minimal mortar exposed, with excess raked from joints without decreasing stability.
Rocks should be sound and free from flaws including vents, cracks, fissures, foreign material, machine markings etc as these affect strength, appearance, durability, and proper functioning.
Rock type should blend with any pre-existing works.
Rocks are to be split faced, with the smooth undamaged face used for the facing.
Rock or stone cladding for wall facings and capping to be selected and split or worked to produce a consistent surface finish with joint size kept to an absolute minimum.
Rock sizes to be laid to allow for close bonding.
All sharp faces to be chamfered leaving no machine markings and to replicate natural edge.
Where a retaining rock wall is to be used for seating, grout between rocks should be smooth and level.
Where a free-standing rock wall is to be used for seating purposes, coping material should be smooth and near level.
The top of wall must be sealed to ensure no moisture can seep into the wall and diminish structural strength.
Fixings are to be stainless steel.
Walls for seating should be between 450 mm and 520 mm high for adults.
It is essential that the correct mix of mortar is used to prevent detachment of stones and rocks.
Construction and materials are to meet the following:
Walls over 1.0 m high are to be designed by a suitably qualified engineer.
A masonry block wall is built from individual units laid in and bound together by mortar.
The term masonry refers to the units themselves.
The term render refers to the plaster applied to the masonry wall.
Core filled masonry block walls are to have a footing which is suitable for the site soil conditions and designed by a suitably qualified engineer.
Core filled masonry blocks are suitable as a base material on which to install painted render or tiles.
Masonry wall facings and capping are to be selected for a consistent surface finish.
Where a masonry wall is to be used for seating purposes, coping material should be smooth and near level.
Where a masonry wall is to be used as a memorial wall, wall facing material should be smooth and symmetrical to facilitate fixing of plaques and badges.
Rendered masonry retaining wall with tiled capping
Construction and materials are to meet the following:
Walls over 1.0 m high to be designed by a suitably qualified engineer
Signage walls create a backdrop against which lettering is displayed, such as at a community sporting precinct, or an entry statement to a suburb.
Most materials are suitable for signage walls however select robust materials and finishes which minimise cost implications incurred with ongoing maintenance regimes.
Apply place-making principles to ensure the essence of the area is captured and represented.
Entry walls with electricals housed inside (i.e. for lighting), must provide maintenance access for in-situ repairs
Spectral reflection (the reflection of a beam of light from a mirror like surface) should be considered when selecting materials such as polished stainless steel for lettering on any signage wall which can to be viewed from the road. See Manual of Uniform traffic Control Devices (MUTCD).
Timber is NOT a Council preferred material due to ongoing maintenance cost and vulnerability to white ants and weathering.
Community centre signage wall
Entry statement wall
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Sunshine Coast Open Space Landscape Infrastructure Manual (LIM) DISCLAIMER
Disclaimer
Information contained in this document may change without notice and you should use the current material available from Council’s website and not rely on material previously printed or stored by you.
All figures and diagrams are intended to be used as an aid to design and include Council’s preferred elements but they are not intended to be prescriptive and may need to be varied as dictated by site specific factors. While Council has exercised reasonable care in preparing this document, it does not warrant or represent that it is accurate or complete. The Council will not accept responsibility for any loss, damage, cost or expense that you may incur as a result of the use of or reliance upon any material contained in this document.
This document is produced to convey general information and is not intended to constitute advice whether professional or legal. Any reference to legislation in this document is not an interpretation of the law. It is to be used as a guide only. Consult relevant authority websites for current documents, revisions and amendments.
Where a particular product or supplier is profiled in this document, Council is NOT nominating this product or supplier as the selected choice. Product/supplier information has been provided to allow users to source products which contain the correct elements required for Council embellishments. Each product profiled states ‘or equivalent’ which means that different products may be supplied provided they satisfy the identified performance criteria, recommended standards, equal access guidance and product specifications.
Product design, manufacture and installation requires appropriately qualified people to provide site specific solutions to ensure the embellishment is appropriately adapted to local conditions and data.
This document does not override requirements stipulated in a development approval. Project specific variations may be appropriate as a result of site, environmental or other constraints. Any variations to these standards must be approved in writing by council prior to commencement of variation works. Components of this document may be used within a contract document but users should undertake their own investigations to confirm the information is suitable for this purpose.
Drawings contained in this document are NOT FOR CONSTRUCTION.
Details in this document are deemed to be the minimum standard and the user may wish to apply a higher standard subject to approval by council.
Acknowledgements
Council wishes to thank all contributors and stakeholders involved in the development of this document.
Copyright
Sunshine Coast Regional Council (Council) supports and encourages the distribution of its material however, copyright protects this document. Council has no objection to this material being reproduced but only if council is recognised as the owner of the copyright and this material remains unaltered.
