Tag: Drainage

When Do the NHBC Standards Apply to Balconies?

Posted on by Sajjad B

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When Do the NHBC Standards Apply to Balconies?

The National House Building Council (NHBC) Standards play a pivotal role in ensuring that new homeowners receive a property that not only meets but often exceeds their expectations for quality and safety. These standards are intricately designed with a focus on reducing risk and enhancing the end-user experience in their new home.

Unlike a British Standard or a Euro Standard, which may form part of the mandatory path to demonstrating compliance with building regulations, NHBC Standards apply specifically when NHBC is selected to provide the warranty for the building. It’s important to note that these standards are not universally mandatory; they are particular to NHBC’s warranty service.

NHBC is recognised as one of the most reputable leaders in the field, setting a benchmark for excellence in warranty protection. Although other providers like Premier Guarantee are also common, especially for high-rise buildings, they typically do not operate a separate set of standards. This doesn’t diminish the influence of NHBC standards; on the contrary, in the absence of balcony specific guidance prior to the BS8579:2020, they were really the only independent source of guidance so often served as a reference point for balconies.

One area where the NHBC Standards have been particularly focused, for various products but especially balconies, is in preventing water ingress into buildings. This issue has been a significant aspect of warranty claims over the years. With the lack of specific guidance in British Standard BS8579:2020 and Part H (or Document H in Ireland) regarding balcony-related drainage, the NHBC standards have often been adopted as a reference point for best practice, regardless of the warranty provider.

Ultimately, NHBC Standards are applied to projects that they will warranty. However, when a warranty provider has not yet been chosen at the early stages of a project, it is considered good practice to ‘start with the end in mind.’ Given that NHBC’s balcony guidance is more stringent than BS8579:2020 and what is typically required by other warranty providers, it is prudent for developers to aim to meet or exceed these standards from the outset.

Doing so ensures that the project is prepared to meet the NHBC’s rigorous requirements should they be engaged as the warranty provider. Additionally, by adhering to these more onerous guidelines, developers are able to guarantee a higher standard of construction, thereby reducing risks associated with water ingress and enhancing the overall quality of the living experience for the end-user. This forward-thinking approach is not only beneficial for meeting NHBC standards but also serves as a mark of quality and diligence that is valued throughout the industry.

2024 Changes to the NHBC standard which particularly impact balcony design

In 2024, a significant update was rolled out, especially effecting thermal efficiency and sustainable design. However there are a number of ‘minor points’ of change which have been tweaked which will be impacting balcony design. Some have already been applied for a while on projects but some are a little more surprising.

The 2024 balcony related updates focus particularly on drainage, loosely based on BS8579:2020.

Changes to 7.1

7.1.4 Has been updated to add a clause to stop balcony drainage from dripping onto balustrades below. The statement This is additional to previous requirements which is loosely based on the BS8579:2020 interpretated in NHBC’s perspective. Not draining onto vertical surfaces below reflects BS8579:2020 however the difference lies in the requirement for not flowing onto barrier edges and fascia’s of balconies which is not referred to in the British Standard.

In real terms this means that any stacks of balconies will need to have a drip edge projecting beyond the balustrade. The clause says:

 

“The rainwater drainage system may be based on conventional piped drainage or an edge drained design. In all cases the downpipes, overflows and edge drainage outlets should be positioned in the construction to provide effective drainage that will not cause water to flow directly down onto the walls and fascia surfaces below or barrier edges of balconies installed in any stacked multi-storey arrangement”.

 

There is also a new requirement to:

 

“designed with a projecting profile that prevents rainwater from either tracking back into any soffit or running straight down onto vertical surfaces situated below”

 

This change doesn’t change anything for the way that Sapphire balconies are designed but in essence means balconies need to have some kind of drip edge at the lip where it is discharged. Again, there is reference to vertical surfaces which matches the BS8579:2020 diagram and guidance.

Another new point relating to where the controlled drainage is being done using RWP (Rainwater Pipes). It would generally be considered standard practise and does not affect Sapphire Balconies design:

 

“designed with a downpipe shoe fitted where any downpipe outlet discharges above finished ground level, including above a drainage gulley.”

 

And also a standard not point balcony drainage to BS8579:2020. It has always been the case of what we would point people to for balcony guidance and again is best practise advise which doesn’t have an impact on what Sapphire do or the way we design.

Designs for drainage of balconies and terraces should follow BS 8579 guidance for the provision of discharge outlets with effective clearance, capacity and profile shape to throw rainwater clear of the edge and prevent residual dripping onto other parts of the building beneath.

