"roofing membranes"

Truss roof rafters and ceiling joists are typically spaced either 400mm, 450mm or 600mm apart. Given that the joist is normally 50mm wide, this gives a fairly small opening width for your loft hatch and ladder. However, there are still a wide variety of options to consider. For example, space saving concertina loft ladders, are easy to operate, providing robust and durable access to an attic. Made-to-measure folding wooden loft ladders, such as the new Quadro, are available for widths of 550mm and offer minimal protrusion in the loft space above. Visit our website for more information.

Westerland and Moorland, BBA certified fibre cement slates from Cembrit, have helped achieve a Code for Sustainable Homes and a BREEAM ‘Very Good’ rating for a newly built £30 million retirement village in Oxfordshire.Built by BAM Construct UK and due for completion in December 2016, the project is built in an attractive, traditional style which is complemented by Cembrit’s Westerland and Moorland slates. Based in Hertfordshire, BAM Construct UK worked with roofing specialist Attleys Roofing Ltd on the project.

When Make Architects needed a waterproofing solution for their latest project in the City of London they turned to IKO PermaTEC hot melt. Waterproofing such an expansive and complex roof has its particular challenges and required robust and reliable detailing. The choice of waterproofing was to perform for a minimum of 30 years, be cost effective and also contribute towards the building’s design stage BREEAM Excellent rating.

This is a metal roof coating & refurbishment project using Liquasil's BBA Approved Metalseal 20. The project involved removing an existing cut edge corrosion treatment and re-treating with Liquasil SWT Corrosion Primer, followed by two coats of Metalseal. The whole roof was then coated with Metalseal 20 to provide long term protection against fungal growth and weathering. The unique 10 year, single-point latent defects insurance guarantee was issued at the end of the project. For details, speak to our building surveyors on 0121 709 5352

Gent Sint-Pieters railway stationCHALLENGE Gent Sint-Pieters, the main railway station in Ghent, is undergoing a spectacular metamorphosis today. The listed main building, constructed for the 1913 World Exhibition, has to remain untouched. Behind the old building however the platforms, waiting rooms and the central passengers corridor are being entirely refurbished. Architect Voncke’s objective was to create a pleasant atmospheric site with a 35,000 sqm open and attractive central hall, broadened and completely covered platforms and renovated rails. Functional, well-designed and above all spacious! As the 12 rail tracks had to stay on ground level, the passengers alley was excavated to a lower level under the railroad tracks. This necessitated permitting considerable daylight to enter the underlying levels.SOLUTION Transparent canopies, featuring large glass sections and translucent floors were all designed with this purpose in mind. To gain even more light the architect chose RENOLIT ALKORBRIGHT for waterproofing the platform canopies. The six long rectangular platform blocks, differing in height, are interconnected and make one large roof. The white highly reflective RENOLIT ALKORBRIGHT membrane on top of the construction reflects the daylight through the high side windows. A clever way to add extra day-light to the underlying areas. 

The brief for this project was to design, supply and install a bespoke and sympathetic waterproofing solution to a Grade II listed, commercial structure with an impractical damp basement.Delta Registered Installers, MacLennan Waterproofing worked closely with the Principal Contractor, HB Projects to achieve a Grade 3 habitable space whilst preserving this historic structure.The Co-op shop in Petworth Village, provides the local community with everything they need, whether its household essentials or a place to meet friends.The site incorporates two Listed Buildings, including part of a Listed Church. The store applied for listed building consent to reconfigure its ground and basement floors, to increase the retail floor space and improve the functionality of the store.When designing a waterproofing/damp proofing solution in a historic building or a structure of architectural interest, additional design considerations should be employed during the design stage to maintain preserve aesthetic and structural integrity of the structure/building. The waterproofing design should be sympathetic in application whilst offering a robust solution.Care consideration should be applied when specifying products to ensure they are ideally suited for meeting the complexities of listed building requirements.

Delta Registered Installers Timberwise (UK) Limited were called upon to offer a waterproofing design to this Grade II Listed property to meet the requirements of BS 8102:2009 to achieve a dry habitable living space, defined as a grade 3 environment.

Hydrostop AH-25 liquid roofing was chosen as a better alternative to built-up roofing for installation to a new build Surrey County Council office development. The Hydrostop AH-25 system was applied over a concrete substrate with a bituminous vapour control layer with Eurodeck liquid roofing board and cut to falls insulation.

