Designing with Gabions

Transcription

1 Designing with Gabions Volume 2 A Reference Guide for Architectural Gabion Cladding and Free Standing Walls Registered Office: Unit 5, The Cobden Centre, Folly Brook Road, Emerald Park, Emersons Green, Bristol BS16 7FQ Enviromesh is a trading name of Cerana Limited. Registered in England No

2 Contents CONDITIONS & LIMITATIONS PAGE 1 INTRODUCTION PAGE 2 APPLICATIONS PAGE 3 GABION FILLING MATERIALS PAGES 4-5 GABION SPECIFICATIONS PAGE 6 DESIGN PAGE 7 - Stability requirements - Structural dimensional requirements GABION UNIT SIZES PAGES 8-10 INSTALLATION OF CLADDING PAGES FREE STANDING WALLS PAGES SPECIFICATIONS PAGES gabion 27 system mm / 4.00mm - gabion 27 system mm / 4.00mm - gabion 27 system mm / 5.00mm - gabion 27 system mm / 5.00mm - gabion 27 system - trapezoidal - gabion 39 system mm / 4.00mm - gabion 39 system mm / 5.00mm

3 Conditions & Limitations The copyright, design right or other intellectual property in this guide and the products set out herein shall as between Cerana Limited, trading under the Trade Mark of Enviromesh and any customer or potential customer of Enviromesh be the property of Enviromesh. This publication is intended as a general overview of the subjects dealt with and is not intended and should not be used as a substitute for taking detailed and specific advice in any specific situation. The recommendation and advice given in this booklet is given without liability on the part of Enviromesh or its employees and should not be relied upon for any particular action or inaction. Enviromesh shall not be liable to compensate any other party for any loss, including any consequential loss, arising out of any inaccuracies in or omissions from this guide. It is the responsibility of all parties to satisfy themselves that the designs, calculations and specifications set out in proposals submitted by Enviromesh are correct and no responsibility is accepted by Enviromesh for the accuracy of the designs and specifications included in such proposals. Enviromesh Garner Street Business Park Etruria Stoke-on-Trent Staffordshire ST4 7BH Tel: 0044 (0) Fax: 0044 (0) roger.farmer@enviromeshgabions.com Web: 1

4 Introduction In recent years, architects have shown great interest in gabions as a cladding system for buildings as well as perimeter and sound walling. Various reasons have given rise to this: The quality of welded mesh gabion schemes have improved due to the system of manufacture. Requirements for using recycled fills i.e. crushed concrete, saving on materials for disposal and the reduced costs to that of rock fill. Architects embracing new construction materials and textures. To achieve the required quality of construction, gabions are manufactured from heavier mesh wire diameters and the module/unit sizes are non standard as industry standard size gabions would not necessarily achieve what is required. The design of the systems are generally bespoke as no two buildings are the same. The cladding of buildings can be of a thin veneer, generally 300mm thick secured back to the building. These are supported by wind posts or designed as free standing walls in front of the building. The techniques of design and manufacture are extended to free standing perimeter or sound walling and also as a gabion fencing. 2

5 Applications Structure Types Cladding: Buildings: As a facade: - Thin gabion walls secured back to structural walls or steel frame work. As a column supported facade: - Thin gabion walls part secured to steel framed buildings and supported intermittently with additional columns, where no structural supporting wall is available. Free standing Facade: - Rain screen: - Mass gravity walls designed for stability as for free standing walls Minimum width faced walls, generally 0.152m wide or constructed in panel form and secured as panels to a structural wall or suitable framework. Gabions have previously been used as external and internal structural support walls to buildings. This is a specialist application requiring consideration for design as well as insulation and weatherproofing. Although these type of structure have successfully been built on the project list below, advice should be sought from Enviromesh when considering such schemes. Earth Centre, Doncaster Classroom of the Future, London The Boat House, Tunbridge Wells Free Standing Walls: Stability is achieved by virtue of the mass of the structure. The design is based on wind loadings and any other horizontally applied loads. Their format can be as follows: ` Vertical faced gabion walls Vertical on one face, inclined on other face Inclined on both faces Gabion Fencing: Stability is achieved by post or columns embedded into the gabion. The design is based on wind loadings and any other horizontally applied loads. Their format is normally as follows: Normally vertical on both faces and of a narrow width. 3

6 Gabion Filling Materials Aggregate Types Quarried Stone: This type of fill is the most commonest type of gabion fill used and where available is considered the most practical, both for performance (having good interlock properties) as well as its aesthetics. The gabion fill must be a hard durable non frost susceptible rock. The typical rock fill types are as follows :- Sandstone Limestone Granite Basalt Slate (not soft sandstone that is degradable) (beware of sources of Rag Stone that contain Hassock) (Flat in nature. The dimension can be larger than 200mm in the longest dimension) These rock fill types are either blocky or very angular. Blocky stone is very good for giving a dry stone wall appearance and is normally used when a coursed face is required. Angular fill generally requires more careful placement to give a good dry stone wall appearance. Crushed Concrete: Generally crushed concrete is the cheapest type of gabion fill available. It should be from a structural application and therefore non degradable as well as being free of debris and foreign materials. The grading of the crushed concrete is normally poor and selection of the mesh opening size is critical. The grading of the fill must be greater than the mesh opening size and no greater than 2/3rds the unit width or 200mm whichever is the less. Crushed concrete, generally has rounded edges and requires careful packing, as the interlock in the fill is not as good as an angular rock fill. It is therefore recommendable to specify a 5mm mesh wire diameter for external facings. Flint Reject or Cobblestone: This type of fill is not angular and so has no interlocking properties. It is therefore necessary for the wire diameter of the mesh to be 5mm to limit the amount of deflection of the face mesh. The mesh aperture selected is important in that the grading of fill available must be greater than the mesh openings. The restriction on the maximum size is dependant upon the width of the gabion unit. Normally this type of fill is machined placed with no hand facing (generally considered as a self compacting fill). 4

