In this task, I will be providing a discussion in relation to the aspects of the technical components and elements in terms of the construction and design of the five-storey structure throughout this project, located on the Ormeau Embankment.
In order to achieve this I will be providing the discussion based on the key elements in relation the technical aspects, these will mainly consist around:
• water control within the structure
• the controlling of heat and air flow throughout the structure
• controlling sound
• lighting considerations
• overall structural support and movement
In terms of the construction of the basement, there were various challenges to face before construction. Firstly we had to deal with the high-water table, “Belfast Sleech, and soil content as it is quite close to the River Lagan.
However, using dewatering wells, piled foundations, external waterproof membrane and in-situ concrete system by using concrete formwork, will provide a secure and non-dampness basement.
There must always be a great emphasis on complying with British Standard in terms of the structure in the construction process in its entirety to ensure there are no structure defaults or weaknesses which could potentially lead to structural problems.
Water Control within the Structure
Within any structure, and this includes the five-storey building for the project on the Ormeau Embankment, there will be joints within the construction of the structure. There are many reasons in which why there are joints, which include multiple construction methods during the process, and change in materiality in certain junctions. In terms of the construction process for the five-storey, we must consider joints carefully in order to avoid any weak points occurring in the structural makeup of the building.
We must be fully informed of the various categories of joints which may occur in the construction of the five storey structure. These include connection joints between similar materials and different materials. The similar materials may include the brick, the reinforced concrete slabs, both vertically and horizontally of the floors, walls, ceilings. In terms of different materials connecting between each other, this may include the doors, windows, brickwork, ceiling and floors. This will have to be remedied very closely and precisely as materials which are jointed or connected of contrasting materials are most of risk of being exposed to moisture and water externally, and this will lead to lasting problems within materials in terms of movement and expansion in size capacity.
The joints in the basement will be protected by using the external waterproofing method. This can be achieved in a number of different ways. External waterproofing materials such as membrane rolls, concrete sealer, and the waterproofed elements within the actual concretes production can all achieve the protecting the basement externally.
For this particular project, we will choose the installation of the membranes, both on the walls and floor of the basement, and if necessary, use concrete sealer internally to ensure as little seepages and damp patches as possible.
In relation to the rest of the structure, we must consider all the joint types, along with the proper procedures in order to protect them.
Due to the building being precast concrete based, with brick cladding panels and various structural steel components, we will be using a combination of protection elements.
For the joints running horizontally, the floor for example, I will be using joint sealant, which is an elastic liquid material. For joints running vertically up and down the walls within the structure, waterproofing joint tapes will be used.
In terms of weather proofing or waterproofing the joints around the windows and doors within the confines of the building, I will be using common silicone sealant.
Drainage will also be a crucial part of the protection element for both the building and the site. There are two categories of drainage that we must be aware of and
therefore plan, these are “surface water drainage systems” and “foul drainage systems”. These two drainage systems distribute two different elements re therefore are separate systems.
Surface water drainage systems help the carriage of rainwater from the external components of the structure. Surface water drainage is therefore defined in two categories; Above Ground Systems and Underground Pipework.
Above Ground Systems include roof drainage which consists of down rainwater pipes and gutters whereas Underground Pipework is the involvement of surface water sewers and drains.
In contrast, foul drainage systems are the carriage of water used from toilets and sinks, which will be definitely common in the case of our five-storey building. Again, there are two categories of foul drainage systems: Above Ground Systems and Underground Pipework.
The Above Ground Systems contain sanitary pipework whereas the Underground Pipework includes sewers and drains.
Due to the fact that for the five-storey building structure will be a flat roof structure, we must carefully put in place the proper procedure in order to fulfil total roof drainage.
Parapet roof draining system will be implied as the roof drainage for our project. There are many different categories of parapet drainage systems; however the selection for this building will be the “scupper method”, which directs the water through the wall and into the drainage downpipe. Scupper is made up of many components such as a set metal flange in roof cement and prime, before the commencement of stripping. Felt plies, metal decking, base flashing, membrane modified and various other flashing make up some of the components for the Scupper Parapet Roof Draining System.
Drainage systems will also be crucial in the basement section of the building. As touched on in “Section A- Construction of the Basement”, it was explained in greater detail that, externally, there would a special waterproofing membrane installed around the basement. However, there will have to be an outside drain pipe running along the exterior of the basement in order to channel the ground soil moisture away from the basement.
