Building Technology - selecting materials for floors and walls

by calum_82 (student)

University Degree Architecture, Building and Planning

Calum Stringer 0600532

QUESTION 1

Steel stair construction has been selected. Provide a drawing of the section of one flight of stairs to Stairs 3, including the landings, to an appropriate scale to fit onto an A4 sheet.

(30 marks)

See Attached Plan

QUESTION 2

Describe the performance requirements of platform flooring in the offices and select a suitable platform floor, with reasoning, for the offices. Provide a sketch to show the section of the platform floor with the floor and finish.

(35 marks)

A raised access flooring system is defined in Platform Floors (Raised Access Floors) - Performance Specification as “load bearing fixed or removable panels supported by adjustable pedestals to provide an under floor space for the housing and distribution of services” (PSA Specialist Services, 1992).

The functional requirements of the office floor structure will depend on whether it is ground or an upper floor. The floor is required to have sufficient load bearing capabilities without causing any undue deflection, sufficient fire resistance requirements for the building, thermal capabilities, adequate sound insulation, and for the (ground floor) damp proofing.

Performance factors will include things such as delivery and construction time, the availability of labour, the compatibility of the office’s construction, requirements for the layout and spacing, its cost and the fire legislation requirements.

The offices will have high requirements for platform flooring because of its many benefits, the platform floor creates a void under floor level that can allow building services to be installed or modified to the required areas. This can include the following: electrical, data and telecom cabling, heating or ventilation and its control, fire suppression and detection, security and water and drainage pipework. By using the platform flooring it allows quick and easy access to these services for maintenance purposes and enables office layout changes.

The two categories of platform flooring systems are full and partial. Where the decked raised floor is continuously used but for only part of the floor, generally where cable are initially required, this is the partial access floor system. It is formed with individual boards or panels which are supported on pedestals and joists to a suitably determined height. These boards or panels are permanently fixed to the support therefore access to the void under the sub floor is restricted to areas of removable flooring or hatches.

Where the continuously decked raised floor is formed with separate panels this is known as full access floor systems which are supported on pedestals to a determined height. The panels are made to a standard size and are removable and completely exchangeable within the installed system.

The two types of platform flooring that I have looked into are the gravity laid and screw down systems with either a flooring cover constructed out of Calcium Sulphate Panels or Steel Encapsulated Wood Core Panels.

Calcium Sulphate core is characteristically less vulnerable to variations in temperature and humidity than products with wooden cores. This offers greater flexibility with installation and greater lateral stability at higher floor heights with the corner lock panel system. There are many finishes available to this type of material, for example carpet, PVC and integral HPL. It has a high load rolling capacity, good acoustic properties, is non-combustible, and the edging has a protective trim. It can be used in various locations with different types of traffic, including general and high density office areas and plant and server rooms.

Steel Encapsulated ...

This is a preview of the whole essay

Steel Encapsulated Wood Core panel is designed with a double folded, interlocking steel sheet. This creates an enhanced strength product. Its flexibility to be cut to fit enables greater ease with installations without the use of specialist machinery. There is greater lateral stability at higher floor heights with the corner lock panel system. It can be used in various locations with different types of traffic, including general and high density office areas and plant and server rooms.

Depending on the intensity and weight of traffic it is necessary to consider the durability of the flooring and also the load of stationary furniture and equipment.

The floor finish in the office must be able to provide a comfortable and thermally efficient surface which is non-slip to provide a finish which is convenient and suitable and minimises any potential slip and trip hazards.

Carpet can be effective whilst being functional. A quality carpet will be more durable and last longer.
Carpet tiles can easily be replaced, and are quicker and more straightforward to install than carpet.
Vinyl has excellent water proof qualities and at the right quality can be very durable.
Tiles are durable, hard wearing and often easy to clean,
Polished Timber is less well suited to offices and work areas as floorboards can be noisy and have poor acoustic properties.

I have chosen to use the Calcium Sulphate Core panelling with a floor covering of carpet. This will provide a sufficient load bearing capacity for the flooring type and number of staff and finish which is durable, cost effective, easily replaceable and be aesthetically pleasing.

QUESTION 3

Explain the issues to be considered when selecting a suitable finish for each of the following in the ground-floor office:

ceiling

walls.

Select a suitable finish for each of these, with justification, and include sketches and a description of the construction of the finishes.

(35 marks)

CEILINGS

The issues that need to be addressed when in looking into installing a suitable ceiling covering will depend upon the usage of the building. As this is an office building I will look at two options which can be used, a smooth plastered finish and a suspended tile grid system.

The requirements of a functional ceiling finish are to protect the structural floor above with a fire resistance element, to be aesthetically pleasing to staff and visitors, to ensure sound transmission is minimised and the acoustic properties are met. The cost and maintenance of the ceiling need to be taken into account in the construction phase and the need for flexibility within the buildings usage.

Plaster is a commonly used form of interior ceiling finishing. There are advantages with this type of finish, such as it can be seen for its durability. When the chemical reaction occurs once water has evaporated, a strong bond is produced. It is generally resistant to knocks and dents and It can be easily installed by a professional contractor. Plaster allows for a clean and smooth finish which can be decorated and aesthetically pleasing. The disadvantages are that if it gets damaged it is not always easily repairable. Plaster can dry out over time, crack and split with movement in the building and requires decoration on a fairly regular basis to maintain looking in good condition. Any piping and wiring that is installed behind plaster ceilings is problematic to change once the ceiling is finished. Wires have to be either pulled through the space behind the ceiling or it has to be completely removed in order for changes to be made and this can lead to significant costs.