7 Gabion Filling Materials Aggregates: Aggregate fill is self compacting and is of a small stone size that requires a mesh with a small aperture. The minimum apertures available are 76.2mm x 12.7mm, 50.8mm x 25.4mm or 25.4 x 25.4mm. Therefore aggregates only retained by these meshes can be used. Due to the fluid nature of the fill and wire diameters available, the units may require additional internal mesh diaphragms to limit deflection. These issues should be discussed with Enviromesh prior to design and procuring of materials. Brick Fill: Whole brick should be coursed and must be of an engineering type brick. Whole brick can be used as an un cemented coursed facing with broken brick infill. Whole brick should never be used as the mass fill, as there is potential for arching to occur within the fill resulting in possible settlements and distortion of the facing. Broken or crushed brick again must be of an engineering type brick. The brick is generally machined filled and therefore care must be taken on the mesh opening size as a half brick will not be retained by a standard 76.2mm x 76.2mm mesh. 5

8 Gabion Specifications The specification of gabions is an important factor in ensuring the quality and aesthetic appeal of the installation. Although Galfan (95%Zinc-5%Aluminium) coated mesh is used extensively for normal civil engineering gabion works, it is preferable to use Hot Dip Galvanised after coated mesh in accordance with BS EN ISO The reason for this is that Galfan coated mesh is formed from welding the coated wires, the mesh is then cut after welding. Although this is not detrimental to the corrosion resistance of the mesh, the ends of the cut wire have a surface which rusts giving brown coloured cut ends. In contrast, a panel of mesh cut prior to coating and then Hot Dip Galvanised after manufacture, provides all surfaces and cut ends with a zinc coating to give an aesthetic finish akin to the requirements of the architectural finish. Therefore, where the project (gabion cladding or otherwise) is in close proximity to the building and close visual inspection is possible, then the Hot Dip Galvanised after process for the mesh is the preferred specification. Note: The coating weight of Hot Dip Galvanised wire is greater than that of the Galfan coated wire, resulting in similar durability. Specifications Mesh opening Wire Diameters Hot Dip Galvanised ISO mm x 76.2mm 4.0mm Hot Dip Galvanised ISO mm x 50.8mm 4.0mm Hot Dip Galvanised ISO mm x 76.2mm 5.0mm Hot Dip Galvanised ISO mm x 50.8mm 5.0mm Where the structures are remote from the building, either a Hot Dip Galvanised specification or Galfan specification can be used. Specifications Mesh opening Wire Diameters Galfan 76.2mm x 76.2mm 4.0mm Galfan 76.2mm x 76.2mm 5.0mm Galfan is not generally readily available in a 50.8mm x 50.8mm mesh aperture. Non standard meshes are available in Hot Dip Galvanised coating as well as Stainless Steel. The Architect or Designer should contact Enviromesh to discuss these particular requirements. The cost implications of using Stainless Steel meshes is 3 to 4 times greater than that of Galfan or Hot Dip Galvanised products. 6

9 Design Stability Requirements These types of architectural structures must be designed to withstand all external forces that are present such as:- - Wind loading. - Horizontal forces such as pedestrian barrier loadings (please note that gabions must not generally be considered for vehicular impact loadings). - Vertical loadings. - Earth pressure forces where the structure up to a certain height is acting as as a retaining structure. - Design of any support columns where required. - Design of foundations for support columns where required. - Lintel design for door or window openings. - Foundation requirements. Normally a concrete foundation is recommended as gabions are flexible in nature, therefore any localised settlement will be transformed throughout the structure and is difficult to rectify. Structural Dimensional Requirements Consideration must be given to the overall lengths, widths and heights of structures. Gabions are not like timber, concrete or steel constructions where the tolerances can be accurately specified. Although the mesh is of a fixed dimension. the method of jointing adjacent gabions generally gives rise to an increase in the unit dimensions. This increase is difficult to quantify and may be up to 18mm dependant upon the type of jointing used. This makes it very difficult to design a wall to a specific dimension, especially when there are fixed dimensions between openings. This variation can be accommodated in the method of construction and manufacture of the gabion units. It may be a necessity, that the setting out of the gabions is to be carried out to a certain method to ensure that the system will fit. This is normally determined by Enviromesh when the installation layouts are prepared. 7

10 Gabion Unit Sizes Standard Gabion Units Standard sizes available in Galfan coated wire are as follows:- Cell Sizes: 1m x 1m x 0.5m 1.5m x 1m x 0.5m 2m x 1m x 0.5m 1m x 1m x 1.0m 1.5m x 1m x 1.0m 2m x 1m x 1.0m Gabion units are sub-divided by diaphragms (partitioning panels) in to cells for the integrity of the unit as well as restraint against deformation of the product. Cell sizes are a function the unit length and the mesh aperture size. For unit heights of nominal 1.0m and 0.5m, the unit length is divided into cells as follows for differing mesh sizes: Mesh size Unit length Unit Height Cell Sizes 76.2mm x 76.2mm m or 2 unequal cells 0.991m 0.991m and 1.066m Use of standard units may not be compatible for these types of application. It is recommended that the units be of a bespoke manufacture to address the requirements of the scheme. The product can be sized to any multiple of the mesh opening. For economy of manufacture, there are specific unit lengths, dependant on the mesh size that are more appropriate. Bespoke Cladding Units: Sizes can be manufactured to suit required dimensions, but where possible, adoption of standard formats should be used. Optimum Unit Lengths: ` Mesh size Unit lengths 76.2mm x 76.2mm 0.762m or 1.524m 50.8mm x 50.8mm 0.762m or 1.524m Optimum Unit Widths: The unit widths are not so critical. Most widths, as a multiple of the mesh opening are possible with the restriction that the unit width must be at least 2 mesh openings for 76.2mm x 76.2mm mesh and 4 mesh openings for 50.8mm x 50.8mm mesh. Reference should be made to the grading of the fill, such that the cladding width be at a minimum of twice the width of the minimum stone size. 8

