The Building Control (Amendment) Regulations 2014 (the “Regulations”) came into effect on 1 March 2014 affecting both public and private sector projects. This followed on from concerns arising from high profile industry cases ranging from contractor insolvencies, defects and fire safety breaches throughout recent years, such as the much publicised Priory Hall development. Much of this has been attributed to below standard adherence to building control across the board, from design to supply of materials and works practices. This highlighted the real need for a more robust building control regime and increased levels of professionals and contractor accountability from the outset to completion of works
These regulations are to be kept in conjunction with the existing regulations and with the Documents known as the “Technical Guidance Documents” (TGD which give guidance on how works may comply with the performance requirements of the Regulations)
(O’Cofaigh, 2014) (deLongchamps, 2015)
The regulations will apply to:
- The design and construction of a new dwelling,
- To any extension to a dwelling involving a floor area of more than 40 square metres.
- Works where a fire safety certificate is involved.
Compliance with the provisions of the new regulations will be of great importance for building owners, purchasers, or prospective tenants because the regulations prohibit the opening, occupation or use of a building until a Certificate of Compliance on Completion has been filed and registered by the building control authority
There are various new roles identified in the Regulations. The Owner has primary and legal responsibility for the Building. The Builder is appointed to build and supervise the works. The Design Certifier is responsible for designing works, compiling plans and specifications and inspects where appropriate. The Assigned Certifier is a new professional role responsible for jointly certifying compliance with the Regulations and implementing the inspection plan. Ancillary Certifiers include other consultants and specialist designers/sub-contractors. The Building Control Authority maintains the register, procures the validation as well as carrying out risk inspections. (Anon., 2014)
The principle changes introduced by the new regulations are as follows:
There is a new form of Commencement Notice, which must be signed by the owner of the works, should be filed electronically via the BCMS or set out in the form as attached to the Regulations. No work can commence without a valid Commencement Notice and one cannot be retrospectively obtained. The documents required include all plans, drawings, and calculations, which will demonstrate that the building will comply with the standards imposed by the Building Regulations. (O’Donnell, 2014) (Soliciters, 2014)
A Preliminary Inspection Plan must be submitted with the application. This is a certification furnished by the Assigned Certifier, i.e. a design professional, that the building or works is in compliance with the requirements of the Building Regulations and outlines how compliance will be achieved. The Assigned Certifier is appointed by the Building Owner and must be either a registered architect, registered building surveyor or chartered engineer, the assigned certifier must undertake to inspect and coordinate and activities of others during construction, and to certify the building works on completion. (O’Donnell, 2014)
There must also be a notice of an assignment of an Assigned Certifier. The building owner must nominate to the building control authority the Assigned Certifier who will perform inspections throughout the lifetime of the works and certify compliance once the works have completed. The form must include: (Soliciters, 2014)
- Confirming building owner has assigned the assigned certifier.
- Confirms building owner is satisfied in regards to competence of assigned certifier.
There must also be a notice of the assignment of a builder. There needs to be confirmation that the building owner has assigned a Builder for the works and that the building owner is satisfied that they are competent to complete the work.
There must also be a certificate of Design completion. A Design Certificate must be lodged with the Commencement Notice, which must be signed by the Design Certifier who must be either a registered architect, registered building surveyor or chartered engineer. The deign certifier must confirm the following in this certificate:
- Confirm that he/she is competent to carry out design and coordinate.
- Confirm that any certs, ancillary certificates have been done by design professionals using reasonable skill, care and that they comply to the building regulations.
It must be signed by the assigned certifier. States that the assigned certifier will use care, skill when inspecting the works and that work is done in accordance to building regulations.
The builder must complete this confirmation that the he/she has been commissioned by the building owner and that the builder is to construct the building in accordance to plans, specifications etc. as laid out in the commencement notice. It also states that the builder makes sure that any person employed will be competent to undertake required works.
The builder must also cooperate with inspections laid out and prepared by assigned certifier and he/she will take reasonable steps to ensure that the builder shall certify that the building or works is in compliance with the requirements of the Building Regulations insofar as they apply to the works
Not only is a commencement notice required but a Certificate of Compliance on Completion. There are two parts to this certificate, part A is to be completed by the builder and art B by the assigned certifier. It should be accompanied by such plans and other documents outlining how the completed works or building differ from earlier submission and how it complies with the Building Regulations, it should also be accompanied by the inspection plan as implemented by the assigned certifier. Once this has been summited to the building control authorities, they will confirm within 21 days whether the certificate is valid or not. A Certificate of Compliance on Completion must be sent to the Building Control Authority and included on the statutory register before works or a building to which these regulations apply can be opened, occupied or used. All this highlights the continued focus on compliance from design stage to works completion. (O’Donnell, 2014)
As a result of these regulations, especially for non-commercial buildings there has to be better quality of buildings as it won’t be possible any longer for those building their own home to build using direct labour with an architect, charted engineer or building surveyor, this means that there will be a continued monitoring process throughout the completion of the building from design stage to work completion. This will result in much better quality of building, though at a much higher cost.
