Concrete
Concrete is used more than any other man-made material in the world as of 2006; about 7.5 cubic kilometers of concrete are made each year more than one cubic meter for every person on Earth.
It vastly used in facades because of its architectural strengths and durability, it with stands a enormous amounts of pressure.
In major construction projects like high rise buildings precast concrete is used where concrete is cast in a reusable mould or “form” which is then cured in a controlled environment, transported to the construction site and lifted into place.
Wood
There are many wood cladding materials such as siding and shingles that have been durable enough to last a long time although there is no doubt that the desire on the part of building owners to keep exterior maintenance to a minimum has resulted in a decrease in the use of wood as an exterior cladding materials
The properties that make wood such a versatile material, such as its ease of workability and its appearance qualities, are also applicable to cladding.
Specialty wood manufacturers have been developing wood cladding products which drastically reduce maintenance requirements which brings back the desire for wood cladding.
Aluminium
Aluminium cladding systems are designed to combine the best of two materials; plastic inside and aluminium outside In addition to this it opens up an unlimited amount of colours.
Since aluminium cladding can be finished in any colour, anodised, film coated, power coated wood look or painted in special colours using modern coating methods.
Stone
Stone curtain walls are conventionally small cut stone set in mortar and are supported by attachments to a back up masonry wall, Slabs of stone with greater surface area may be fastened to framed buildings in several different ways.
Stone panels mounted on a steel sub frame the vertical members of the sub frame are attached to the frame of the building.
This structure transmits the wind and gravity from the stone facing to the supporting structure of the building.
Glass
Many of the world’s major cities and urban business developments are dominated by prestige buildings utilizing glass curtain walling technology to form the outer building envelope.
Curtain walling systems comprise aluminium extruded box sections designed with gaskets to take glass panels and provide a completely impervious facade.
The basic design concept is to clearly distinguish between the functions of the glass and the wind trusses.
The dead load of the glass is transferred to the top of the wall by tension rods that support star-shaped glass connectors the trusses are distinct from the glass.
Link struts are pinned at one end to the star shaped glass connectors and at the other end to the wind trusses the strut transfers wind loads acting on the glass to the truss through axial tension and compression.
Brick
A brick front wall must be constructed properly to secure it to the building and to ensure that any moisture penetrating the brick can escape Brick veneer cladding is used on over 40% of all new homes.
The 40mm cavity required for brick veneer makes it the most forgiving cladding option in regards to potential disasters or weather-tightness problems.
Spanwall
Spanwall’s range of architectural wall cladding systems has an inherent flexibility which allows the company to remain design orientated and to provide its customers with cost effective solutions
Spanwall offer lightweight curtain wall cladding systems which integrate easily with doors, glazing and louvers to create a total building facade.
They are ideally suited for the developments of industrial, leisure, retail, commercial or high technology structures, and for the refurbishment of existing buildings.
Structural integrity and durability
Precast concrete
The main benefits of precast concrete over other cladding materials are its good strength to weight ratio, its mobility and because it is a non-combustible material, fire performance.
It is a very durable material and can have range of finishes depending on the method of production.
The there main advantages of using precast concrete against situ concrete are:
- Speed of erection
- Freedom from shuttering support on site
- Better quality and variety of surface finish because panels are manufactured in controlled factory situations
Glass
Glass is used widely in construction because of it visual aesthetics and durable material which is flexible and manageable material.
The structural integrity reflects in this transparent material which is visually pleasing.
Glass is a very strong material and can be produced to with stand a lot of weight it is very durable as in construction of the Gurkin tower in London which forms the shape of a Gurkin and is totally covered in glass.
Glass in construction does not take the weight of the building which would make it deform and start cracking.
Curtain walling glazing system are used which may be defined as a non-load bearing wall, usually suspended in front of a structural frame, their own dead weight and wind loadings being transferred to the structural frame through anchorage points.
Usually this consists of a rectangular grid of vertical or horizontal framing with infill panels of glass or other light weight panel.
This type of system means that glass does not have to take the load of the building.
Construction methods
Offsite production
Precast concrete is a form of construction, where concrete is cast in a reusable mould or “form” which is then cured in a controlled environment, transported to the construction site and lifted into place.
In contrast, standard concrete is poured into site specific forms and cured on site. Precast stone is distinguished from precast concrete by using a fine aggregate in the mixture so the final product approaches the appearance of naturally occurring rock or stone.
Glass fibre reinforced cement
Glass- fibre reinforced cement is a composite material consisting of ordinary Portland cement, silica sand and water, mixed with alkali-resistant glass fibres.