11 Gabion Unit Sizes Optimum Cell Heights Unit heights of multiples of the mesh openings are possible, although certain unit heights are preferable. Unit Height Mesh Size Unit Height Mesh Size 0.457m 76.2mm x 76.2mm 0.457m 50.8mm x 50.8mm 0.686m 76.2mm x 76.2mm 0.711m 50.8mm x 50.8mm 0.991m 76.2mm x 76.2mm 1.016m 50.8mm x 50.8mm For constructional reasons in cladding units, 1.0 m high gabions are not recommended for the placing of fill and hand facing the stone. 0.5m high gabions result in higher supply costs and greater installation costs. Gabion 27 system, where the unit heights are 0.686m or 0.711m dependant upon the mesh size, were developed by the writer after extensive investigation in to the design, supply and installation of gabions, both as retaining structures and architectural applications and normally form the basis of our design proposals. The resulting optimum unit sizes for cladding are as follows: Mesh Unit Unit Unit Cell Number of Size Length Height Width Cells (Horizontal x Vertical) 76.2mm x 0.762m 0.686m 0.762m 1 x mm 0.762m 0.991m 0.762m 1 x 1 base cell only 0.762m 1.372m 0.762m 1 x m 2.057m 0.762m 1 x m 0.686m 0.762m 2 x m 0.991m 0.762m 2 x m 1.372m 0.762m 2 x m 2.057m 0.762m 2 x mm x 0.762m 0.711m 0.762m 1 x mm 0.762m 0.991m 0.762m 1 x 1 base cell only 0.762m 1.422m 0.762m 1 x m 2.133m 0.762m 1 x m 0.711m 0.762m 2 x m 0.991m 0.762m 2 x m 1.422m 0.762m 2 x m 2.133m 0.762m 2 x 3 Where the wall height does not suit a combination of the above unit heights, then the top cell can be either reduced in height to fit on site or it may be possible to manufacture a bespoke height unit during production of the products. It is important for aesthetics to maintain coursing throughout the structure. 9

12 Gabion Unit Sizes Trapezoidal Gabions Trapezoidal gabions are manufactured with a mesh face, a base and rear panel with frame supports at intervals along the unit length to provide restraint. The base of the unit above, forms the lid of the unit below. The only unit that has a lid is the very top one. These gabions can be manufactured with both faces inclined or with one face vertical and one face inclined. To determine the inclination angle, the mesh base of the unit above must be a function of the mesh size and the slope length of the face panel should be a multiple of the mesh size with a tolerance of 10mm. The base width, unit height and unit length must also be a function of the mesh size. Typically the inclination of the face is equivalent to the following: 76.2mm mesh 50.8mm mesh 1 or 2 meshes over the unit height 1, 2 or 3 meshes over the unit height For other inclinations greater than the above, please contact Enviromesh direct for advice. Where the structure is adjacent to buildings, then use a Hot Dip Galvanised mesh specification. If the structure is remote from the building, use either Galfan or Hot Dip Galvanised specification. Unit lengths are as follows: 76.2mm mesh 50.8mm mesh 2.057m with frames at 0.686m centres 1.524m with frames at 0.711m centres The ends of the structure are closed with a preformed mesh panel to suit the required trapezoidal configuration. Similarly, preformed panels are used at corners or changes in direction of the structure to give clean joints. Gabion Fence This application is similar to cladding as described, except that the unit is supported by a wind post. Dimensions of units are as for cladding. 10

13 Installation of Cladding Installation Design Methods Cladding systems require some method of securing them in to position to maintain stability. The type of fixing is normally dependant upon the construction of the main structure. Structural Reinforced Concrete Walls:- Units are secured by means of clamp bars or clamp discs located within the gabion. These are anchor bolted through the mesh into the structural wall effectively clamping the mesh to the structural wall. It is recommended that cladding over 3.0m in height has a secondary horizontal support such as a beam or angle section of width equal to 2/3rds of the cladding width. Block Work Walls:- The suitability of fixing back to block work is dependant upon the height of the cladding. Up to one storey, clamping as for structural walls is normally satisfactory, however it is recommended to use resin anchored bolts. ` Where the cladding height is greater than one storey, horizontal support should be provided to take the vertical load of the gabions. This horizontal support must be linked to a concrete or steelwork framework. An alternative is to provide additional support columns or vertical steelwork embedded within the cladding (see details within the next section). A typical method of providing vertical steelwork support is to provide columns at 1.0 to 2.0m intervals to suit the gabion unit lengths. Further columns may be required for openings. The columns are either founded in concrete or bolted into a concrete foundation Where it is not practical to provide column support bolted to or embedded in the foundation, a vertical angle section restrained at floor beam levels may be installed instead with the gabion being secured by a clamp bar bolted to the angle section. Additional steelwork can be used to offset the vertical angle section to create the void for membranes and /or insulation in the cavity wall construction. 11

14 UNIT LENGTH This drawing is the copyright of Cerana Limited (ENVIROMESH), no unauthorised copying is permitted without the permission of Cerana Limite(ENVIROMESH) The design and specifications of gabions and associated materials are limited to materials sourced from Cerana Ltd(ENVIROMESH) CLAMP BARS WITH 3 NUMBER BOLT FIXINGS ARE TO BE LOCATED EVERY OTHER CELL VERTICALLY AND IN EVERY UNIT LONGITUDINALLY. SUPPORT FRAMES OR MESH DIAPHRAGMS STRUCTURAL WALL GABION CLADDING UNITS CLAMP BAR ARRANGEMENT FOR GABION CLADDING GABION 27 CLADDING SYSTEM - WELDED MESH GABIONS FORMED FROM HOT DIP GALVANISED MESH TO BS EN ISO mm x76.2mm OR 50.8mm x 50.8mm IN 4mm OR 5mm DIAMETER WIRE TO THE FACE, BASE, LID AND HORIZONTAL DIAPHRAGMS. VERTICAL DIAPHRAGMS CAN BE FORMED FROM MESH OR FRAMES: VERTICAL DIAPHRAGM MESH SPECIFICATION IS AS FOR THE PRINCIPLE PANELS. INTERMEDIATE FRAMES FORMED FROM HOT DIP GALVANISED WIRE TO BS EN ISO mm DIAMETER. VERTICAL SPACING OF THE CROSS BARS IS TO SUIT THE MESH APERTURE AND UNIT HEIGHT, BUT NOT EXCEEDING 0.25m. END PANELS ARE SUPPLIED TO CLOSE OFF THE END RUN OF GABIONS. DRAWN RDF SCALE NOT TO SCALE REVISIONS PROJECT TITLE CLAMP BAR FIXING PROJECT NUMBER CLADDING Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0)