Urbanisation made cost of land high and it necessitated to go deeper into the ground and also towering vertically towards the sky. A deep excavation allows clients to maximum amount of floor space as well as an increase development potential. He amounts of deep excavation pits in city centres are increasing every year. The challenge for basements are, safe method of construction and minimum damage to adjacent structures, exclusion of ground water, water tightness, vapour tightness, damp proofing, tanking, drainage and achieving suitable internal environments for the occupancy. In this context, analysis and design of proper deep excavations and their supporting systems are essential. Even in complicated urban settings, deep retaining systems have been deployed successfully by overcoming construction challenges.
In order to ensure that safety procedures are in place to eliminate these risks a planned management system must be in place, methods statements, safety method statements, Risk assessments and safe system of works.
Before commencing work on any structure below ground level a thorough site investigation and examination of soil and water levels should be made. The site investigation will gather all the relevant information that the Engineers require that will allow them to decide what basement system is most beneficial for the project. Soil sample will be taken and analysed and will allow Engineers to decide what retention system is to be required.
Before any construction starts a site survey must be carried out to establish the followings points: (IHS, 1995)
- The level of the water table which will vary with the time of the year
- The ground conditions
- The presence of existing drains
- Possible ground contamination or radon: effects of contaminants on materials used in basement construction must be considered (Bre, 2007)
Level of water table;
Level of water table are significant, in summertime the level could be lower and in winter time the level could be much higher.
This investigation identifies the levels of the various soil or rock types on site, each group contains soils with similar engineering behaviour, and engineers divides the ground into five categories
- Granular soil (sands or gravels)
- Cohesive soil (Clays)
- Organic soil (peats)
- Fill or made ground
- Support to Boundary Walls during excavations and permanently.
- Stability of sides of Excavations.
- Ground water and de watering during construction.
- Neighbours and neighbouring/adjoining properties.
- Diversion of Services.
- Drainage of site and New Basement. Decide on surface and ground water disposal per Local Authority Regulations during and on completion of works.
- Access to and from site for vehicles and plant and manoeuvrability on site.
- Temporary Boundary fencing of site and Health and Safety measures for public and workers for duration of works.
- Maximising Floor Area of Design.
- Working to agreed Budget and Costings.
- Dealing with Client’s instructions and requirements.
- Maintenance implications for Designs chosen.
- Workmanship of workers.
- Agree in writing the condition of party walls and any adjoining structures with neighbours before commencement of works, and on completion of works.
- Structural Engineer required for structural analysis and design of various aspects of work.
Waterproofing Regulations and Options
One of the major problems with deep basement construction is ensuring it remains waterproof, in keeping with the code: B.S 8102 1990. This code classifies three basic types of water resistant construction – Tanked protection, Structural integral protection and Drained protection.
To obtain a complete exclusion of moisture is the main consideration when designing a basement. Where the water table is high water may be under considerable pressure. To create effective tanking of a basement, it is required that the walls and floor should be resistant to the passage of water. However, on a relatively dry site, drained cavity construction can be used as
an alternative to tanking provided measures are included to remove any water from a drainage channel.
B.S 8102: 1990, This code identifies three basic water resisting forms of construction.
- Type A – Tanked Protection
- Dependent on a waterproof membrane.