Architect: Scenario Architecture. This beautiful Victorian villa received an innovative green-roofed extension full of natural light thanks to IDSystems installed bifold doors, gable end glazing, rooflights, window and door. The challenge for Scenario Architecture was to design an extension that was filled full of natural light, took into account the changing floor levels of the property. Under the pitched roof, the gable end glazing has been designed to perfectly match the profiles of the SUNFLEX SF75 bifold doors, whilst the inclusion of a single access door allows the extension to angle away to create a larger kitchen/dining area.

Editorial on dry fix roofing and the factors to consider when making a product choice.

Project: Surespan designed and manufactured these huge electrically operated sliding glazed roof hatches also provide free airflow of 7m² for smoke ventilation!These bespoke designs were part of a redevelopment on Great Portland Street in London. The covers were 4610 x 1955mm and featured an electrically driven opening motor.Product:The covers provide 7m² free airflow (As it is sliding there are no obstructions to the ventilation) according to approved document B (fire safety) paragraph 5b diagrams C.7.The glazing features laminated and heat-strengthened low iron glass to L40.A further fixed rooflight was also supplied to the size of 4935mm x 1955mm, the thermally broken multi-pane rooflight provides natural daylight

SubFloor Outdoor Flooring was used to help renovate and raise a 650 m² roof into an outdoor terrace in Västerås, Sweden.This was built on top of the existing roof felt and used high-quality pressure impregnated wooden joists to create an even surface, level with the rest of the building. The joist and screw system allows for quick and easy assembly so that the floor can reach the desired height.Products:Pre-treated Wooden Joist 45x70x3600 mmSubFloor Screw 300 mmSubFloor Screw FootHeight Variation: 90 - 339 mmJoist separation: c/c 300 mmSystem Weight - c/c 300 mm: 10.72 kg/m²Materials:Pine T0-C24Fibre-reinforced polypropylenePolyamidePoint Load Limit (50 x 50 mm):Load next to screw over joist edge - 21.74 kNLoad between screws over joist edge - 16.43 kN

No timber was allowed as part of the new refurb to conform to FM Global (Airbus Insurers) regarding system fire rating. IKO recommended an overlay on the existing deck, which complied with all the latest British Standards and Regulations. IKO Mach One System was chosen as it provided a flame-free System. Where detailing was difficult IKO Polimar EC/UV System was used. The roof refurbishment also included the installation of smoke vents, associated smoke control panels and accessories.

The Polden tile has been used on various sites in Scotland as a slate solution. With its riven finish and mock bond the tile gives a true natural look but still has all of the benefits of a concrete interlocking tile.

An office building in Manchester has a large roof terrace area that was incorporated into the building wide refurbishment. They wanted to increase the usability to the terrace by adding outdoor furniture to encourage employees to use the space for interacting and getting fresh air. The Parallel42 benches were chosen due to their flexibility and contemporary look which would complement the terrace space and provide ample seating. The Benches were installed free standing for ease of positioning and can be rearranged as required. EY now has a usable terrace area that is enjoyed by many of the company’s employees.

One of our latest projects was for a school in Barking, East London. The school required new waterproofing on their roof and chose OptiTec because we have a range of suitable products to choose from, offering excellent durability and longevity at a great price.Specification – Systems UsedFor this project, a long-lasting system was required with a Broof T4 fire classification for safety. Our technical team advised the OptiPlan-FB (PVC Single Ply) system for this project as it met the brief safety-wise, but it’s also excellent value for money over a large area.The OptiPlan-FB system is a fibreglass reinforced, fleece-backed synthetic waterproofing membrane made from premium quality PVC-P, offering exceptional resistance to weather and UV rays. A great benefit of this system is that it can be installed year-round due to having excellent flexibility in cold temperatures.This system was installed by an OptiTec Approved Contractor to ensure the highest quality of fitting with the option for a labour and materials guarantee if required.Challenges PresentedThere were no real challenges presented during installation and everything ran smoothly. We have a technical team on hand at all times to provide support and advice where required so we can always overcome any challenges presented in the best way possible.ResultsThe results of this project are fantastic and the client has expressed their satisfaction with the professional installation of the system and the overall finish.

Armourplan PVC and Recticel Insulation by SIG Design Technology were selected for a 12,000 m2 roof to a bottling plant in a rural location on the outskirts of an historical Derbyshire spa town, known as Project Merlin. The FMCG company chose to build the new facility away from the site of the natural spring, piping the water some two miles out of town to this green field bottling and distribution site.