The weep holes will be located in key areas throughout the structure which may have an over access of water over time within a confined space, which, in our project will be present perhaps between the brick cladding panels, insulation and the block wall. In terms of where precisely to place the weep hole is simply at the bottom of a component. However, for the case of our project, we will be placing the weep holes between the brick cladding panels, in the in the mortar finish, and at the bottom of the floor to allow the water to drain towards the bottom of the concealed space.
In terms of both the overhang and drip, these both must be carefully considered as both are available in order in avoid any damage to the exterior of the five-storey building.
However, overhangs in particular are not just technologically important to the performance of the structure, but can also serve as key architectural design elements to the structure. This is clearly evident in the sense that it can dictate the quantity of shading around the openings within the structure and in take o solar heat. In addition to this, overhangs provide protection from weather at doors and windows, protect the basement of the structure from excess water, and also help regulate the temperature of the building.
Drips provide similar protection to that of overhangs in terms of protecting the exterior of the structure from the weather. Drips in a sense are designed to limit the amount of any rainfall or water from being in contact with the exterior surface of the structure.
Controlling Heat and Air Flow
Controlling the heat and air flow throughout the building will also be a crucial element in terms of the thermal performance of the structure.
In order to get the best ventilation systems installed within the structure, we must consider and explore all the possibilities. However, the seemingly best and most effective solution is natural ventilation.
Natural ventilation is dramatically low-energy in comparison to mechanical means of ventilation. Natural ventilation has many benefits such as economic improvements, environmental progression and the personnel within the structure will be provided with comfortable conditions in order to work.
In terms of what natural ventilation system to select, we have chosen the passive stack ventilation system. Passive stack ventilation is the most effective process as it uses a combination of environmental components in order to carry out its function. These components include buoyancy, crossed ventilation and an effect of suction, a result of air passing across the terminal. Passive stack ventilation system’s outlet is at the centre of the structure, and can be most efficient in relation to both internal and external cooling at night. The system also allows pre-warmed air intake during the cooler months of the year, while in contrast, allows sufficient airflow during the warmer part of the year.
In terms of mechanical means of ventilation, we may need to install various elements such as air conditioning, and mechanical heaters for during colder months of the year.
An insulation system is also crucially important in order to maintaining a warm within a structure and improves the overall thermal performance to a greater level. In relation to the five-storey building on the Ormeau Embankment, which will be a combination of brick-cladding panels, precast concrete slabs, steel beams, and block work, then we must greatly consider internal wall insulation.
Internal wall insulation is crucial to maintain a constant environment and prevent external temperature alternations to the temperature within the five-storey structure.
External wall insulation wall systems will consist of installing insulation onto protective cladding, which for this project will be the brick-cladding panels. However, this would drastically change the appearance of the structure externally, which we don’t want to achieve. Additionally, it will dictate the positioning of drainage down pipes and roof junctions. Therefore, we must ensure that the internal wall insulation is completed correctly and installed promptly to avoid any temperature changes within the structure.
In relation to what material to select for the internal insulation, the only disadvantage it will cause is that it will reduce the interior space. The two categories of internal wall insulation materials are rigid insulation panels, and insulators such as mineral wool. Mineral wall is more used with timer-stud walls and metal stud works. Therefore we will need to fix rigid insulation panels onto the inside block work of the wall.
The most common types of panels to use are polystyrene boards and polyisocyanurate boards. For this project we will select 100mm celotex insulation for within the cavity, attached to the outside of the block work, and we will use adhesive as a 13mm plasterboard finish for the inside of the block work.
Thermal Bridging is something we must also greatly consider in terms of achieving the heat and air flow within the building. Fundamentally, thermal bridging is a point within the structure which drastically increased heats transfer in comparison to the surrounding materials. The most common factors that influence this disconnection in the insulation, the insulation disrupted by a component or material of a higher thermal conductivity, or where there is lesser quantity of insulation.
The points, in which this may occur in the case of our five storey structure, are the roof joints at the wall height finish point, window and door joints, and perhaps at the precast concrete floor level and the steel beam supporting the brick column.
The selection of glazing for the building must be run in correlation in terms of trying to limit noise and shading into the structure. The windows selected for the five-storey structure will be closed double-glazed windows. The windows, if required, can also be soundproofed if required.