- Type B – Structural Integral Protection
- Water resistant concrete with waterbars incorporated into the joints
- Type C – Drained Protection
- Drained cavity incorporated into walls and floors
Basements are classified according to the proposed end-use and therefore this will influence the amount of water ingress and thermal performance rating the structure will have to maintain. The table below is the guidance on the design and construction of concrete basements outlines the various basement types and their expected performances:
|Table: Guide of level of protection to suit basement use|
|Grade||Basement Usage||Performance level||Form of Construction||Comment|
|1||Car Parking, Plant rooms (Excluding electrical equipment) Workshops||Some seepage and damp patches tolerable||Type B. Reinforced concrete design in accordance with BS 8110||Groundwater should be checked for chemicals which may have a deleterious effect on the structure or internal finishes|
|2||Workshops and plant rooms requiring drier environment; retail storage areas||No water penetration but moisture vapour tolerable||Type A. Type B. Reinforced concrete design in accordance with BS 8007||Careful supervision of all stages of construction is necessary. Membranes can be applied in multi-layers with well lapped joints.|
|3||Ventilated residential and working areas including offices and restaurants etc., leisure centres||Dry Environment||Type A. Type B. Reinforced concrete design in accordance with BS 8007. Type C. With wall and floor cavity and DPM||As grade 2|
|4||Archives and stores requiring controlled environment||Totally dry environment||Type A. Type B. With reinforced concrete design to BS 8007 plus a vapour proof membrane. Type C. With ventilation wall cavity with vapour barrier to inner skin and floor cavity with DPM.||As grade 2, As grade 1|
In the design of an earth retaining system for deep excavations, a number of factors need to be examined and considered to understand what method to use:
- Foundations of adjacent properties and services
- Designed limits on wall and retained ground movements
- Subsoil conditions and ground water level
- Working space requirements and site constraints
- Cost and time of construction
- Flexibility of the layout of the permanent works
- Local experience and available construction plant
- Maintenance of the wall and support system in permanent condition
When choosing an earth retaining system it depends largely on what the building is used for (car park, living space) and what the surrounding site conditions are (water level, soil type). The most common method used today in Ireland is Secant pile wall, but other methods are used as well. The following are the most common soil retention systems:
- Sheet pile wall
- Soldier pile wall
- Contiguous bored piles wall
- Secant piles wall
- Diaphragm wall
Secant Piling Secant piling involves the installation of concrete piles which interlock and therefore provide a continuous concrete wall. The piles are installed in a hard-soft (more commonly) or hard/hard arrangement. The soft piles are installed initially using a soft concrete mix (e.g. C7N) and these piles are unreinforced. As the hard piles are installed they secant into the soft piles on either side. The hard piles are constructed using structural concrete (e.g. C35N) and are reinforced. The hard piles therefore provide all the structural strength and stiffness. Subject to issues of tolerance, quality and stratigraphy a secant pile wall can provide a near total ground water cut-off in the temporary condition. In the permanent condition a secant pile wall should be considered to be “Type A” in accordance with BS8102. That is to say the structure itself does not prevent water ingress. Protection is dependent on a total water or water and vapour barrier system applied internally or externally. As with contiguous piles, a secant pile wall can either be temporary or incorporated into the permanent structure.
- The Secant Piles give lateral support to the sides of the excavation as well as establishing stability for the foundations of the granite boundary walls.
- The main advantage of secant piles wall is that it gives full protection in sensitive and collapsing soils and also the ease of coring into rocks.
- The piles are interlocking and will give very good protection against the ingress of groundwater during the excavation and construction work.
- Secant bored piles wall is constructed much quicker than many other retention systems.
Assessing the quality of concrete surface finishes is a matter of opinion since it is subjective rather than objective. Not surprisingly, there is often controversy and disagreement as to whether or not a particular finish that has been achieved is poor, satisfactory, good, or perhaps the best that could be achieved in the circumstances. Usually the question is whether or not the finish achieved has been in accordance with the specification requirements, or with the intent of the specification, which may not be the same thing. This document gives some guidance on achieving good quality finishes. (Society, 2013)
A significant proportion of concrete placed today is required to produce a good surface finish for architectural purposes.
Concrete gives greater scope for finishability specification.
Clause 4.1 requires the specifier (purchaser) to “ensure that all relevant requirements for concrete properties are included in the specification to the producer.” “The specification shall include any requirements … needed for transportation after delivery … or further treatment. The specification shall, if necessary, include special requirements (e.g. for obtaining architectural finish)” (Roberts, 2016)
It can be seen therefore that producing a good concrete finish depends on teamwork in which the concrete placer is only the last link in a chain that should start with the specification. To produce a good finish, a concrete complying with the above guidelines should be specified. Both the producers and purchasers of the concrete must be aware of these special requirements.
The appearance of as-struck concrete is always influenced by the interaction between a number of factors. For example, colour is affected not only by the concrete’s constituent materials, but also by the absorbency of the formwork and by the execution employed
in its fabrication and use.
These factors may be considered under three main headings:
- The correct quality of concrete, which has been designed to achieve its ‘finishability’.