The former ToysRUs premises in Luton required complete refurbishment and part of the project involved renovation of the metal roof. Liquasil's BBA Approved Metalseal 20 system was specified because it includes the advanced, SWT Primer to treat cut edge and spot corrosion in-situ. The metal gutters were lined with Liquasil's Gutterseal, seamless liquid gutter lining system. Upon completion of the metal roof coating project, the unique, Liquasil Latent Defects Insurance Guarantee was issued. The Liquasil guarantee includes cover for Professional Design, meaning that you can specify Liquasil products with 100% confidence.

Our premium granite TerraPave® flagstones were a perfect choice for this scheme at one of London’s foremost rooftop cocktail bars and pizzerias. Skylark Roof Garden, located on Kingdom Street, sits on the 10th floor of Paddington Central, offering incredible views overlooking the beautiful Notting Hill, on the banks of Little Venice. For this project, a combination of Pedestals and TerraPave® flags were utilised. The incorporation of Pedestals (stools on which the flags were laid) , meant no base was required. The depth of TerraPave® flags is calibrated as part of the manufacturing process, delivering exceptional dimensional accuracy which in turn delivered consistent levelling across the terrace. Project architects, Allies and Morrison selected our TerraPave® Flags, in Rimini and Milano Ground due to their rich, distinctive styles and impressive durability in highly pedestrianised areas. These flags are produced with locally-sourced, natural aggregates instead of pigments meaning their unique colouration won’t fade. TerraPave® also offers a cost-effective, and practical alternative to traditional stone paving. The £80m Paddington Central scheme was completed built by Wates Construction and designed by Allies & Morrison. Some of the impressive project’s additional features include London’s highest basketball court, an external glazed stair tower, and a public colonnade around the retail space on the ground floor.

LAMILUX designed, supplied and installed both the supporting steelwork and atrium glazing to illuminate the central zone of the venue with natural daylight. Structural calculations were generated to ensure that the steelwork, which was assembled from five sections, could withhold the weight of the high spec glazing used. 76 fixed panes, walkable for maintenance and weighing 65kg per m², create the 20m x 9m wide unusual curved glass roof with wall abutment detail. 3 anchor points, which forms part of the rooflight system, were installed so that maintenance personnel are able to fix their safety harnesses onto the anchor points.

Sliding-Over Fixed Rooflight Maximises Light In Mansard Roof Extension Case Study

ProjectSurespan designed and manufactured these huge electrically operated sliding glazed roof hatches also provide free airflow of 7m² for smoke ventilation!These bespoke designs were part of a redevelopment on Great Portland Street in London. The covers were 4610 x 1955mm and featured an electrically driven opening motor.Product: The covers provide 7m² free airflows (As it is sliding there are no obstructions to the ventilation) according to approved document B (fire safety) paragraph 5b diagrams C.7.The glazing features laminated and heat-strengthened low iron glass to L40.A further fixed rooflight was also supplied to the size of 4935mm x 1955mm, the thermally broken multi-pane rooflight provides natural daylight

This is an example of an asbestos roof cleaning and coating project using a closed box pressure washer and the BBA Approved Asbestoseal asbestos roof coating system from Liquasil. Specify Asbestoseal with confidence, as it's the only BBA approved system on the market for this purpose. It also comes with the unique Liquasil Latent Defcts Insurance Guarantee, including cover for Professional Design. Need more information? See our NBS specification or call 0121 709 5352. Liquasil is owned and run by Chartered Building Surveyors. We will help you with your specs!

The new generation of M-Tray® modules were used on this office building in Poklington, Yorkshire. This project was in the heart of the Vale of Yorkshire, within and Area of Outstanding Natural Beauty and planning sensitivities dictated a green roof was needed on the office building. The clients wanted the existing farm buildings, which had been converted into offices and storage space, to blend into the hillside with the structures having the very lowest impact on the surrounding countryside.The timber framed building meant a low weight solution was required so the 100mm deep pre-grown modules were ideal.

A three year £24 million programme of works to repair and repaint the roof structure to Bristol Temple Meads railway station is featuring the use of the ZEUS Horizontal fire barrier system from FIREFLY™: employed to enclose a series of shallow arch scaffold beams or ‘cassettes’ that span the tracks, thereby protecting the workforce from any potential train fire as they use the access deck above.