The glazing for the structure can greatly dictate how the building performs in terms of thermal performance. The glazing will consist of an energy rating and a U-value.
The U-value of the double-glazed window is vitally important in terms allowing a greater reduction of heat from within the structure to pass through the window.
The size of the windows and positioning also can dictate the thermal performance of the structure, so it will be important to have the correct position. If a great quantity of direct sunlight is allowed to enter within the structure, this can increase the heat within the structure immensely.
Noise reduction is also crucially important in terms of the architectural performance of the structure. Achieving noise reduction can be completed in a variety of ways such as construction of barriers around the structure on the Ormeau Embankment, the planning in relation to the site, the architectural conceptual design of the building and methods in terms of construction.
In terms of the planning of the site, we must greatly consider the alignment of buildings on and around the site location which can be used in order to lower the impact of noise. Acoustical site planning provides an amount of methods for greatly reducing noise.
In order to achieve this, many sites create areas used for maintenance facilities, utility and parking areas around the building between the receiver (five storey building) and the source (neighbouring buildings and vehicles). Orientation of the structure in a different direction from the noise source, placing the five-storey building more into the site away from the noise source and perhaps, constructing barrier buildings between the receiver and the source on the site.
The materials which can help to achieve in noise reduction can be range in a variety of materials. The materiality used often be provided in a fabric materiality, but can broad into heavy curtains and blankets with acoustic elements implanted into the material.
Mass & Thickness of the material elements within the construction of the structure are also important. Noise reduction can be greatly reduced by the quantity of doors and windows in the structure, for example less windows and doors greatly reduce this. However, for the fie-storey structure on the Ormeau Road, there will be an average amount of windows and doors installed.
Therefore, the thickness of construction elements will be crucial. These include the mass and thickness walls, both externally and internally, windows, doors, ceilings. The use of brick-cladding panels, block work and precast concrete floor slabs all contribute to reducing noise intake due to the mass and thickness
Using cavity partition within the structure will additionally create a more highly efficient reduction of sound, which will already be implied with the construction of the five-storey structure. The space in the cavity between the brick-cladding panels and the internal leaf of block work provides a width of airspace in order for air insulation to work.
Lighting into the structure, both naturally and artificially are both crucially important to the performance of the structure.
Natural light being able to travel into the structure is highly important as this provides individuals within the structure to experience more comfort.
Natural lighting into the structure will greatly reduce the need for artificial lighting and mechanical means of energy, there allowing the building to be more energy efficient.
In order to achieve natural lighting into the structure efficiently we must therefore consider elements such as glazing high-performing, daylight redirection components, shading solar components and daylight-optimised surface finishes.
Many technological and architectural design elements are crucial in order to get maximum natural lighting into the structure. Shading the building externally from daylight can reduce the heat gain of the structure, and therefore can heat up the building dramatically. Therefore, the parapet overhang roof structure will provide this. Additionally, the closed double-glazed windows will provide maximum daylight due to its size. In order to fully optimise this we must ensure that the visible transmittance, U-value, and coefficient shading elements all operate correctly.
Artificial lighting within the structure will be provided by electrical means, and it’s important to ensure the right category of artificial lighting is installed general lighting and emergency lighting will be installed with the five-storey structure.
The general lighting will there give the floor area throughout the structure the adequate illumination and can be achieved with overhead light installations on each floor level. On the other hand, emergency lighting, obviously used during emergency situations, will produce lighting in order to allow the occupants within the structure to leave safely.
Overall Structural Support and Movement
The overall structural support and movement of the building is crucial in terms of ensuring the building is structural safe to occupy within. Firstly, we must understand the different load types to ensure the building functions structurally. Due to the reason that the five-storey building will be used for office use, there is guaranteed to be present dead loads, such as tables, chairs, computers, brick, concrete, reinforced steel, etc. These are classed as dead loads as these elements are fixed in position. In turn, there is ways to distribute the dead loads to ensure that the support columns, beams and floors are structurally capable of being handle the load weights. A perfect example of how to achieve this is to position the beams at the bottom of the brick-cladding panels and the inner block work, which in turn can be directed towards the columns.
On the other hand, live loads are objects within the structure that vary and change around the structure, which for example, an actual occupant would be classed as a live object. Other example for within the structure of lie loads may include elevators, office floors, hallway, and staircases.