- The use of the correct type and quality of form face material and release agent suitable for the finish specified.
- Workmanship, both in producing the formwork and mixing, placing, compacting and finishing the concrete. (Roberts, 2016)
Most specifications take into account the second requirement for the right quality of formwork.
Generally there is a separate requirement for the formwork to produce specific finishes. Similarly, all experienced contractors and formwork sub -contractors are aware of the requirements for good workmanship in production of the formwork and the placing and compacting of the concrete. However, very few specifiers and formwork contractors seem to be aware that the concrete should not only have a characteristic strength as specified, but should be suitable to achieve the required finish. Very few, have separate items for concretes to produce good ‘as – struck’ finishes.
Very often a lot of money is spent and time and effort taken to produce good formwork and to place and compact the concrete correctly, but the results are disappointing because of the use of a concrete with little or poor ‘finishability’. This has resulted in various avoidable blemishes on the surface, very few of which are due to the formwork materials or the workmanship.
For formwork, it depends on the type of formwork being used that will determine the permeability, likelihood of blowholes, type of concrete finish and the colour of the concrete:
Steel is completely impermeable, blowholes are likely, shiny finish and it provides a uniform colour.
Plywood formwork with a resin impregnated film is a more uniform colour with less blowholes but there is a risk of dark lines resulting from the wood edges absorbing water.
Controlled permeability formwork (CPF) – micro-porous plastic sheet lining is another type and it has fine pores permeable to air and water, providing a degree of porosity to act as a filter to retain the cement and all other fine particles in the mix but some of these are only intended to be used once.
The finished concrete surface will take on any imperfections in the face of the formwork and it is therefore important that care is taken of the formwork face. The following require particular attention.
Grout or mortar will ooze out of imperfectly sealed gaps between formwork and existing concrete and run down the face of the completed work. If the surface will not be seen, then
in general, this does not matter. However, the run should be removed if the surface appearance is important.
Lipping at Joints
If the formwork at a construction joint, either horizontal or vertical, has not been properly tightened on to the hardened concrete of the preceding pour, grout runs are likely, and there may, as a result be lipping, sandy areas and slight honeycombing may occur.
It is almost impossible to fill tie-bolt holes so that they merge with the rest of the concrete. It is a good idea with exposed concrete surfaces to locate the tie-bolt holes in a predetermined pattern that can be made into a decorative feature.
Concrete cast against impermeable forms is liable to have more blow-holes than where forms are even slightly permeable, for example, impermeable steel compared with MDO plywood. However, several of the examples appear to contradict this where steel forms have produced concrete virtually free from blow-holes. When blowholes are small it is unnecessary to fill blowholes unless they are greater than 5mm. When the appearance is not important the blowholes can be filled individually.
(Barnes, 2015) (Society, 2010)
Concrete mix also plays a key role in achieving a good concrete finish.
Visual concrete – Planning and Assessment (3) gives five guidelines that have been found generally to produce a concrete with good ‘finishability’
Classes of finish were therefore defined as:
- Rough where there is no requirement for the concrete finish to be seen
- Ordinary where appearance is not a prime consideration
- Elaborate for those surfaces with a need for a good appearance
It is to the recognition of concrete that so few criticisms or complaints are received on the vast number of construction put in place. While it is easy to determine the properties of the hardened concrete that will be suitable for the intended purpose, great care is required throughout the entire construction process to ensure that the hardened concrete actually has the desired properties. When a blemish appears on the surface of a concrete slab it will likely be one of these: blisters, cracking, crazing, curling, delamination, discoloration, dusting, efflorescence, low spots, popouts, scaling, or spalling.
Cracking of concrete occurs frequently Cracking can occur as a result of a number of factors such as such as drying shrinkage, thermal contraction, restraint (external or internal) to shortening, subgrade settlement, and applied loads.
It is important at design stage that causes of cracking are taken into account so preventative steps are taken into consideration so cracking can be significantly reduced.
Cracks that occur before hardening usually are the result of settlement within the concrete mass, or shrinkage of the surface (plastic-shrinkage cracks) caused by rapid loss of water while the concrete is still plastic.
Plastic shrinkage cracks are usually only small which can occur before the final finishing on days where it is windy or where there is low humidity or if there is a high temperature. This can cause surface moisture to evaporate faster than it can be replace by rising bleed water. Plastic shrinkage cracks occur at various lengths and can penetrate to mid-depth of the slab.