Another couple of new clauses but ones we have seen multiple times on the more recent NHBC Warranty projects are now included on the new version of their standards. These points cover guidance around ground floor and entrances to buildings, generally following the common NHBC interpretation of BS8579:2020. Secondly, there is a point about water cascading down the building. Whilst our opinions differ considerably from this statement, based on the research and testing we have done which tends to suggests otherwise there is now the following wording:

 

“A design approach for free draining balconies can be accepted if rainwater will always be routed away from the building to drain via a suitably formed soffit drainage tray that directs water to run outwards over a continuous formed perimeter edge. But where this drainage design is installed for stacked balconies on multi-storey elevations – the rainwater will tend to cascade down from these edge drainage slots as water runs off each balcony.
Under typical wind driven rainstorm conditions the water runoff volumes from these balcony catchment surfaces will progressively increase in a downward direction until the full volume of water reaches ground level. This can adversely affect locations such as main entrances to apartment buildings as well as any access doorways and private gardens of individual homes situated at ground level. Therefore, in addition to the free draining balcony design there is a requirement for design of ground level drainage to effectively prevent ponding or flooding of water. This drainage design is required along all building perimeter locations where thresholds, access locations and other places of regular use will exist.”

 

There is new guidance specifically referencing free draining balconies. This is assumed to be what is called controlled edge draining in BS8579:2020. It here references a continuous formed perimeter edge. Again requiring a drip edge along the edge where drainage is being dispersed.

 

“A design approach for free draining balconies can be accepted if rainwater will always be routed away from the building to drain via a suitably formed soffit drainage tray that directs water to run outwards over a continuous formed perimeter edge.”

 

Guidance has been updated for 7.1.5 Flat roof, terrace and balcony structural design. Again this doesn’t effect the design of Sapphire balconies.

 

“Flat roofs, terraces and balconies shall support and transmit loads safely to the structure. The structure of the flat roof, terrace or balcony should:
be produced by an engineer in accordance with Technical Requirement R5, and BS EN 1991-1-1, BS EN 1991-1-3, BS EN 1991-1-4 and BS 8579: 2020 for balconies
be designed to address both short term and long-term deflection to provide an effective drainage strategy with no back falls or ponding. resist wind uplift by self-weight or by being anchored to the main structure – where required, holding down straps should be provided at maximum 2m centres at the perimeters
have adequate provision for the additional loads where a flat roof is to act as a terrace, roof garden, for support of permanent service equipment, and for additional loads during construction”.

 

There is however a reference to holding down straps which may see an increase in request relating to this.

Specific requirements for gaps around decking also remain in the standard and are split between edges and gaps between boards. Again not a change in intentions nor of our balcony design.

 

“As-built gaps of 10mm – 12mm should be provided between decking/paving units along perimeter upstands/thresholds. As-built gaps of 6mm – 8mm should be provided between individual units of decking or paving. Spacers and supports which raise the decking or paving should not obstruct the flow of rainwater to outlet(s).”

 

There is a new section referring to the use of metal balconies referring back to BS8579:2020. Again a welcome reference to a document we have been following for a long time.

 

“7.1.17 Metal balcony decking systems
Metal balcony framework structures and metal balcony decking systems should be designed and constructed as recommended in BS 8579 guidance for the design of balconies and terraces and their component parts.”

 

There is also new guidance relating to glass use specifically mentioning glass compliant with Part B fire regulations but it does not mention limitations under Regulation 7. It seems to indicate that the use of monolithic glass in a guarding is permissible for balustrading.

 

“be toughened glass, laminated glass (subject to meeting fire regulations) or glass blocks (suitably reinforced) where glazed balustrading is used”

 

What were Sapphire expecting to see which isn’t in the updated standards?

Previously the 30mm drip edge, referred to in BS 8579:2020, for where there is a vertical surface of the building (i.e. in scenarios where there is a warm space below a balcony or terrace) had been a frequent topic of conversation on projecting balconies. This has been the result of what we believe is a uncommon interpretation and application of one different application rather than the correct for the scenario show in the edge drained sketch in BS8579:2020. The only balcony and terrace related reference to 30mm drip edges in the 2024 standards is for where there are scenarios matching the BS8579:2020 sketch and guidance, for example parapet walls copings on top of inset balconies and similar scenarios. This matches the Sapphire interpretation of this guidance as these scenarios have a vertical surface of the building below and therefore needs a drip edge to avoid unsightly staining, water ingress etc.[/sapphire_textBlock][sapphire_imageBlock image=”13900″ notch=”” height=””][/sapphire_imageBlock][sapphire_textBlock]

NHBC Future direction of travel

At the Building For Tomorrow, London Conference on 27/02/2024, the NHBC provided insights into the evolving landscape of construction standards, particularly for balcony design and high-rise buildings. This section summarises the key points from the speeches delivered at the conference, outlining the “direction of travel” for the NHBC standards.

 

NHBC Standard Direction of Travel: Chris Hall presentation

 

Chris Hall, the technical innovation manager at NHBC, shared that the process of updating the standards is ongoing and typically operates on an 18-month rolling update cycle. Coastal standards are revisited every three years to reflect the latest in environmental and technical requirements. He highlighted the focus in England on future homes and building standard consultations, with Wales adopting the 2022 version of Part F, L, and O. Scotland is pushing towards a ‘passive house like’ standard as a mandatory building regulation.

