Masonry Support Systems provide a solution to the movement of brickwork due to factors such as moisture, thermal fluctuation, loading, ground movement and structure settlement.
Structures with brick or stone cladding will usually necessitate the use of a stainless steel support system for the masonry.
Bracket Angle Support System
AnconOptima is unlike welded systems, the brackets and angles are supplied as separate components. This provides greater flexibility in the final fixing position of the brackets and makes the system easier to handle on site. Standard systems are available to support a masonry load of up to 14kN/m. Brackets for these systems are stocked to suit cavities from 60mm to 150mm in 5mm increments. They can be changed on site to allow for cavity variations.
Ancon MDC Systems have welded brackets and are designed to suit specific applications. They are available in various configurations and are ideal for supporting special masonry features. Material content is optimised to ensure the most economic solution is designed.
Continuous Angle Support System
Ancon CFA Systems are mainly used where cavities are small or there is a requirement for the cavity to be closed at the support position.
Design Considerations
Structures with brick or stone cladding will usually necessitate the use of stainless steel support for the masonry over horizontal move- ment joints. Differential movement, corrosion resistance, type of cladding and frame type, all need to be considered.
Differential Movement
The maximum size of a masonry panel should be restricted to limit the effects of differential movement. This is particularly important if clay brickwork is used with concrete blockwork and a concrete frame. The outer leaf of buildings not exceeding four storeys or 12 metres in height, whichever is less, may be uninterrupted for its full height. For other buildings, the outer leaf should be supported at intervals of not more than 9 metres or three storeys, whichever is less, as stated in BS 5628 : Part 1 which, since the withdrawal of this British Standard, remains best practice. To allow for a vertical movement of around 1mm per metre, movement joints are generally positioned at every storey or every second storey. They are also incorporated in many buildings of less than four storeys or 12 metres in height.
Horizontal Movement Joints
The support will be positioned directly over the horizontal movement joint. The joint will often incorporate a compressible filler and should be of sufficient size to allow for expansion of the masonry below and any shrinkage or deflection of the structural frame. The underside of the support system should be positioned around 2mm above the joint to allow for the support leg to settle when supporting the brickwork above. The clear joint below should be at least 10mm where there is a single storey height of brickwork below the support system. Where there are two storeys or more of brickwork below the support sys- tem, the clear joint should be sufficient to accommodate all expected movements. This may result in clear joints in excess of 10mm. Damp-proofing is normally located at the support position. Wall ties should be incorporated within 300mm above and below the support.
Fixing Methods
There are various methods of fixing Ancon Support Systems to the structure. Cast-in channels with ‘T’ bolts or site drilled expan- sion bolts can be used with concrete frames. For steel frames the choice is set screws or Ancon Steelgrip into holes in the steel edge member, or where there is a metal deck floor, Ancon CombiDeck has a horizontal channel that accepts ‘T’ bolts. A range of suitable fixings are available.
AnconOptima
The Industry’s growing emphasis on speed of construction, and the inability of welded bracket support systems to provide sufficient adjustment on site, led Ancon to develop AnconOptima.
AnconOptima is a bracket angle masonry support system. Unlike welded systems, the brackets and angles are supplied as separate components. This provides greater flexibility in the final fixing position of the brackets and makes the system easier to handle and move around site.
Systems comprise laser-cut brackets, two step angles with pre- marked fixing zones and locking wedges to ensure the correct contact is achieved between the two.
AnconOptima Systems can be used with the standard Thermal Break to reduce cold bridging.
Standard Systems
Standard systems, referenced AnconOptima 10, 12 and 14, support a masonry load of up to 10kN, 12kN and 14kN per metre respectively. All components are available from stock.
Brackets are available to suit cavities from 60mm to 150mm and are stocked in 5mm increments. Depending on the fixing type, brackets can be changed on site for one of a different depth to allow for cavity variations. Two brackets of a different depth can be used on the same angle.
The brackets used across the three standard systems are universal. The differing performance of the three systems is generated by the varying length and thickness of the angle and the fixing centres of the brackets.
Standard left-hand and right-hand corners are available.
Not being specific to a particular project, unused components can be moved to another project or, for a small restocking charge, returned to Ancon.
Cavity Variations
The ability of welded bracket support systems to accommodate variations in the line of the structure is limited by the maximum thickness of shims, normally 12mm. Some additional adjustment will be possible by varying the bearing of the brickwork on the support angle but this will be very limited, particularly where pistol bricks are used.
When using a standard AnconOptima system, brackets are available from stock to suit cavities from 60mm to 150mm in 5mm increments. They can be changed on site to allow for variations in the edge beam. Shims can be used for fine adjustments and should never need to be more than 4mm thick.
Vertical Adjustment
Vertical adjustment is achieved by the deep slot in the back of the bracket.
Horizontal Adjustment
AnconOptima angles have a 100mm premarked fixing zone which provides 50mm horizontal adjustment.
If fixing into concrete with expansion bolts, the bracket can be moved to eliminate clashes between the bolts and reinforcing bars. Horizontal adjustment can be increased by fixing the system to an Ancon channel cast into the face of the concrete.
If fixing to steelwork, the brackets can be moved to align with the location of a hole, negating the need for a more expensive horizontal slot to be provided.
Setting Out Of Standard Systems
Unlike bespoke systems, there is no time-consuming setting out of individually referenced components with a standard system to a detailed layout drawing.
Cutting On Site
Standard AnconOptima systems are not designed for specific buildings and certain angles will need to be cut on site to suit the length required. Each angle section must have at least two brackets.
Corners
Standard left-hand and right-hand corners are available. Each corner section requires three brackets in order to achieve the required performance. These sections should never be cut.