15 UNIT LENGTH This drawing is the copyright of Cerana Limited (ENVIROMESH), no unauthorised copying is permitted without the permission of Cerana Limite(ENVIROMESH) The design and specifications of gabions and associated materials are limited to materials sourced from Cerana Ltd(ENVIROMESH) CLAMP DISCS EVERY OTHER CELL WITHIN UNIT AS BELOW. EACH OF THE END CELLS SHOUL BE CLAMPED SUPPORT FRAMES OR MESH DIAPHRAGMS STRUCTURAL WALL GABION CLADDING UNITS CLAMP DISC ARRANGEMENT FOR GABION CLADDING GABION 27 CLADDING SYSTEM - WELDED MESH GABIONS FORMED FROM HOT DIP GALVANISED MESH TO BS EN ISO mm x76.2mm OR 50.8mm x 50.8mm IN 4mm OR 5mm DIAMETER WIRE TO THE FACE, BASE, LID AND HORIZONTAL DIAPHRAGMS. VERTICAL DIAPHRAGMS CAN BE FORMED FROM MESH OR FRAMES: VERTICAL DIAPHRAGM MESH SPECIFICATION IS AS FOR THE PRINCIPLE PANELS. INTERMEDIATE FRAMES FORMED FROM HOT DIP GALVANISED WIRE TO BS EN ISO mm DIAMETER. VERTICAL SPACING OF THE CROSS BARS IS TO SUIT THE MESH APERTURE AND UNIT HEIGHT, BUT NOT EXCEEDING 0.25m. END PANELS ARE SUPPLIED TO CLOSE OFF THE END RUN OF GABIONS. DRAWN RDF SCALE NOT TO SCALE REVISIONS PROJECT TITLE CLAMP DISC ARRANGEMENT PROJECT NUMBER CLAMPS Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0)

16 This drawing is the copyright of Cerana Limited (ENVIROMESH), no unauthorised copying is permitted without the permission of Cerana Limite(ENVIROMESH) The design and specifications of gabions and associated materials are limited to materials sourced from Cerana Ltd(ENVIROMESH) SECTION THROUGH A WALL WITH A GABION OUTER LEAF AND BLOCKWORK INNER LEAF 0.762m TYP. B 0.3m ONE MESH VOID WITHIN CLADDING MEMBRANE PROTECTED WITH GEOTEXTILE BLOCKWORK unit cell height 0.686m for 76.2mm mesh 0.711m for 50.8mm mesh B 0.383m SECTION THROUGH BB FOR STABILITY OF THE CLADDING, IT MUST BE SECURED BACK TO THE BUILDING. FOR BLOCK WORK WALLS THE MAXIMUM HEIGHT OF CLADDING SHOULD BE 2M. IF THE HEIGHT EXCEEDS THIS, THEN SUPPORT MEMBERS WILL BE REQUIRED WITHIN THE GABION. DRAWN RDF SCALE NOT TO SCALE REVISIONS PROJECT TITLE CLADDING TO BLOCKWORK PROJECT NUMBER CLADDING Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0)

17 This drawing is the copyright of Cerana Limited (ENVIROMESH), no unauthorised copying is permitted without the permission of Cerana Limite(ENVIROMESH) The design and specifications of gabions and associated materials are limited to materials sourced from Cerana Ltd(ENVIROMESH) 0.3m 0.3m STEEL SUPPORT COLUMN WITH BASE PLATE BOLTED TO CONCRETE FOUNDATION. COLUMNS DESIGNED TO RESIST WIND LOADINGS. STEEL SUPPORT COLUMN WITH BASE PLATE BOLTED TO CONCRETE FOUNDATION. COLUMNS DESIGNED TO RESIST WIND LOADINGS. unit cell height 0.686m for 76.2mm mesh 0.711m for 50.8mm mesh POST CAN BE CENTRAL TO THE DEPTH OF THE GABION BUT THE UNIT DEPTH SHOULD BE 200mm GREATER THAN THE POST WIDTH CONCRETE FOUNDATION CONCRETE FOUNDATION SUPPORT COLUMN FOR CLADDING TO NON STRUCTURAL WALL. COLUMN SITED TO REAR OF THE UNIT. SUPPORT COLUMN FOR CLADDING TO NON STRUCTURAL WALL. COLUMN SITED CENTRAL TO THE DEPTH OF THE GABION. COLUMN (STEEL COLUMN / MEMBER AS REQUIRED BY DESIGN) CLAMP BAR BOLTED TO COLUMN TO SECURE GABION DETAIL OF CLAMP BAR FIXING GABION TO COLUMN DRAWN RDF SCALE NOT TO SCALE REVISIONS PROJECT TITLE COLUMN SUPPORTED CLADDING PROJECT NUMBER CLADDING Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0)

18 Installation of Cladding Gabion Cladding as an Outer Leaf in Cavity Wall Construction. Gabion units are free draining. When used as an outer leaf to cavity wall constructions, an impermeable membrane is required within the cavity. Where no insulation material is to be provided within the cavity, a suitable membrane can be installed to the inner leaf within the cavity. If insulation material is required within the cavity then a membrane is installed against the rear gabion face. Gabions are manufactured from wire that could potentially penetrate the membrane, therefore a non woven geotextile should be placed between the gabion and the membrane to prevent a puncture occurring. It is also a recommendation that the gabion be manufactured with a narrow cell to the rear of the unit that remains as a void to prevent any sharp edges of the gabion fill or pressure from the fill damaging the membrane or insulation. Where it is decided to use wall ties to link the inner and outer gabion cavity, the tie must be securely fixed to the gabion. Where the ties pass through the membrane, it must be sealed. Independant Gabion Cladding In this form of construction, the gabion cladding is designed to be stable under its own mass i.e. designed as a free standing wall. For economy, the wall is normally tapered with the thinner top of the wall being secured back to the structure. The details for forming cavity construction are as above. 16