In 2024, a new chapter was added to the NHBC standards focusing on engineering fill. Five chapters received major updates, including those on external walls and pitched roof guidance, complemented by 70 new CAD drawings. Minor updates were made to other chapters, such as chapter 7.1, and the 2025 process will aim for consolidation of these changes.

 

Overview of the Implications of Building Safety Act for High-Risk Buildings: Steve Evans’ Speech

 

Steve Evans, the Head of Technical Operations at NHBC, provided an overview of how the Building Safety Regulator’s new regime, operated by the Health and Safety Executive (HSE), will function and its implications for NHBC. Following the post-Grenfell changes to the building control regime, as of 1 October, high-risk buildings (HRBs) can no longer be part of the NHBC Building Control Scope, with building control set to become a regulated profession under the BSR Rules from 6 April 2024.

For NHBC, this means:

  1. Continuation as warranty providers for buildings.
  2. Managing HRB transitional provisions on projects still working to old regime.
  3. Implementing warranty pilot schemes for full compliance.
  4. Assisting the BSR on multi-disciplinary teams, ensuring teams demonstrate competency by 6/4/24.

 

Standards for High-Rise and Complex Buildings: Philip Smith’s speech

 

Philip Smith, a principal technical specialist at NHBC, discussed the need for a new standard for high-rise and complex buildings. The NHBC recognises the need to shift its focus from traditionally low-rise buildings to create specific and more focused guidance on the unique challenges posed by high-rise and complex building’s.

The NHBC has identified some particular areas where there is a gap between their standards and changing landscape in the high-rise sector includes legislation and regulation changes, the climate change and carbon-neutral agenda, future homes, and building standard consultations. There’s also an emphasis on Modern Methods of Construction (MMC) innovation, systemisation, and product certification changes highlighted by the OPSS. Particularly volumetric and panelised systems are increasingly common so that is an area of specific focus too.

Cladding and fire-related claims have significantly influenced the loss both in numbers and in value, prompting a new change control regime that impacts how changes are made and recorded throughout construction and the supply chain. NHBC standards are set to start aligning with the pace of change on MMC, particularly with volumetrics and panelised systems, as part of the PAS 8700 standard. NHBC continues to map out risks and changes in construction techniques, aiming to be simple, consistent, clear, and collaborative.

What Are the Practical Implications of NHBC Standards on Balconies?

The NHBC Standards, particularly those related to balconies, have practical implications that extend beyond compliance; they guide the design and construction processes to ensure the long-term integrity and usability of buildings. Here are three key points to consider:

A) Implementation of a Drip Edge

A drip edge is required at the front drainage edge of most balcony scenarios. This component is deemed crucial to fulfil the latest NHBC 2024 standards as it is aims at preventing water from dripping onto the guarding of the balcony below. It’s an essential consideration that serves to protect lower balconies in a stack or the building’s façade from water staining or nuisance. Sapphire has multiple ways of achieving this. The below images show how this can be done effectively and without the drainage having to run through small drainage slots which could be susceptible to becoming blocked or being too small outlets to deal with storm drainage.[/sapphire_textBlock][/vc_column][/vc_row][vc_row width=”70″ background_image=””][vc_column css=”.vc_custom_1710329272335{padding-top: 30px !important;background-position: center !important;background-repeat: no-repeat !important;background-size: cover !important;}” el_class=”gallery1″][sapphire_imageBlock image=”13905″ notch=”” height=””][/sapphire_imageBlock][sapphire_imageBlock image=”13911″ notch=”” height=””][/sapphire_imageBlock][/vc_column][/vc_row][vc_row width=”70″ background_image=””][vc_column][sapphire_imageBlock image=”13907″ notch=”” height=””][/sapphire_imageBlock][/vc_column][/vc_row][vc_row width=”70″ background_image=””][vc_column][sapphire_textBlock]B) Ground Floor Drainage Considerations

At the ground floor level, especially at main entrances needs more careful planning of the drainage is imperative to meet the newest guidelines. It’s essential to ensure that rainwater from balconies has been designed to minimise the nuisance of water discharged onto ground floor areas, especially the main access areas of buildings. This not only affects the aesthetic appeal but can also pose a safety hazard, especially in adverse weather conditions. Strategic placement of drainage solutions can help avoid creating slippery conditions or pooling of water in high-traffic areas. Design consideration needs to be made on how the balcony drains but equally how ground drainage is also done.[/sapphire_textBlock][sapphire_imageBlock image=”13918″ notch=”” height=””][/sapphire_imageBlock][sapphire_imageBlock image=”13919″ notch=”” height=””][/sapphire_imageBlock][sapphire_textBlock]C) Sustainable Urban Drainage Systems (SUDS) Strategy