A suspended ceiling is hung underneath the structural ceiling. The void space above can be used to conceal wiring, piping, or ductwork. It will consist of a grid of metal channels which is suspended by wires from the structural ceiling. The channels are put together and filled up with lightweight tiles which simply fall into place. The types of tile can vary with the use of different materials such as metal, plastic, wood or mineral fibres. Fixtures and fittings such as lights or HVAC air grilles can be fitted into the same sized spaces. Tiles can be easily cut up and modified to fit into smaller gaps or where smaller objects such as smoke detectors protrude through.

The advantages of a suspended ceiling is that is allows easy access to areas at any time when installing or modifying pipework ducting, wiring or data cabling. Modifications to the ceiling can be carried out where the need to partition areas off or remove the partitioning. It can improve insulation and lower heating running costs. Fire resistance can be met where the ceiling tiles are made from mineral fibre and other fire rated materials. The use of ceilings can Improve acoustics and reduce noise from the floors above as well as providing an aesthetically pleasing view.

The disadvantages of a suspended ceiling are that when panels are removed they can be easily damaged and require replacement. The installation of a suspended ceiling requires a higher building which can increase the construction costs as clearance is essential between any ductwork or pipes and the grid above in order to install light fixtures and the ceiling tiles. Suspended ceilings will tend to show discoloration and stains and sag after a few years of use. Regular maintenance is required to maximise the life span of this type of ceiling which is often costly. The ceilings are not as rigid and sturdy as the typical plastered ceiling and can allow installed fixtures to fall on people beneath them.

It can be seen that although there are disadvantages to installing a suspended ceiling over a plastered finish, it is in my opinion that the advantages of using a suspended grid system far out way the disadvantages and that based in the office environment it allows for easier modification and adaptation.

WALLS

The issues that need to be addressed when in looking into installing a suitable wall covering will depend upon the usage of the building. As this is an office building I will look at which can be used in this particular setting. There are many different types of wall finishes that are used to finish internal walls which include: plaster, wooden cladding, tile cladding, rendered finish, laminate and stone work.

The requirements of internal walls and its functionality will depend upon where the wall is, therefore I have assumed it to be the internal face of the external wall. The cost and maintenance of the ceiling need to be taken into account in the construction phase and the need for flexibility within the buildings usage.

The structure of the wall will need to sufficient enough to carry any loads of the floors above and remain structurally stable and meet the required level of fire protection to satisfy building regulations. If there were partitions then they may require continuation above the suspended ceiling, prevent any water or damp penetration and they should allow sufficient levels of noise control and thermal insulation.

The finishes of the wall will provide a decorative skin to hide building components including the structural frame, ductwork, insulation, wires and pipes.

Plaster is a commonly used form of interior wall finishing. There are advantages with this type of finish such as it can be seen for its durability, when the chemical reaction occurs once water has evaporated produces a strong bond and it is generally resistant to knocks and dents. It can be easily installed by a professional contractor and allows for a clean and smooth finish which can be decorated and aesthetically pleasing.

The disadvantages are that if it gets damaged it is not always easily repairable, it can dry out over time, crack and split with movement in the building. Decoration is required on a fairly regular basis to maintain it looking in good condition. Any piping and wiring that is installed behind plaster ceilings is problematic to change once the ceiling is finished. Wires have to be either pulled through the space behind the ceiling or it has to be completely removed in order for changes to be made and this can lead to significant costs.

Wet Plaster can either be applied as a skim finish on plasterboard or as a cement render undercoat with a skim finish. The advantages are that if correctly installed the finish is nice and clean and ready for decoration. Disadvantages with wet finishes are that it is prone to cracking where drying out and movement occur in the first couple of years of the buildings life and can be labour intensive.

Dry-lining finishes are applied to a board backing. This is then finished by applying filler over nail holes and the joints followed sanding and preparing the surface before decoration. It is less prone to cracking than wet plastering. This finish is similar to painting on lining paper

A tiled wall can be installed where the surface has been prepared properly, is level, dry, clean and free of loose material. The advantages of using a tile covering are that they are non-porous, which means the covering is completely sealed, and a problem such as swelling or becoming disturbed does not happen. They are low maintenance as non-porous surfaces do not absorb paint, oils, or other chemicals. Therefore cleaning is relatively easy and simple when compared to a plastered finishes and provide a long term finish, as well as being easily replaced.

It can be seen that although there are disadvantages to installing a plastered finish over other, it is in my opinion that the advantages of using a plastered finish far out way the disadvantages and that based in the office environment it allows for modification and adaptation including redecoration.

Bibliography

CEM (2007) ‘Floors and Walls’, Paper 8014. Reading; The College of Estate Management.

CEM (2012) ‘Stair Construction’, Paper 8015. Reading; The College of Estate Management.

CEM (2012) ‘Fire protection’, Paper 8016. Reading; The College of Estate Management.

http://www.ehow.co.uk/info_8699796_plaster-wall-advantages-disadvantages.html (Last accessed 8 June 2013).

http://www.planningportal.gov.uk/uploads/br/BR_PDF_AD_K_2013.pdf (Last accessed 8 June 2013)

http://raisedaccessflooringcompany-uk.com/ (Last accessed 8 June 2013)

https://workspace.imperial.ac.uk/civilengineering/Public/Technical%20papers%20B/30B-Larsson-High%20Raised%20Access%20Flooring%20Containing%20Industrial%20By-Products1.pdf (Last accessed 8 June 2013)

F104TEC