19 This drawing is the copyright of Cerana Limited (ENVIROMESH), no unauthorised copying is permitted without the permission of Cerana Limite(ENVIROMESH) The design and specifications of gabions and associated materials are limited to materials sourced from Cerana Ltd(ENVIROMESH) TOP WIDTH NOTE: IF THE TOP OF THE WALL IS LESS THAN 0.457m WIDE, THEN CLAMP BARS OR CLAMP DISCS ARE REQUIRED TO TIE THE GABION BACK TO THE STRUCTURE. unit cell height 0.686m for 76.2mm mesh 0.711m for 50.8mm mesh CONCRETE FOOTING BASE WIDTH FREE STANDING WALLS ARE TO BE DESIGNED AS MASS GRAVITY WALLS TO RESIST WIND LOADINGS TOP WIDTH NOTE: IF THE TOP OF THE WALL IS LESS THAN 0.457m WIDE, THEN CLAMP BARS OR CLAMP DISCS ARE REQUIRED TO TIE THE GABION BACK TO THE STRUCTURE. NON WOVEN GEOTEXTILE / IMPERMEABLE MEMBRANE SECONDARY CELL ONE MESH WIDE UNFILLED AS VOID unit cell height 0.686m for 76.2mm mesh 0.711m for 50.8mm mesh BASE WIDTH FREE STANDING WALLS WHERE REQUIRED ARE TO HAVE AN IMPERMEABLE BARRIER BETWEEN THE GABION AND THE STRUCTURE. THE GABION CLADDING IS TO BE DESIGNED AS A MASS GRAVITY WALL TO RESIST WIND LOADINGS. DRAWN RDF SCALE NOT TO SCALE REVISIONS PROJECT TITLE INDEPENDANT CLADDING WALLS PROJECT NUMBER CLADDING Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0)

20 Installation of Cladding Doors, Window Openings and Services Where openings within the cladding system are required, a suitable lintel must be placed above the opening to support any vertical loads above (the gabion density is approximately 1.7 tonnes/cum). The lintel on thin vertical claddings will normally require some form of steelwork support, whereas on a tapered wall the lintel is supported on a concrete pad within a cell at least 0.3m from the opening. The lintel must be set 10mm above the soffit of the opening, so that no vertical load is transferred to the vertical side panels of the openings. The lintel is normally of a width of 75mm less than the cladding depth to allow for a face stone within the baskets to hide the lintel. Door jams can be secured to vertical steelwork set within the gabion. Box outs can also be created where required. This is achieved by inserting suitable panels within the gabion to form a box cell of width and height greater than the box out required. The face and / or rear mesh within the box out is then cut away. Where services are required to pass through the wall, this can be achieved by forming box outs as above or within a conduit sleeve set within the gabion. 18

21 This drawing is the copyright of Cerana Limited (ENVIROMESH), no unauthorised copying is permitted without the permission of Cerana Limite(ENVIROMESH) The design and specifications of gabions and associated materials are limited to materials sourced from Cerana Ltd(ENVIROMESH) SECTION THROUGH WALL WITH GABION OUTER LEAF AND BLOCKWORK INNER LEAF 0.762m typical B 0.3m ONE MESH VOID WITHIN CLADDING. INNER FACE TO BE LINED WITH AN IMPERMEABLE MEMBRANE, PROTECTED BY A NON WOVEN GEOTEXTILE. LINTEL LINTEL TO BE SET 10mm ABOVE THE UNDERSIDE OF THE GABION FOR ONE CELL EITHER SIDE OF THE OPENING. LINTEL STEEL COLUMN SUPPORT unit cell height 0.686m for 76.2mm mesh 0.711m for 50.8mm mesh B CELLS EITHER SIDE OF OPENING, 300MM WIDE ROCKFILLED TO FULL DEPTH. SECTION THROUGH BB 0.762m typical A UNIT CAN BE INCREASED IN DEPTH TO INFILL BACK TO THE BLOCK WORK. 0.3m ONE MESH VOID WITHIN CLADDING. INNER FACE TO BE LINED WITH AN IMPERMEABLE MEMBRANE, PROTECTED BY A NON WOVEN GEOTEXTILE. LINTEL PAD STONE LINTEL PAD STONE PAD STONE TO BE SET 10mm ABOVE THE UNDERSIDE OF THE GABION FOR ONE CELL EITHER SIDE OF THE OPENING. unit cell height 0.686m for 76.2mm mesh 0.711m for 50.8mm mesh A CELLS EITHER SIDE OF OPENING 300MM WIDE ROCKFILLED TO FULL DEPTH UNIT CAN BE INCREASED IN DEPTH TO CLOSE BACK TO BLOCK WORK SECTION THROUGH AA GABION 27 CLADDING SYSTEM - WELDED MESH GABIONS FORMED FROM HOT DIP GALVANISED MESH TO BS EN ISO mm x76.2mm OR 50.8mm x 50.8mm IN 4mm OR 5mm DIAMETER WIRE TO THE FACE, BASE, LID AND HORIZONTAL DIAPHRAGMS. VERTICAL DIAPHRAGMS CAN BE FORMED FROM MESH OR FRAMES: VERTICAL DIAPHRAGM MESH SPECIFICATION IS AS FOR THE PRINCIPLE PANELS. INTERMEDIATE FRAMES FORMED FROM HOT DIP GALVANISED WIRE TO BS EN ISO mm DIAMETER. VERTICAL SPACING OF THE CROSS BARS IS TO SUIT THE MESH APERTURE AND UNIT HEIGHT, BUT NOT EXCEEDING 0.25m. END PANELS ARE SUPPLIED TO CLOSE OFF THE END RUN OF GABIONS. DRAWN RDF SCALE NOT TO SCALE REVISIONS DOOR AND WINDOW OPENINGS PROJECT NUMBER CLADDING Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0)

22 This drawing is the copyright of Cerana Limited (ENVIROMESH), no unauthorised copying is permitted without the permission of Cerana Limite(ENVIROMESH) The design and specifications of gabions and associated materials are limited to materials sourced from Cerana Ltd(ENVIROMESH) 2 X INTERMEDIATE LIDS AND FACE PANELS SUPPLIED LOOSE FOR SITE FITTING. LID VERTICAL DIAPHRAGM FRAMES OR MESH PANELS REAR PANEL VERTICAL END PANELS FIRST LIFT FACE PANEL BASE INTERMEDIATE PANEL SET INTO POSITION ON SITE SCHEMATIC DRAWING OF UNIT MANUFACTURE CLADDING UNITS ARE MANUFACTURED IN MODULE LENGTHS OF 0.762m OR 1.524m. ALL VERTICAL JOINTS ARE TO BE HELICALLED. RECOMMENDED MESH SPECIFICATION IS HOT DIP GALVANISED COATED IN 4mm WIRE DIAMETER. INTERMEDIATE LIFTS ARE NORMALLY EQUAL TO THE MODULE LENGTH TO GIVE A SQUARE PATTERN ON THE FACE. WHERE THE CLADDING HEIGHT IS NOT A MULTIPLE OF THE STANDARD CELL HEIGHT, THE BASE CELL HEIGHT CAN BE INCREASED UP TO 0.991m OR THE TOP CELL REDUCED TO MINIMUM OF 0.152m UNIT DEPTHS ARE TO BE A MULTIPLE OF THE MESH SIZE. DRAWN RDF SCALE NOT TO SCALE REVISIONS PROJECT TITLE CLADDING UNIT MANUFACTURE PROJECT NUMBER CLADDING Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0)