In line with sustainable building practices, it’s necessary to consider how your Sustainable Urban Drainage Systems (SUDS) will function, particularly in preventing ice formation on pathways below where balcony drainage may discharge. This is especially crucial in areas/locations prone to freezing temperatures, where improperly managed drainage can lead to hazardous ice patches. To meet the NHBC standards it should be a consideration of principle designers and landscape designers, etc as to how the design should ensure that water is channelled away safely and does not contribute to potential hazards or damage landscaping.[/sapphire_textBlock][sapphire_imageBlock image=”13920″ notch=”” height=””][/sapphire_imageBlock][sapphire_imageBlock image=”13921″ notch=”” height=””][/sapphire_imageBlock][sapphire_textBlock]

Conclusion and Recommendations

Adhering to the NHBC Standards for balconies puts increased focus on dealing with drainage appropriately. Therefore it necessitates thoughtful design and engineering solutions to manage rainwater effectively. The spirt and guidance in the standards aims to prevent immediate water related damage, whilst mitigating long-term risks and ensure safety and comfort for building occupants. For balconies, achieving the NHBC 2024 standards does require more than building regulation and compliance with BS and EN standards. It will cost more and will mean considering this early. We are happy to assist at an early stage with this to give project specific guidance.

For those seeking to deepen their understanding of this topic and to explore innovative drainage solutions and approaches, reach out to use to book a rainwater CPD presentation. Additionally, Sapphire’s Drainage Whitepaper offers an in-depth look at effective drainage strategies, providing valuable insights and guidance. Both resources can prove instrumental in achieving a design that is both compliant and conducive to a safe and sustainable living environment.

Do bear in mind that if you are designing to NHBC guidance early on because it is a change to a façade related component, under the new Building Safety Regulator regime, once it is submitted through Gateway 1, then it is going to need to be used. Our advice is; be prepared, or make the decision on warranty providers at an early stage. Your choice, just remember façade related changes will not be easy and neither will cost be an acceptable justification.

You may also find this video useful in understanding the BS8579:2020 statistics.

https://youtu.be/MX_wyEds9WU[/sapphire_textBlock][/vc_column][/vc_row]

Is My Balcony Safe?

Posted on by Sajjad B

[vc_row width=”70″ background_image=””][vc_column][sapphire_textBlock]Is my balcony safe? What if a fire starts? What if it’s been installed incorrectly?

These are all questions our end-users will reasonably have living in a high-rise residential unit and as architects, developers, manufacturers, suppliers and installers, the onus is on all involved to justify, explain and reassure the end-user that their property, their home, is safe to live in.

In this article, we’ll be exploring the scope of making a balcony safe, from the design choices we make, to the materials used, to necessary maintenance and beyond. We’ll look into fire risks, drainage and how both are mitigated against through smart balcony design.

The safety of end-users and residents should be our number-one priority. Let’s look into how to make a balcony safe.

Materials used

A key principle of architecture is balance. Balancing the desire for attractive design with the crucial need for strong, safe construction. To ensure this type of strong and safe construction, there are three key areas to focus on from an early stage, looking at the materials used.

Firstly, designing for the long term. Sapphire’s balconies are typically designed to meet a 60-year lifecycle thanks to the aluminium we use in the construction of our balcony Cassettes. Aluminium is a strong material with flexible design possibilities, making it perfect for the extrusion of different types and shapes of balustrading. Critical Connections back to the building will normally be made of M30 stainless steel. The size means the are much more robust, both because of them being over engineered for a much stronger resistance to the moment forces and because of the corrosion resistance of stainless steel.[/sapphire_textBlock][sapphire_textOverlayBlock image=”460″ heading=”Sapphire’s One-Stop Suspension Solution” button_text=”Read more” button_link=”url:https%3A%2F%2Fwww.resi.build%2Fpost%2Fsapphires-one-stop-suspension-solution” double_height=””]Learn more about how Sapphire splits out their anchors and stubs to create a safer connection.[/sapphire_textOverlayBlock][/vc_column][/vc_row][vc_row width=”70″ background_image=””][vc_column css=”.vc_custom_1707736247028{padding-bottom: 10px !important;}”][sapphire_textBlock]Using material like timber or concrete is not a wise choice as the material cannot endure time, nor the elements. We’ve seen in recent months that timber will degrade over time – this fundamentally misses the spirit of construction design and management (CDM) regulations. Using a material that will maintain its integrity for the entirety of its lifespan should be a priority. With aluminium, this can be achieved with relative ease as it does not rust or degrade over time.

Finally, the material choice should always be non-combustible. In the UK this is mandatory on taller buildings under Part B of the Building Regulations. In other markets where this is not mandatory, the guidance should still be followed to ensure the absolute safety of the end-user. By using non-combustible materials, unnecessary fire risk or spread can be avoided.

Construction methods

The next step to ensuring balcony safety is through the methods of construction. Thanks to modern methods of construction (MMC), construction is more flexible and innovative than ever so safety can be more readily assured, so long as the correct methods are used.