The ultimate strength of glass -fibre reinforced cement (GRC) is essentially determined by the presence of the fibres, and is therefore dependent upon through glass content.
The glass content controls the maximum loading that the material can withstand the impact performance and durability of the composite.
Process methods for the fabrications of GRC components are spray and premix.
Premix processes are those where the constituents are mixed together into a paste and subsequently formed by castings, press moulding or slip forming.
The three ways of spraying GRC are:
- Manual Spray-
- Mechanized spray
- Spray – dewater process
Span wall
Spanwall offer lightweight curtain wall cladding systems which integrate easily with doors, glazing and louvers to create a total building facade.
Spanwall is ideally suited for the developments of industrial, leisure, retail, commercial or high technology structures, and for the refurbishment of existing buildings.
Span wall is manufactured of site is developed by spanwall specialist in controlled environments.
Once complete it is transported to the construction site to be cladded to the existing structure
The main benefits from using more off-site production on a project are:
- improved predictability resulting from more reliable
- call-off of products and components, and shorter
- lead times
- improved product reliability
- improved quality
- increased efficiency
- improvements to systems/processes
- lower costs
- increased social and environmental benefits
- (reduced waste, more scope for recycling materials)
- ease of maintenance
The main benefits from preassembly are:
- enhanced quality
- lower costs
- increased efficiency and speed
- improved predictability
- increased social and environmental benefits (safer
- and healthier working environment)
- ease of maintenance and replacement
- The maximum benefits arise when standardisation and
Preassembly techniques are applied together
Glazing
In part N of the building regulations the requirement for safe access for cleaning windows etc states.
N4: Provision shall be made for any window, skylights, or any other transparent walls, ceailings or roofs to be safely accessible where there is a danger of falling more than 2 meters.
Quality of construction building fabric
Part L2A of the building regulations states the fabric of should be constructed to a reasonable quality so that:
A: The insulation is reasonably continuous over the whole building envelope.
B: The air permeability is within reasonable limits
Continuity of insulation part L of building regulations
The building fabric should be constructed so that there are no reasonably avoidable thermal bridges in the insulation layers caused by gaps with the various elements.
And also at the joints between the elements and at the edges of elements such as those around windows.
Resistance to the passage of sound Part E
Part E states that there should be adequate protection against sound travelling from other parts of the building and adjoining buildings.
Dwellings, flats, and rooms for residential purposes shall be designed and constructed in such a way that they provide resistance to sound from other parts of the same buildings.
Framed external walls part C of the building regulations
States any framed external wall will meet the requirement if the cladding is separated from the insulation or sheathing by a vented and drained cavity with a membrane that is vapour open.
But resists the passage of liquid water on the inside of the cavity.
Access and maintenance
Buildings shapes are made in a manner of way these days and access is major issue in buildings.
Buildings across sectors need to be compliant with the Disability Discrimination Act 1995 (DDA) as well as passing health and safety inspections and checks.
It is now the responsibility of all building owners and providers of services, under the DDA, to make sure that any sites they are responsible for are fully accessible to everyone, regardless of disability, gender or age.
DDA compliance is further widened into a statutory duty to make sure that all buildings are accessible and usable under Part M of the Building Regulations (1999).
Everyone – whether residents, workers and visitors – needs to be able to gain access to buildings and to gain access to all relevant areas within buildings to use the available facilities.
It’s important that facilities managers understand that DDA and Part M compliance should only be seen as a starting point, and that ‘full access’ means a lot more than people being able to get through the main entrance doors and to the toilets.
It means everyone, regardless of physical ability, being able to use the premises fully and Full access requirements need to be considered and incorporated into design-and-build budgets for new sites.
Any organisations failing to comply with this statutory duty lays themselves open to be legally challenged on these points.
The government’s Equality and Human Rights Commission, established in October 2007, is the main policing organisation tasked with ensuring that the requirements of the DDA and Part M are fully met.
Proper maintenance, and comprehensive Planned Safety Inspections (PSIs), helps ensure that sites comply with all current legislation, including health and safety regulations and DDA issues as well as helping avoid many costly and time-consuming problems on site.
Under the part N glazing section of building regulations it states that any glazing, windows, roofs which are transparent and are over 2 meters in length should have adequate safety measures for maintenance and cleaning.
This measure should be taken into consideration as most buildings are covered in more glazing these days and adequate provisions should be made in advance to keep in line with the building regulations.