23 This drawing is the copyright of Cerana Limited (ENVIROMESH), no unauthorised copying is permitted without the permission of Cerana Limite(ENVIROMESH) The design and specifications of gabions and associated materials are limited to materials sourced from Cerana Ltd(ENVIROMESH) INTERMEDIATE LIDS AND FACE PANELS SUPPLIED LOOSE STAGE 1 SECURE GABIONS BACK TO THE STRUCTURE WITH CLAMP BARS OR CLAMP DISCS STAGE 4 FORM BASKET INTO ITS OPEN FRONTED BOX SHAPE AND JOIN TO ADJACENT UNITS ACCORDINGLY USING HELICALS TO ENCOMPASS THE MESH AND FRAMES. INTERMEDIATE LIDS AND FACE PANELS SUPPLIED LOOSE STAGE 2 STAGE 5 ROTATE THE FIRST FACE PANEL INTO POSITION AND HELICAL AND PLACE ROCK FILL INTO THE CELL. WIRE DOWN LID TO CLOSE OFF UNITS NOTES: INTERMEDIATE LIDS AND FACE PANELS SUPPLIED LOOSE A RUN OF UNITS SHOULD BE ASSEMBLED AND FIXED WITH CLAMP BARS OR DISCS TO THE WALL AS PER STAGE 1 A SINGLE HELICAL IS USED TO CONNECT THE ADJACENT FACE PANELS AND THE FRAME FOR EACH LIFT. STAGE 3 INSERT LOOSE INTERMEDIATE LIDS AND FACE PANELS, THEN CONNECT TO THE REAR PANEL AND THE FACE PANEL OF THE CELL BELOW. ROTATE THE FACE PANEL INTO POSITION AND PLACE ROCK FILL INTO THE CELL. DRAWN RDF SCALE NOT TO SCALE REVISIONS PROJECT TITLE CLADDING CONSTRUCTION SEQUENCE PROJECT NUMBER CLADDING Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0)

24 Free Standing Walls Typically free standing gabion walls take one of the following forms: Vertical Walls Gabion modules of uniform width either in the standard Gabion 39 unit sizes or the Gabion 27 system (note:- higher quality and ease of construction is achieved with the Gabion 27 system). Wall heights (nominal) 0.686m, 0.991m and 1.362m in Gabion 27 system x 0.686m wide m to 2.360m in Gabion 27 system x 1.0m wide. Maximum of 2.5m in standard Gabion 39 system - 1.0m wide. Trapezoidal walls Walls can either be sloped on one face or both faces. The slope angle is either 1 mesh or 2 meshes in the unit height, on one or both faces. i.e. Gabion 27 system: 9 in 1 (6.35 degrees from vertical) 9 in 2 (12.6 degrees from vertical) Gabion 39 system: 13 in 1 (4.4 degrees from vertical) 13 in 2 (8.75 degrees from vertical) The walls are designed as mass gravity walls against wind loading and earth pressures if the wall is part retaining. The minimum width at the top is normally 0.457m, though this may increase dependant upon the stability. It is possible to have walls part trapezoidal in the upper courses and vertically faced in the lower courses. Gabion Fence This is basically the same as a cladding unit but has a post central to the width of the unit secured to the internal frames normally at a maximum of 3 cell lengths. The support posts can be concreted into the ground at the required intervals and provided with a nominal 200mm depth of concrete foundation. Alternatively, the posts can be bolted down to a ground beam. The concrete foundation is provided to ensure that the gabion fence alignment is linear. If no suitable foundation is provided, differential settlements may occur affecting the wall alignment. 22

25 This drawing is the copyright of Cerana Limited (ENVIROMESH), no unauthorised copying is permitted without the permission of Cerana Limite(ENVIROMESH) The design and specifications of gabions and associated materials are limited to materials sourced from Cerana Ltd(ENVIROMESH) granular or concrete foundation VERTICAL FACE STEPPED WALLS granular or concrete foundation COMBINED VERTICAL AND INCLINED FACED WALLS granular or concrete foundation INCLINED FACED WALLS FREE STANDING MASS GRAVITY GABION WALLS DRAWN RDF SCALE NOT TO SCALE REVISIONS PROJECT TITLE FREESTANDING WALLS PROJECT NUMBER CLADDING Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0)