Connecting a balcony mechanically is the simplest way to ensure connection safety. Historically, adhesives have been used a lot on building façade to stick components together, but this can be a risk. At Sapphire, we choose to mechanically fix components to the building façade through arm connected with stainless steel bolts, which do not lose their structural integrity like adhesives could and are easier to control the correct torque settings have been achieved, whereas an adhesive done correctly can be difficult to confirm, is more dependent on competence and expierience of the applicator and may become lose over time or in extreme heat or cold.

The competency of process and people should also be considered here. Like cars, controlled manufacturing envrionments with the right processes mean that prefab balconies should be inherently safer. Offsite manufacture must be tightly controlled with safety procedures and quality control in place at every step of the process. Throughout our history we have continually reduced the dependence of site labour and site conditions by designing more of the production to be carried out in factories. We manufacture our balconies offsite, monitoring each stage of the production with our Passport® app. We have also introduced a learning management system (LMS), which allows us to monitor and ensure the training, competency and compliance of all our workers. This enables a single balcony to then be traced back to which factory, which date, which operative and what thier training records were at that point. The passport app has continually been expanded and advanced to enable the collection of more and more data and imagery of the production process.

Finally, minimising the dependence on an individual’s competency is crucial for balcony safety. At Sapphire, we believe in ensuring that our staff are competent and continually learning, but this alone is not enough. High dependence on the skill of a single labourer is a potential risk area and so is assembly done on sites where there is other factors which could influence. By simplifying the product junctions and making sure the system itself is as risk-averse as possible, we further avoid the risk of workers relying on a single staff member’s competency. As an example, by having all welds double-checked independently and by using witness marks on connection bolts, we can quickly determine if bolts have been torqued correctly or if key connections have been tampered with, both measures which support the delivery of product which is not only of good quality but is also up to the high safety standard our clients and Sapphire expect.

Fire risk

As mentioned above, fire risk is an important consideration for balcony manufacturers as well as construction developers. To avoid another disaster like that at Grenfell Tower in 2017, we must take steps to mitigate against fire spread. This can involve better choice of materials and discouragement of fire risks for our end-users.

Material selection is key. We spoke with Kevan Brelsford of the Manchester Fire & Rescue team and he summarised the need for better material selection. Using flame-retardant, non-combustible furnishings is crucial. The need for this may seem obvious in a post-Grenfell world, but it needs to be reiterated. Furthermore, minimising ignition sources can be the difference between safety and danger as “more or less anything will burn in the right circumstances”, so reducing the opportunity for fire to start and/or spread is key.

Watch the full video with Kevan Brelsford speaking on behalf of the Manchester Fire & Rescue team to learn more about fire risk:

 

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Drainage methods

Water ingress has been a key challenge in most markets the balcony markets we work in globally.

In markets like New Zealand, we’ve seen the ‘leaky homes’ crisis, where timber-framed homes built primarily in the 1990s were not properly protected against the weather. These drainage problems have in some instances made the timber framing structurally unstable and so unfit to live inside. We’ve seen similar issues in the Canadian market and so the need for structurally sound homes, protected against water ingress, is key.

The key principle of drainage is that the nearest point of water collection needs to be as far from the building threshold as possible. Collection of water should, in no circumstances allow for a build-up. Finally taking water away from the building is much better principle than back towards a building.

To mitigate against this, materials should be considered, as well as direction of drainage and number of drainage points.

Corrosion-resistant materials such as aluminium should be used. Timber should never be used as a drainage material due to its susceptibility to rotting. Draining away from the building in 400mm sections is a method that Sapphire uses – our edge draining solution (as it is known in balcony standard BS 8579:2020) uses multiple points of drainage through integrated soffits in order to disperse water efficiently and safely without the need for fixed rear drainage pipes.

Maintenance

Balcony maintenance should be simple to carry out, regular and thorough.

A balcony left to fester amongst the elements, no matter the material used to construct it, can be at risk of the averse effects of ageing. Maintenance should therefore be carried out whenever necessary and, where possible, regularly scheduled.

Balconies should be designed with maintenance in mind. Urgent maintenance should not require scaffolds to be set up and so balconies should be designed to be maintained from the apartment they belong to.

At Sapphire, we design our balconies in this way. As an example, a balcony can have its decking raised to view the soffits below, meaning essential maintenance can be carried out both quickly and thoroughly to avoid incidence.

Conclusion

Understanding the risk that comes with construction and ongoing use of balconies is of the utmost importance. Balcony manufacturers and suppliers must make sure their products are safe on delivery, safe to install and safe for the end user over its entire design life.

We use aluminium construction due to its structural rigidity, improved safety aspects when compared to a traditional concrete alternative, integrated drainage system to reduce risk of water ingress, its non combustible properties and the wide variety of secure connection possibilities that can be chosen depending on the project at hand.

When asking the question; “is my balcony safe?” – it takes analysis of all risk areas, research and development and a competent team to supply an answer. If you are moving into a new property and you are lucky enough to have a Sapphire balcony, we certainly believe that our ethical approach to balcony design combined with our rigorous testing regimes and quality systems do mean that you are in a safe pair of hands with Sapphire.