When drying, hardened concrete shrinks around 1.6mm in 3 meters. To control the location of cracks and to accommodate shrinkage due to thermal contraction, contraction joints should be placed at regular intervals.
The total water content of the concrete is probably the most important feature that has the greatest influence in drying shrinkage properties of concrete. As the water content increases so does the shrinkage. If there is an increase in the sand content and a decrease in the size of aggregates, then shrinkage increases because smaller aggregates do not provide a good internal restraint to shrinkage. Using calcium admixtures can also have a negative effect on shrinkage but an increase in cement content have little to no effect on shrinkage as long as the water content is not increased significantly.
Concrete also has a thermal expansion and contraction, if concrete is placed at high midday temperatures it will contract as the temperatures cool dramatically during the night.
Thermal expansion can also cause cracking. Insufficiently compacted subgrades and soils susceptible to frost heave or swelling can produce cracks in slabs. Overloading of concrete slabs also results in flexural crack formation and possible failure
The following outlines some of activities that can be done to reduce or prevent cracking:
- Use proper subgrade preparation.
- Minimise the mix water content by maximising the size and amount of aggregates.
- Avoid Calcium Chloride admixtures.
- Use spray applied finishing acids to prevent rapid loss of moisture.
- Provide contraction joints at reasonable intervals depending on the concrete finishing.
- Provide isolation joints to prevent restraint from adjoin elements of the structure.
- Prevent extreme changes in temperatures.
- Make sure the concrete is cured properly and make sure it is properly place and is consolidated and finished.
- Use synthetic fibres to help control plastic shrinkage.
Modern Methods of Construction
MMC (Morden Methods of Construction) is the process and technologies which involve prefabrication, off-site assembly and various forms of supply chain specifications, which have become an integral part of the construction industry in the last 10 years, to offer significant potential to minimise construction waste and they potentially save on time and materials as well as high standards of quality over traditional methods. There are five categories to classify MMC (The Concrte Society , 2004)
- Volumetric: Three –dimensional units or modules manufactured in a factory, fully fitted before begin transported to site. Erected on foundation to form dwellings (Mobile Homes)
- Panellised: Flat panels units manufactured in a factory and transported to site for assembly into a three-dimensional structure (Timber, steel frame and pre-cast)
- Pods: Pods are used in conjunction with another construction method. Examples are bathroom or kitchen pods (Pods for student’s accommodation or hotels)
- Sub-assemblies and components: Larger components incorporated into new homes. They include roof and floor cassettes, prefabricated chimneys, porches and dormers, and I-beam.
- Site based manufactured MMC: Methods of construction used on-site and the use of conventional components in an innovative way. (Stick build timber frame, Insulated concrete formwork and Glue laminated) (NHBC Foundation, 2016)
The benefits of using fast track construction methods, such as pre fabrication, allow the time spent on the site to be reduced. This means that the construction process occurs over a shorter period of time therefore, when done correctly, saving all parties involved both time and money.
Another advantage of the use of prefabricated units is the huge reduction in the volume of site spoilage associated with the current practices of over ordering and poor site handling in the traditional construction methods. This has an important bearing on both time and cost when one considers the astronomical costs of getting rid of waste in the Irish construction industry today. (Hyden, 2016)
There are generally problems with lack of compatibility where prefabricated components are not considered until later on in the construction process. Also changing the design of an ongoing project to use prefabricated components can introduce realignment problems, as components are generally delivered to site to fit a specific set of dimensions. (Hyden, 2016)
Tunnel form is a formwork system that allows the contractor to cast walls and slabs in one operation on a daily cycle. It combines the speed, quality and accuracy of factory/off-site production with the flexibility and economy of in-situ construction and is recognised as a Modern Method of Construction
The result is a cellular reinforced concrete structure, the surfaces of which are of sufficiently high quality to require only minimal finishing for direct decoration, while the end walls and façades are easily completed with thermally insulated units that can be clad as required. The system creates an efficient load-bearing structure for use in a wide variety of applications. It is particularly effective in projects suited to repetitive cellular construction such as residential blocks, hotels, student accommodation, barracks and prisons. The solid, strong monolithic structure can be 40 or more storeys in height and the accuracy of the system suits the installation of prefabricated elements such as cladding panels and bathroom pods, offering further MMC options. In Europe, tunnel form construction is competitive for much smaller projects such as blocks of six apartments but is yet to be used on that scale in the UK. The steel tunnel forms create spaces spanning 2.4 to 6.6 m. These can easily be subdivided to create smaller rooms. Where longer spans (up to 11 m) are required the tunnel form is extended using a mid-span section. (The Concrte Society , 2004) (Rupasinghe, 2006)
Figure 1: Twenty Four Hour Cycle of Tunnel Form
(The Concrte Society , 2004)
Queen Mary and Westfield College, University of London
The concrete shells for this village of six blocks for Queen Mary and Westfield College, University of London, varying in height from four to eight storeys, were constructed to a fast-build programme within 26 weeks. The finished buildings contain apartments with bedrooms and dining room/kitchens, offering a range of accommodation for 1000 students.