26 Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0) WELDED MESH GABION SPECIFICATION Gabion 27 Cladding - 4.0mm Wire Diameter Hot Dip Galvanised Gabions shall comply with the following specifications MANUFACTURE: MESH SIZE: Gabions shall be manufactured from a hard drawn steel wire formed into a bi-axial mesh grid by electrically welding the cross wires at every intersection. The weld strength is to be 70% of the ultimate tensile strength of the wire. Gabions are to be factory assembled with stainless steel clips (minimum one every third mesh opening) connecting side panels and diaphragms to the base panel. Units shall be supplied in lengths of 1.52m, with horizontal diaphragms at typical 0.711m lifts and vertical diaphragms at 0.762m intervals. Units shall be designed such that the coursing remains continuous along the length of the structure with modification of the top and lower cells heights as required to accommodate the stepping arrangement of the top of the wall and foundation levels. The unit is to be manufactured such that the maximum height is 2.133m and assembled to allow filling of the unit in lifts of typically 0.711m. The mesh openings shall be square and of a nominal dimension of 50.8mm on the grid. MESH WIRE: The nominal wire diameter shall be 4.0mm all in accordance with BS EN The tensile strength falls within a range of N/mm 2. DEFORMATION CO-EFFICIENT: The maximum deformation coefficient is to be 0.25 for the unsupported mesh facing. CORROSION: Wire shall be Hot Dip Galvanised in accordance with BS EN ISO JOINTING: ROCKFILL: CONSTRUCTION: Gabions shall be provided with Galfan coated (95% Zinc / 5% Aluminium) helicals in 3.0mm wire diameter for vertical joints and lacing wire / helicals for horizontal joints except for the lid which shall be helical jointed. Lacing wire shall be Galfan coated and of a minimum wire diameter of 2.2mm for final jointing. Gabion fill shall be a hard durable and non frost susceptible (rock or stone type) having a minimum dimension not less than the mesh opening and a maximum dimension of 200mm. Units to be secured to the concrete wall with 1500mm x 50mm x 10mm clamp bars galvanised to BS EN ISO1461 bolted to the wall with 4 no. anchor bolts (clamp bars are predrilled with 13mm holes). Clamp bars are to be located at a maximum of 1.4m vertical centres. All rock fill shall be packed tightly to minimize voids and the rockfill on the exposed face of the gabion is to be hand packed. Corner bracing ties 2 per cell installed at mid height across each corner on 0.711m high cells and at 1/3 rd and 2/3 rd height on cells greater than 0.711m in height. Units shall be filled such that the mesh lid bears down onto the rock fill. The lid shall be wired down on all joints and across the diaphragms. SPEC 8: Registered Office: Unit 5, The Cobden Centre, Folly Brook Road, Emerald Park, Emersons Green, Bristol BS16 7FQ Enviromesh is a trading name of Cerana Limited. Registered in England No

27 Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0) WELDED MESH GABION SPECIFICATION Gabion 27 Cladding 4.0mm Wire Diameter Hot Dip Galvanised Gabions shall comply with the following specifications MANUFACTURE: MESH SIZE: Gabions shall be manufactured from a hard drawn steel wire formed into a bi-axial mesh grid by electrically welding the cross wires at every intersection. The weld strength is to be 70% of the ultimate tensile strength of the wire. Gabions are to be factory assembled with stainless steel clips (minimum one every third mesh opening) connecting side panels and diaphragms to the base panel. Units shall be supplied in lengths of 1.52m, with horizontal diaphragms at typical 0.686m lifts and vertical diaphragms at 0.762m intervals. Units shall be designed such that the coursing remains continuous along the length of the structure with modification of the top and lower cells heights as required to accommodate the stepping arrangement of the top of the wall and foundation levels. The unit is to be manufactured such that the maximum height is 2.057m and assembled to allow filling of the unit in lifts of typically 0.686m. The mesh openings shall be square and of a nominal dimension of 76.2mm on the grid. MESH WIRE: The nominal wire diameter shall be 4.0mm all in accordance with BS EN The tensile strength falls within a range of N/mm 2. DEFORMATION CO-EFFICIENT: The maximum deformation coefficient is to be 0.25 for the unsupported mesh facing. CORROSION: Wire shall be Hot Dip Galvanised in accordance with BS EN ISO JOINTING: ROCKFILL: CONSTRUCTION: Gabions shall be provided with Galfan coated (95% Zinc / 5% Aluminium) helicals in 3.0mm wire diameter for vertical joints and lacing wire / helicals for horizontal joints except for the lid which shall be helical jointed. Lacing wire shall be Galfan coated and of a minimum wire diameter of 2.2mm for final jointing. Gabion fill shall be a hard durable and non frost susceptible (rock or stone type) having a minimum dimension not less than the mesh opening and a maximum dimension of 200mm. Units to be secured to the concrete wall with 1500mm x 50mm x 10mm clamp bars galvanised to BS EN ISO1461 bolted to the wall with 4 no. anchor bolts (clamp bars are predrilled with 13mm holes). Clamp bars are to be located at a maximum of 1.4m vertical centres. All rock fill shall be packed tightly to minimize voids and the rockfill on the exposed face of the gabion is to be hand packed. Corner bracing ties 2 per cell installed at mid height across each corner on 0.686m high cells and at 1/3 rd and 2/3 rd height on cells greater than 0.686m in height. Units shall be filled such that the mesh lid bears down onto the rock fill. The lid shall be wired down on all joints and across the diaphragms. SPEC 9: Registered Office: Unit 5, The Cobden Centre, Folly Brook Road, Emerald Park, Emersons Green, Bristol BS16 7FQ Enviromesh is a trading name of Cerana Limited. Registered in England No

28 Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0) WELDED MESH GABION SPECIFICATION Gabion 27 Cladding - 5.0mm Wire Diameter Hot Dip Galvanised Gabions shall comply with the following specifications MANUFACTURE: MESH SIZE: Gabions shall be manufactured from a hard drawn steel wire formed into a bi-axial mesh grid by electrically welding the cross wires at every intersection. The weld strength is to be 70% of the ultimate tensile strength of the wire. Gabions are to be factory assembled with stainless steel clips (minimum one every third mesh opening) connecting side panels and diaphragms to the base panel. Units shall be supplied in lengths of 1.52m, with horizontal diaphragms at typical 0.711m lifts and vertical diaphragms at 0.762m intervals. Units shall be designed such that the coursing remains continuous along the length of the structure with modification of the top and lower cells heights as required to accommodate the stepping arrangement of the top of the wall and foundation levels. The unit is to be manufactured such that the maximum height is 2.133m and assembled to allow filling of the unit in lifts of typically 0.711m. The mesh openings shall be square and of a nominal dimension of 50.8mm on the grid. MESH WIRE: The nominal wire diameter shall be 5.0mm all in accordance with BS EN The tensile strength falls within a range of N/mm 2. DEFORMATION CO-EFFICIENT: The maximum deformation coefficient is to be 0.25 for the unsupported mesh facing. CORROSION: Wire shall be Hot Dip Galvanised in accordance with BS EN ISO JOINTING: ROCKFILL: CONSTRUCTION: SPEC 10: Gabions shall be provided with Galfan coated (95% Zinc / 5% Aluminium) helicals in 3.0mm wire diameter for vertical joints and lacing wire / helicals for horizontal joints except for the lid which shall be helical jointed. Lacing wire shall be Galfan coated and of a minimum wire diameter of 2.2mm for final jointing. Gabion fill shall be a hard durable and non frost susceptible (rock or stone type) having a minimum dimension not less than the mesh opening and a maximum dimension of 200mm. Units to be secured to the concrete wall with 1500mm x 50mm x 10mm clamp bars galvanised to BS EN ISO1461 bolted to the wall with 4 no. anchor bolts (clamp bars are predrilled with 13mm holes). Clamp bars are to be located at a maximum of 1.4m vertical centres. All rock fill shall be packed tightly to minimize voids and the roc kfill on the exposed face of the gabion is to be hand packed. Corner bracing ties 2 per cell installed at mid height across each corner on 0.711m high cells and at 1/3 rd and 2/3 rd height on cells greater than 0.711m in height. Units shall be filled such that the mesh lid bears down onto the rock fill. The lid shall be wired down on all joints and across the diaphragms. Registered Office: Unit 5, The Cobden Centre, Folly Brook Road, Emerald Park, Emersons Green, Bristol BS16 7FQ Enviromesh is a trading name of Cerana Limited. Registered in England No