To learn more about making your balcony safe, we’ve provided links to whitepapers, CPDs and articles published by Sapphire below.[/sapphire_textBlock][sapphire_textOverlayBlock image=”11006″ heading=”Balcony Fire Safety Whitepaper” button_text=”Download” button_link=”title:Fire%20Safety%20Whitepaper” double_height=””]Regulations, research and testing, available in our whitepaper.[/sapphire_textOverlayBlock][sapphire_textOverlayBlock image=”13767″ heading=”Balcony Fires CPD” button_text=”Request now” button_link=”url:http%3A%2F%2Flocalhost%2Fbalconies%2Fknowledge%2Fcpd-presentations%2Fbalcony-fires-cpd%2F|title:Balcony%20Fires%20CPD” double_height=””]Request our balcony fires CPD – learn about common causes and reduce risk.[/sapphire_textOverlayBlock][sapphire_textOverlayBlock image=”12657″ heading=”Balcony Drainage” button_text=”Read more” button_link=”url:http%3A%2F%2Flocalhost%2Fbalconies%2Four-product%2Fframe-deck-soffits%2Fsoffits%2Fbalcony-drainage%2F” double_height=””]All you need to know about balcony drainage.[/sapphire_textOverlayBlock][sapphire_textOverlayBlock image=”13768″ heading=”Balcony Materials, Maintenance & Lifespan” button_text=”Read more” button_link=”url:http%3A%2F%2Flocalhost%2Fbalconies%2Fknowledge%2Fmaterial-maintenance-and-sustainability%2F” double_height=””]Learn more about how to choose balcony materials on our dedicated page.[/sapphire_textOverlayBlock][/vc_column][/vc_row][vc_row width=”70″ background_image=”” el_id=”” el_class=”” css=””][vc_column][vc_raw_html]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[/vc_raw_html][/vc_column][/vc_row]

Interesting Innovations: Balcony Drainage

Posted on by Sajjad B

[vc_row width=”70″ background_image=””][vc_column][sapphire_textBlock]Adding a balcony to a building is often considered to be adding ‘jewellery’, making the building look more elegant and high-profile whilst also giving the residents of the apartments an essential outdoor space to relax. However, by adding outdoor space to a residential building, the need for proper drainage becomes essential. Whether drainage is needed because of spillages or heavy rain, the liquid needs to be disposed of somehow. Without proper drainage, the base of the balcony could suffer water damage, the concrete could crack or the metal could corrode.

With Sapphire, interesting innovations in drainage are possible.

The drawbacks of fixed pipe drainage

Traditionally in countries such as the Netherlands, balconies have been cast in concrete and fixed to a building’s façade after waterproofing details have been added. This is a tried and tested, though largely time-consuming, method of balcony connection and is common across cities like Amsterdam and The Hauge.

Concrete balconies require drainage fixed to the balcony itself, letting the water run from grates at the rear edge of the balcony into pipes that run down the side of the building. This traditional solution can be unattractive and with the addition of angling the floor towards the drainage area of the balcony, it can even take extra time in the manufacturing process.

An interesting innovation in drainage – controlled edge drainage

Over the past ten years, Sapphire has developed a smart soffit approach for the ceilings on the underside of balconies that are divided into small sections, allowing liquid to drain evenly along the length of the balcony. This design has been successfully adopted in many projects across the UK and Ireland in high-rise residential buildings up to 30 storeys tall.

The smart ceilings provide a soffit drip tray, known as ‘controlled edge drainage’, and are fitted to the underside of all aluminium Sapphire balconies as standard. The rain and other liquids flow through the balcony decking and drain forward, with the ceilings angled in such a way that avoids draining onto the balcony below. Controlled edge drainage also leads to aesthetic benefits as no rear pipes are needed on the building.[/sapphire_textBlock][sapphire_cta background_colour=”Dark Blue” custom_background_image=”11796″ heading_colour=”White” heading=”Soffits – Controlled drainage” text_colour=”White” button_colour=”Green” button_text=”Read more” button_link=”url:http%3A%2F%2Flocalhost%2Fbalconies%2Four-product%2Fframe-deck-soffits%2Fsoffits%2Fsoffits-controlled-drainage%2F” alignment=”Right”]Read more about controlled drainage and how we use soffits to drain water from the balcony.[/sapphire_cta][/vc_column][/vc_row][vc_row width=”70″ background_image=””][vc_column][sapphire_textBlock]

What are the costs associated with drainage?

Thanks to Sapphire’s innovative approach, drainage doesn’t need to be expensive and can even extend the lifespan of a balcony.

Free-draining balconies (or balconies without drainage solutions) are the lowest in cost but come with the safety issue of water draining onto balconies below or not draining correctly at all. Adding a form of drainage such as a drip tray provides a relatively cost-neutral approach to drainage, whereas a rainwater pipe, for fixed rear drainage, can typically add a further 25% to the cost of a project and may make the construction significantly more complex.