Planned around the tunnel form 24-hour cycle, using two sets of tunnels, each producing two bays, as its requirements would drive the programme. The dimensionally accurate and modular nature of the system led to the choice of bathroom pods, which eliminated repetitive trade fixing. Two bays, typically 6.3 m wide by 10.3 m deep, were constructed in each cycle.
The superstructure – frame, floor slab and internal walls – for a 175-bedroom block was built in only 32 days. Throughout the contract waste ready-mixed concrete amounted to only 0.15% of the total delivered. (The Concrte Society , 2004)
The Fire Certificate states that a dwelling complies with Part B of the Building Regulations 2011. It shows that there are adequate facilities put into the building and states that the building is designed in such a way that limits and prevents the spread of fire. It is vital that all building comply with Part B of the Building Regulations.
Under current Building Control Legislation, it is necessary to have Fire Safety Certificates for all new commercial buildings and if there is a material changes, material alteration or an increase in floor area in an existing building.
It is vital then that this is considered at design stage to ensure that the final design will be in accordance with Part B. Once the final design drawings are issued the Fire Certificate Application can be prepared and lodged with the Fire Services Section of the Local Authority.
(KELLEHER Surveyors, 2017)
When applying for a Fire Safety Certificate, it must include:
- A valid Fire Safety Certificate application must include:
- A completed application form
- Relevant fire safety drawings in duplicate
- A fire safety report in duplicate.
- Site location maps in duplicate.
- The appropriate fee
Build Regulations Part B 2011
The building Regulations deals with 5 keys areas in relation to fire safety.
Regulation B2 – Means of Escape
Regulation B2 – Internal fire spread (linings)
Regulation B3 – Internal fire spread (structure)
Regulation B4 – External fire spread
Regulation B5 – Access and facilities for the Fire Service
It is the responsibility of the project team to ensure that this procedure is fully complied with.
Means of Escape (B1)
This section deals with making provision for the early warning of a fire (fire alarms, heat alarms, smoke alarms etc.) and an appropriate means of escape to a place of safety outside that is accessible at all times during the day.
Means of Escape – When dealing with taller properties up to 4.5m above ground as such the proposed dwelling is, the regulations state that all habitable upstairs rooms (bar kitchens) that are only accessible via one set of stairs should provide a window or door or direct access to a protected stairway for escape in the event of a fire. (DIY Doctor – Part B, 2011) (Regulations)
All upper floors within the proposed dwelling have stairs, they should be:
- Be a protected stairway.
- Connect the ground and all upper storeys
- Either deliver directly to a final or give access to not less than two independent escape routes delivering to alternative final exits
Since there are less than 500 occupants within this dwelling two means of escape is sufficient. As alternative escape route by way of an escape stairway should be provided from each storey which has a floor 7.5 m or more above the ground or access level. Where the access to the alternative escape route is by way of the protected stairway, the protected stairway at or about 7.5 m above ground or access level should be separated from the lower storeys or levels by fire resisting construction. (DIY Doctor – Part B, 2011) (Regulations, 2006)
Fire Alarms – It is necessary that fire alarms are fitted into all new dwellings to be in line with the recommendations stated in BS 5839-6:2004 to a minimum of Grade D category LD3 standard. The location of smoke alarms, particularly in relation to doorways to bedrooms and the spacing of units, should be such as to ensure that the audibility requirements specified in BS 5839: Part 6: 2004
If installing a smoke and heat detection system, this will need to conform to BS EN 14604:2005 for smoke and heat alarms or BS5446-2:2003 for fire detection and fire alarm devices. In either case they need to be mains powered and feature a backup power system such as a battery.
In circulation areas, no door to a habitable room should be further than 7.5 m from the nearest smoke alarm. (DIY Doctor – Part B, 2011) (Regulations, 2006)
Smoke Detectors –Automatic smoke detection should be provided. An LD2 system incorporates suitably located and interconnected detectors in all circulation areas that form part of the escape route and in all rooms or areas, such as kitchens and living rooms, that present a high fire risk. Heat detectors should be provided in kitchens. Dwelling houses with up to three storeys above ground level should have at least an LD2 system so for this proposed dwelling a LD2 system will be used.