29 Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0) WELDED MESH GABION SPECIFICATION Gabion 27 Cladding - 5.0mm Wire Diameter Hot Dip Galvanised Gabions shall comply with the following specifications MANUFACTURE: MESH SIZE: MESH WIRE: DEFORMATION CO-EFFICIENT: Gabions shall be manufactured from a hard drawn steel wire formed into a bi-axial mesh grid by electrically welding the cross wires at every intersection. The weld strength is to be 70% of the ultimate tensile strength of the wire. Gabions are to be factory assembled with stainless steel clips (minimum one every third mesh opening) connecting side panels and diaphragms to the base panel. Units shall be supplied in lengths of 1.52m, with horizontal diaphragms at typical 0.686m lifts and vertical diaphragms at 0.762m intervals. Units shall be designed such that the coursing remains continuous along the length of the structure with modification of the top and lower cells heights as required to accommodate the stepping arrangement of the top of the wall and foundation levels. The unit is to be manufactured such that the maximum height is 2.057m and assembled to allow filling of the unit in lifts of typically 0.686m. The mesh openings shall be square and of a nominal dimension of 76.2mm on the grid. The nominal wire diameter shall be 5.0mm for exposed all in accordance with BS EN The tensile strength falls within a range of N/mm 2. The maximum deformation coefficient is to be 0.25 for the unsupported mesh facing. CORROSION: Wire shall be Hot Dip Galvanised in accordance with BS EN ISO JOINTING: ROCKFILL: CONSTRUCTION: SPEC 11: Gabions shall be provided with Galfan coated (95% Zinc / 5% Aluminium) helicals in 3.0mm wire diameter for vertical joints and lacing wire / helicals for horizontal joints except for the lid which shall be helical jointed. Lacing wire shall be Galfan coated and of a minimum wire diameter of 2.2mm for final jointing. Gabion fill shall be a hard durable and non frost susceptible (rock or stone type) having a minimum dimension not less than the mesh opening and a maximum dimension of 200mm. Units to be secured to the concrete wall with 1500mm x 50mm x 10mm clamp bars galvanised to BS EN ISO1461 bolted to the wall with 4 no. anchor bolts (clamp bars are predrilled with 13mm holes). Clamp bars are to be located at a maximum of 1.4m vertical centres. All rock fill shall be packed tightly to minimize voids and the rock fill on the exposed face of the gabion is to be hand packed. Corner bracing ties 2 per cell installed at mid height across each corner on 0.686m high cells and at 1/3 rd and 2/3 rd height on cells greater than 0.686m in height. Units shall be filled such that the mesh lid bears down onto the rock fill. The lid shall be wired down on all joints and across the diaphragms. Registered Office: Unit 5, The Cobden Centre, Folly Brook Road, Emerald Park, Emersons Green, Bristol BS16 7FQ Enviromesh is a trading name of Cerana Limited. Registered in England No

30 Garner Street Business Park, Etruria, Stoke-on-Trent, Staffordshire, ST4 7BH Tel: +44 (0) Fax: +44 (0) WELDED MESH GABION SPECIFICATION Trapezoidal Gabion 27 System 3.00mm / 4.0mm Wire Diameter Hot Dip Galvanised Gabions shall comply with the following specifications MANUFACTURE: MESH SIZE: MESH WIRE: FRAME WIRE: CORROSION: JOINTING: ROCKFILL: CONSTRUCTION: Gabions shall be manufactured from a hard drawn steel wire formed into a bi-axial mesh grid by electrically welding the cross wires at every intersection. The weld strength is to be 70% of the ultimate tensile strength of the wire. Gabions are to be factory assembled with stainless steel clips (minimum one every third mesh opening) connecting face and rear panels to the base panel and the lid to the face panel where required. Welded A-Frames to a maximum width of 1.0m are to be manufactured to the required shape (one frame per 0.686m cell to be provided for installation on site). The mesh openings shall be square and of a nominal dimension of 76.2mm on the grid. The nominal wire diameter shall be 3.0mm for the base, ends, lids and diaphragms where required and 4.0mm for the front and rear panels all in accordance with BS EN The tensile strength falls within a range of N/mm 2. The A-Frames are to be manufactured from 10mm mild steel bar. All Wires for the mesh and A-Frames shall be Hot Dip Galvanised in accordance with BS EN ISO Gabions shall be provided with Galfan coated (95% Zinc / 5% Aluminium) helicals manufactured from 3.0mm wire diameter and Galfan coated lacing wire manufactured from a minimum wire diameter of 2.0mm for final jointing. Gabion fill shall be a hard durable and non frost susceptible (rock or stone type) having a minimum dimension not less than the mesh opening and a maximum dimension of 200mm. All rock fill shall be packed tightly to minimize voids and the rock fill on the exposed face of the gabions is to be hand packed. Internal windlass bracing ties are to be positioned at 1 per face cell at midpoint on 0.686m high units and at mid point and third heights on 1.0m high units. Adjacent units are to be jointed with full-length helicals on all vertical joints and laced horizontally with lacing wire through every mesh space at the front and rear of each course. Units shall be filled such that the mesh base of the unit above bears down onto the rock fill. The lid shall be wired down on all joints and across the diaphragms. SPEC12: Registered Office: Unit 5, The Cobden Centre, Folly Brook Road, Emerald Park, Emersons Green, Bristol BS16 7FQ Enviromesh is a trading name of Cerana Limited. Registered in England No