At Sapphire, we recommend all balconies should use soffit drip trays, and our smart ceiling solution is added to our aluminium balconies as standard, meaning the cost of a drainage solution is factored into the design from the very start.

Drainage is an important part of balcony design and should be considered from the very start of a balcony project. Whilst free drainage is the cheapest option initially, the lack of proper maintenance could lead to severe water damage at a later point and could have an adverse effect on the continued cost of the balcony. Your project could benefit from Sapphire’s aluminium balconies with smart ceilings included for controlled edge drainage, so consider this option from an early stage.

Learn more about drainage by downloading our whitepaper here:[/sapphire_textBlock][sapphire_cta background_colour=”Dark Blue” custom_background_image=”226″ heading_colour=”White” heading=”Balcony Drainage Whitepaper” text_colour=”White” button_colour=”Green” button_text=”Read more” button_link=”url:http%3A%2F%2Flocalhost%2Fbalconies%2Fknowledge%2Fwhite-papers%2Funderstanding-balcony-drainage-strategy-and-methods-whitepaper%2F” alignment=”Right”]Download our whitepaper on balcony drainage to understand more.[/sapphire_cta][/vc_column][/vc_row]

Drainage and BS8579

Posted on by Sajjad B

[vc_row width=”70″ background_image=””][vc_column][sapphire_textBlock]The new standard for balcony design, BS8579, was introduced in August of 2020. While the guidance is not mandatory, it clears up differences between balconies and terraces, open and enclosed balconies and provides direction on designing for fire, accessibility, and drainage solutions.

Balcony Drainage

Before the BS8579 was introduced, a lack of BS/EN standards meant that The National House Building Council (NHBC) was often quoted for balcony drainage. The NHBC provides guidance (section 7.2.22) on pitched roofs, stating that any balcony with a floor area of 6m2 or over should have drainage provided as standard. However, this guidance also states that consideration should be given to drainage for smaller balconies and these balconies should not have a finished fall of less than 1:80. Furthermore, an overflow outlet should be provided either through parapet walls or perimeter upstands to prevent flooding in the event of a blocked outlet.

To prevent water build-up, the decking installed on the balcony should sit at least 50mm above the threshold of the water collection point.

Summarily, efficient, effective, and elegant balcony drainage must prevent the accumulation of water. The stagnation of water can promote poor sanitation and damage the structure of the building. BS8579, the new standard, advises designers to incorporate some form of controlled drainage so water does not enter the building.

Accessible Balcony Threshold

British Standards require that pre-manufactured balconies should have a low kerb of 25mm at a minimum below the underside of the door sill to act as an overflow.

Sapphire Balconies have been at the forefront of balcony drainage solutions in recent years, with our Glide-On™ Cassette® balconies all complete with positive edge draining, requiring no piping at any point in the installation or maintenance of the balcony. Please note that Andrew Parsons, Technical Director at Sapphire Balconies, is a part of the committee which contributed to the BS8579 standard.

Piped drainage Vs Controlled Draining

The right drainage solution for a balcony can depend heavily on the method in which it was manufactured. An aluminium balcony and a concrete balcony have different requirements to drain effectively, efficiently, and elegantly.

For concrete balconies, rear piped drainage is the ideal solution. As concrete does not allow water to pass through into a soffit, drainage from higher in the base is needed. Rear pipe drainage manages the water flow, taking it to a gutter at the rear end of the balcony, and flowing it down into a rainwater pipe. It should be further noted that as per British Standards, piping must be implemented if the balcony projection is over 2.5m from the façade.

Alternatively, a balcony can use controlled edge drainage. Controlled draining balconies manage the flow of water and flow it towards the front edge of the balcony. The water is dispersed evenly along the front edges of the fascia and drips off through small gaps at the edge of the soffits. There is a misconception that controlled edge drainage will increase the accumulation of water at ground level. Adding balconies with controlled edge draining means the same amount of water being drained but less water flowing down the façade to the ground. The same amount of ground-level drainage will suffice as the water is being controllably dispersed.

With controlled drainage, there are two notable considerations. Firstly, ground-level drainage must be considered. Any water drained from a balcony must be further drained from ground level and not allowed to stagnate. Secondly, any water drained from over the entrance of a building must be drained to avoid becoming a nuisance to pedestrians.

Each solution can be particularly effective if used correctly and with the correct design considerations in place, following the new BS8579 standard can be simple. For more information and to understand the difference between piped and controlled edge draining, please consider watching the video below:[/sapphire_textBlock][/vc_column][/vc_row][vc_row width=”70″ background_image=””][vc_column][sapphire_videoBlock video=”” video_url=”https://www.youtube.com/watch?v=noo0Gq9TEuk”][/vc_column][/vc_row]

Drainage matters

Posted on by Sajjad B

[vc_row width=”70″ background_image=””][vc_column][sapphire_textBlock]

Drainage matters

Sapphire Balconies, a leading UK manufacturer of balcony solutions, considers the most frequently asked questions when it comes to designing a drainage solution for a balcony project.