Sensors should be mounted between 25mm and 600mm below ceiling level or 25 – 150mm if they are heat detectors or heat alarms (DIY Doctor – Part B, 2011) (Regulations, 2006)
Internal Fire Spread (Linings) (B2)
This section deals with how a dwelling is built in terms of the materials used to construct walls, floors and ceilings. All materials should resist flame spread, also when ignited any heat released or fire growth is limited. This is particularly important in circulation spaces where linings would offer the main vehicle for fire spread.
Walls and ceilings should all have a rate of heat release or a rate of fire growth. They shall offer adequate resistance to the spread of flame over surfaces, it should have a minimum of 30-minute fire resistance.
The surface linings of walls and ceilings should have the following classifications: Class B – s3, d2 (European class) or Class 0 (National class) in other circulation spaces including the common areas of flats and maisonettes. (DIY Doctor – Part B, 2011) (Regulations, 2006)
Internal Fire Spread (Structure) (B3)
This is very similar to the section discussed above which must limit the spread of fire only in this section it I the property of the dwelling.
This section states that in the case of a fire the building structure will maintain its strength for a minimum amount of time and where conjoining buildings share the same wall, the wall must be designed resist fire spreading between buildings.
Structural frames, beams, columns, loadbearing walls (internal and external), floor
structures and gallery structures, should have at least the fire resistance.
This section deals with two ways the spread of fire can be restricted:
- Prevent rapid fire spread which could trap occupants of building.
- Reduce the chance of fires becoming large which could harm those in the vicinity of the building as well as occupants of building.
Every compartment should have complete barrier to fire between compartments they separate. Compartment walls should run the full height of the building in a continuous vertical plane. Hidden voids in the construction of a building provide a ready route for smoke and flame
spread, they should be concealed. (DIY Doctor – Part B, 2011) (Regulations, 2006)
External Fire Spread (B4)
The basis of section B4 of this document looks at the external area of the building (e.g. walls and roof) and aims to ensure that, in the event of a fire, both of these elements resist the spread of flame across their surfaces and on to any surrounding structures. The position, usage and surroundings of the given structure are also taken into account. Since this dwelling is in close proximity care must be taken.
The external envelope of a building should not provide a medium for fire spread. The use of combustible materials for cladding framework, or of combustible thermal insulation as an over cladding in drained and/or ventilated cavities, may present such a risk in tall buildings, even though the provisions for external surfaces.
An area or wall is taken to be facing a boundary if it faces the boundary at 80° or less.
When a wall is located more than 1000mm from a boundary, the following items will need to be met:
- The total unprotected area does not exceed any of the methods stated in paragraph 9.13 of Document B (DIY Doctor – Part B, 2011) (Regulations, 2006)
Access and Facilities for the Fire Service (B5)
A dwelling must be designed and built so that it gives adequate access to firefighters and to the fire service so that in the case of a fire they are able to deal with it as required.
There needs to be access at the rear of the building so that high access machinery such as platforms etc. can access as required.
In respect to vehicle access, this will need to conform with Table 8 of Document B, Volume 1.
Where dead-end access is present, a turning area will need to be provided, where the access route is over 20m in length.
There must also be the provision of an internal fire mains. Rising mains, serving floors above ground or access level; or – falling mains serving levels below ground or access level. Internal fire mains may also be of the “dry” type which are normally empty and are supplied through hose from a fire service pumping appliance, or they may be of the “wet” type kept full of water and supplied from tanks and pumps in the building. Where internal fire mains are installed, they should be positioned so that at each level other than ground level there is one main for every firefighting shaft. (DIY Doctor – Part B, 2011) (Regulations, 2006)
The outlets from internal fire mains should be sited in:
- (a) a firefighting shaft (see sub-section 5.3), or
- (b) a protected stairway, or
- (c) a balcony or walkway in the open air.
In the case of a building fitted with a dry internal fire main, access for a pump appliance should be provided to within 18 m and within sight of the inlet connection point
Access routes to buildings with any storey at more than 10 m above ground level should meet the standards for high reach appliances. (DIY Doctor – Part B, 2011) (Regulations, 2006)
The Longboat Quay apartments, built on Sir John Rogerson’s Quay by developer Bernard McNamara, have major deficiencies with their fire safety standards. Residents were told at a meeting last night that it would take around €18,000 each to fix the problems in the 299 apartments.