Installation
Installation of AnconOptima provides significant time savings over welded support systems. The individual components are easier to move around site, often without hiring crane time. The preferred technique of installers is to level and fix two brackets and simply slide the angle into position. This reduces the time spent tightening and loosening the fixing bolts of a welded bracket system, in order to achieve a level horizontal shelf. Where space limitations prevent the angle from sliding, the brackets can be positioned on the angle and conventionally fixed; the smaller lengths of angle simplify this method of installation. When the brackets and angle are in position a locking wedge is tapped with a hammer through the notches in each bracket. These wedges ensure the correct contact is achieved between angle and brackets. A detailed installation guide is available from Ancon.
Ancdon MDC Bracket Angle Support System
Ancon MDC Bracket Angle Support Systems can carry over 8 metres of brickwork and accommodate any width of cavity from 40mm in its standard form. The brackets are welded to the angle and the material content of both components is optimised to ensure the most economic solution is designed.
Design Variations
The Ancon MDC System can be supplied in a variety of configura- tions to suit particular applications and support special masonry features. The size of the support angle can be varied to suit the thickness and height of the masonry to be carried. Bracket spacing, depth and height are all varied to suit loadings, fixing position and cavity width.
There are several variations of the standard MDC System. MDC/P has the bracket projecting below the structure, MDC/R has a re- versed angle welded to the bracket, and MDC/I is a specially inverted system with the support angle at the top of the bracket. These vari- ations allow the support leg of the angle to be positioned anywhere from the top of the bracket to a position below the bottom of the bracket. Non-standard AnconOptima can also be supplied in these variations.
Soldier courses can be suspended from MDC systems by using stir- rups at 225mm centres. The stirrups fit over the angle and stitching rods span between the stirrups, supporting cored or holed bricks.
The Ancon MDC System can be supplied with extra components to suit the application e.g. closer plates, expanded metal etc.
Adjustment
Adjustment is provided in every direction to allow for tolerance in the structural frame. The serrated and slotted face of the bracket allows for vertical adjustment. Cast-in channel will provide virtually unlimited horizontal adjustment; slotted holes in a steel edge member will offer more limited adjustment. Shims can be included between the bracket and the frame up to a maximum thickness of the outside diameter of the fixing bolt, or 16mm, whichever is less. When used, the 3mm thickness of an Ancon Thermal Break should be taken into account when calculating the maximum shimming allowance for a system.
Extension Plates
As an alternative to shims, Ancon Extension Plates can sometimes be used to increase the bearing for the brickwork. The support leg of the angle must provide a minimum of 52mm bearing for standard single skin brickwork for the entire length of the support. Without this bearing the brickwork may become unstable. This must be checked before work proceeds. The extension plates are pushed onto the leg of the angle with the flat surface on top. They are adjusted until the required amount of extension is achieved, this will be from 5mm to 17mm.
The plates can provide extra bearing but they should not extend more than 20mm from the front of the angle. Extension plates are usually 400mm long and fixed with a nominal gap between the plates of approximately 10mm.
Thermal Breaks
Masonry support systems from Ancon can now be supplied with Thermal Breaks to minimise cold bridging, and improve the energy efficiency of your building project.
Shaped like a standard Ancon key-hole shim, these Thermal Breaks are manufactured from a durable fibre-reinforced thermoset plastic, which has a thermal conductivity of just 0.3W/mK.
Ancon CFA Continious Angle Support System
Ancon CFA Systems can carry over 8 metres of brickwork and ac- commodate various cavity widths. For many applications, particularly where large cavities are involved, the Ancon MDC Support System may prove to be a more economical solution. Continuous angles are more suitable for applications where cavities are small or there is a requirement for the cavity to be closed at the support position. The angles are cold formed and will normally be supplied in lengths of up to 4 metres.
Design Variations
In addition to variations in angle size and thickness, an inverted version, the CFA/I, has the support leg at the top and the fixing slots positioned closer to the corner of the angle.
Steel Frames
Ancon CFA Support Systems can be fixed directly to uncased struc- tural steel frames. Universal beams will require an angle to be welded between the flanges at each bracket position. Horizontal slots should always be provided in the steel edge beam to allow lateral tolerance. The angle will have vertical slots with serrated pads welded to the angle.
The structural edge member must be designed to minimise deflec- tions and accommodate the torsional forces created by the eccentric load from the brickwork, if excessive movement of the support system is to be avoided.
Concrete Frames
The CFA System can be fixed to cast-in channels or with expansion bolts. The support angle will either be provided with horizontal slots to suit AnconLock Toothed Channels or with vertical slots and ser- rated pads to suit continuous channels cast horizontally.
Adjustment
Adjustment is provided in every direction to allow for tolerance in the structural frame. Vertical slots in the angle with serrated pads allow ±25mm adjustment. Horizontal adjustment is virtually unlimited when fixing to a continuous cast-in channel and will depend on the length of the slotted holes in the edge member when fixing to steel. The serrated lips of the AnconLock Channel permit a vertical adjust- ment of up to ±28mm. Slotted holes (18 x 60mm) in the angle allow horizontal adjustment of ±22mm. Shims can be included between the bracket and the frame up to a maximum thickness of the outside diameter of the fixing bolt, or 16mm whichever is less.
Bi-Metallic Contact
Corrosion of the steel frame may be slightly increased where there is direct contact with stainless steel in a damp environment. This will not affect the stainless steel and can be avoided by isolating the two dissimilar metals. This can be achieved by painting the contact area or by incorporating a separating membrane that can be supplied with the Ancon CFA Support System.