Different balcony structures have different drainage requirements. Concrete balconies, for example, tend to be treated like a flat roof and are normally finished with a waterproof membrane, drainage outlet or overflow pipe.

Building Regulations

Any water collecting on a balcony deck, either from rainfall or from watering container plants, should be addressed in the design of the balcony to ensure it doesn’t drip onto the balcony below. With this in mind, drainage of balconies is covered by Building Regulations and industry guidance. Approved Document H3 of the Building Regulations requires adequate provision for rainwater to be carried from the roof of the building but does not state whether balconies are considered part of ‘the roof’.

Industry guidelines

NHBC guidance (section 7.1 ‘Flat roofs and balconies’) states that balconies shall have adequate rainwater disposal to a suitable outfall but does not go into detail about drainage options.

Given the lack of clear guidelines, Sapphire strongly recommends that Building Control and NHBC inspectors are consulted at an early stage of a balcony project to ensure the proposed solutions meet with their approval.

Decision factors 

Having considered the legal requirements, let’s take a look at the main issues and solutions when choosing a balcony drainage system.

Firstly, there is the question of cost. Free draining balconies are the lowest in cost. The addition of a drip tray typically adds around 10%. Incorporating positive drainage to a Rain Water Pipe (RWP) typically adds a further 25% and also makes the construction significantly more complex.

Appearance is another important consideration. The rather ‘industrial’ look of free draining balconies can be improved by adding a soffit/drip tray. Balconies draining to a RWP need to be deeper to accommodate pipework so can look chunkier

Safety must also be considered in any decision. The risk of hot liquids falling through the balcony deck onto residents below can be reduced by a drip tray or RWP.
Last, but not least, there is the issue of façade staining. The use of positive drainage is likely to reduce the risk of water running down the façade and causing staining.

Decking options

Another question we are often asked at Sapphire is whether the choice of balcony deck has an impact on drainage and the answer is yes. Grooved decking boards are commonly used as a surface. Experience has shown that the majority of rainwater falling on the decking will run along the grooves and drip off the end of the board. It is, therefore, better to run decking parallel with the building line, otherwise there can be a substantial amount of water dripping off adjacent to the façade, increasing the risk of staining or water penetration.[/sapphire_textBlock][/vc_column][/vc_row][vc_row width=”70″ background_image=””][vc_column][sapphire_contentLink order=”Image left / content right” image=”7433″ heading=”Drainage Whitepaper” button_text=”Download Drainage Whitepaper” button_link=”url:http%3A%2F%2Flocalhost%2Fbalconies%2Fknowledge%2Fwhite-papers%2Funderstanding-balcony-drainage-strategy-and-methods-whitepaper%2F|title:Understanding%20balcony%20drainage%20strategy%20and%20methods%20%E2%80%93%20whitepaper|target:_blank”]Detailed whitepaper focused on key considerations and technical guidance for balcony drainage[/sapphire_contentLink][sapphire_contentLink order=”Content left / image right” image=”467″ heading=”Balcony Drainage Requirements” button_text=”Explore Drainage Requirements” button_link=”url:http%3A%2F%2Flocalhost%2Fbalconies%2Four-product%2Fframe-deck-soffits%2Fsoffits%2Fbalcony-drainage%2F|title:All%20you%20need%20to%20know%20for%20balcony%20drainage|target:_blank”]Explore the key requirements for balcony drainage[/sapphire_contentLink][/vc_column][/vc_row][vc_row width=”70″ background_image=””][vc_column][sapphire_textBlock]

Other Resources

[/sapphire_textBlock][vc_row_inner][vc_column_inner width=”1/2″][sapphire_cta background_colour=”Green” custom_background_image=”” heading_colour=”Dark Blue” heading=”Controlled Drainage on Balconies” text_colour=”Dark Blue” button_colour=”White” button_text=”Understand Controlled Drainage” button_link=”url:http%3A%2F%2Flocalhost%2Fbalconies%2Four-product%2Fframe-deck-soffits%2Fsoffits%2Fsoffits-controlled-drainage%2F|target:_blank” alignment=”Left”][/sapphire_cta][/vc_column_inner][vc_column_inner width=”1/2″][sapphire_cta background_colour=”Green” custom_background_image=”” heading_colour=”Dark Blue” heading=”Drainage & BS8579 Standard” text_colour=”Dark Blue” button_colour=”White” button_text=”Explore Drainage Requirements for BS8579″ button_link=”url:http%3A%2F%2Flocalhost%2Fbalconies%2Findustry-news%2Fdrainage-methodology-bs8579%2F|title:Explore%20Drainage%20Requirements%20for%20BS8579|target:_blank” alignment=”Left”][/sapphire_cta][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row]