Initially problems were found with the fire alarm, in both the common areas and individual apartments. These problems were resolved earlier this year, at a cost of just over €1 million, but more serious structural problems remain. These include insufficient fire-stopping material in the walls. The building needs to be further “compartmentalised”, which involves the construction of fire and smoke barriers between apartments, to give occupants more time to escape in the event of a fire. (Irish Times, 2015)
A disability cert is provided by the building control authority which states that the building designed and constructed complies with Par M of the Building Regulations. The cert should include all drawings and the site layout. The following must be met to comply: (Doctor, DIY)
- Approach to the building
- Access and use to the building
- Circulation within the building
- Sanitary conveniences (Doctor, DIY, 2010) (Building Regulations)
Approach to the building & Access and use
It is required that an accessible means of approach to enter the dwelling and that there is a means of circulation around the building. The approach route is the entrance point from the boundary of the site. It is vital that there are no restrictions and that there is a level access to the building. A gradient of 1:50 or less steep is considered to be level. There must be a minimum clear width of 1.5 metres with edge protection of 150mm minimum hand rail on each side. The top and bottom landings should be at least 1800 mm long x 1800 mm wide a.
When there is a carpark, there must be designated, 2,4m wide by 4.8 m long nearby the entrance to accommodate all users including those with disabled parking permits.
Entrance door are to be a programmed automatic motion sensor door, with a minimum clear width of 1m in accordance with BS 70361:1996 (Doctor, DIY, 2010) (Building Regulations)
This allows people to move around the building with comfort, corridors and passageways should be wide (minimum of 1,2m wide) enough to allow a wheelchair user to easily move around the interior and any obstructions that may be present such as radiators, fire extinguishers, seating etc. All switches and sockets should be located between 450 and 1200mm from floor level. For stairs they are to be used as a means of escape. They must have a minimum width of 1.2m with a handrail either side 900 – 1000m above pitch line. For the proposed building fir doors will have mechanical feature which will hold the door open and let it close automatically if fire occurs. Handel’s on doors will be 900mm off ground (2010)
A WC door will need to open outwards and positioned so wheelchair user can access easily. The space within WC area should have a minimum turning space of 1.8 x 1.8 m. Cubicles must have a minimum width of 800 – 900 mm. Doors are to be inward opening with a minimum 450mm diameter turning space.(Doctor, DIY, 2010) (Building Regulations)
Cranes have a major impact on the efficiency and productivity of construction. It safely delivers the operator to the top of the tower without the need for them to climb, they are more convenient for lager jobs and they come in various heights and sizes. However, it is vital that a crane is correctly installed and positioned or anyway misused as the consequences can be disastrous.
The choice of crane is directed by the following factors:
- The characteristics of the load to be lifted
- The selection of suitable lifting gear. Remember that the weight of the lifting gear must be taken into account when sizing the crane
- The crane position, where the load is to be lifted from, the route that the load will take during the lift and where it will be landed
- Erection and dismantling constraints
- Site and environmental constraints
For the proposed building I have chosen that ‘A’ frame tower crane will be used to complete the building. This is the most common type of crane and is available in a wide range of capacities from 45 metre tonne to over 2000 metre tonne. A frame cranes have a high capacity and allow materials to be moved around site with relative ease. However, the “A” frame needs access for erection and dismantling which can be problematic at the end of a project
For this building the crane will be positioned beside the Ginger man pup. This means it can be close to the construction and away from open roads and open car parks.
It also means loads can be lifted from either the front of the site or from the car park at the back of the site (Crane Position)
The building length as shown in the orange lines above is 12 meters and the building width as shown in the yellow lines above is 14 meters.
Therefore, the 180 HC-L 8/16 Litronic crane is to be used. (LIEBHERR, 2016)
Jib Length: 55m
Max Lift: 16,000kg
Jib End Capacity: 2,600kg
The luffing jib cranes in the HC-L series are used for high level work on constricted sites. In the luffed position of the jib between 15° and 70°, even when not in use, they can be slewed freely when used on sites with lots of cranes and overlapping slewing ranges. Various climbing and guying systems mean that there is almost no limit to the possible uses. (LIEBHERR, 2016) (Liebherr, 2017)
The weekly hire of the 180 HC-L 8/16 Litronic crane is €700 weekly for Flat tops and saddle jibs or €1,200 for Luffer type. (VALLA, 2016)
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