The NHS Estates Team required a new office space and workshop area and proposed the refurbishment of an existing building.Systems in useHyranger®Starcoat® PMMAOverviewAxter Ltd were instructed by William Gough & Sons Ltd to produce a design for six roof areas, following a site survey report. The project included a mixture of new build and refurbishment areas, comprising of various systems and design requirements. This included a cut to falls insulation design to comply with Part H and BS 6229:2018. Roof A, the focus of this case study, had a series of convex or ‘barrel roofs’, requiring bespoke detailing and careful design to achieve robust detailing and the required U-value.The project value was circa £1 million. This included all building works and a strict budget for the roofing package, which was achieved. The programme for the works was 16 weeks and completed in Autumn of 2022, to the required deadline.The successful project was also nominated for a National Federation of Roofing Contractors (NFRC) award 2023.ChallengesAxter were appointed at RIBA Stage 2 to undertake site surveys and work alongside the Principal Designer as Designer under the Construction Design and Management Regulations 2015.The existing asphalt had shown signs of cracking and blistering, and the outlets were damaged from vegetation growth from a lack of maintenance. New outlets were installed with leaf guards, allowing free flowing water whilst preventing blockages.The proposed office section of the works required thermally upgrading to comply with Building Regulations: Part L. The U-Value requirement was 0.18W/m2K which could be achieved with a 120mm PIR flat board. Due to the curved profile of the roof, installing the insulation below deck level was considered. However, due to an inadequate ceiling height this was disregarded.Furthermore, this would have resulted in the development of interstitial condensation. Further design solutions had to be considered. To bend a 120mm board would have required multiple cuts to the insulation so the decision was made to split this into two thinner boards to achieve the radius more easily.When split into two layers the requirement changed to 2 x70mm boards (140mm total) as worked out using U-Value calculations by the in-house design team at Axter. A timber hard edge was introduced to abut the insulation at the building perimeter to separate the façade and the main field area.Systems and productsAxter’s Hyranger multi-layer RBM system was used across all six roof areas. The system is fully BBA and BRoofT4 compliant, and achieves a guarantee period of 20 years. For this project, Axter’s Goldshield Guarantee was chosen, which covers materials, workmanship and design liability. This was overseen on site by Axter’s Quality Assurance team, who audited the project inclusive of the installation, safety and general management of the roofing works.Axter Starcoat PMMA was used as a cost effective solution to coat the copper fascia and provide a fresh and seamless look to the exterior of the building.SolutionsThe Axter Hyranger multi-layer RBM system was installed using traditional gas driven torches to fully bond the (AVCL) Air and Vapour Control Layer and cap sheet layers. The underlayer was installed over a tissue faced PIR and therefore needed to be self-adhesive in order to reduce the risk of fire, complying with NFRC Safe2Torch guidelines. A cold applied Starcoat PMMA liquid was installed to the façade to achieve a seamless and cost-effective upgrade.The Axter Quality Assurance Team regularly attended site and were in constant communication with the appointed Axtershield Installer, Empire Roofing operatives, to ensure that the system was being installed correctly and to the expected standards in order to achieve the Goldshield guarantee required by the client. To achieve the guarantee level, all materials and workmanship had to be installed as per the Axter specification.The site agent from the main contractor was also regularly on site to oversee the project and ensure that deadlines and timescales were being achieved to keep the build on target for completion. The installation of the multiple roof areas was achieved to exceptional standards leaving the client very impressed with the workmanship.AcknowledgmentsWilliam Gough & Sons Ltd were very impressed with Axter Ltd on our first scheme with them at George Eliot Hospital in Nuneaton. The requirements of the scheme, which included a complex barrelled roof were investigated on site early in the design phase of the project and Axter’s recommendations were swiftly proposed and agreed with the client’s Architect. Once the design requirements had been established one of Axter’s approved installers were employed by us to very successfully deliver the scheme. The 20 year Goldshield guarantee provided for the Reinforced Bituminous Membrane system offered peace and mind to our client. Chris Hinton, Senior QS, William Gough & Sons

If there is one thing that characterizes Scotland and touches all its visitors, that is its natural surroundings and historical buildings, which still retain their original charm. So, as the world leader in natural slate, we are proud that our slates have been chosen to renovate one of these heritage buildings: the Renfrew Town Hall and Museum. THE BEST CHOICE FOR HERITAGE BUILDINGS As part of a refurbishment programme, The Renfrew Town Hall roof has been recently renewed with our natural slate Heavy 3. This slate has been the perfect choice to keep its original appeal of tradition and heritage.

Easton Square, an exclusive development of four bespoke, luxury 6-bedroom houses, features CUPA 12 R Excellence roofing slates. The product was selected for its superior qualities including its adaptability, longevity and polished finish. The exclusive Langton Homes development is set in large private grounds in Great Easton. Each property features over 5,500 square feet of accommodation and has been tailored towards the individual needs of each occupier. CUPA 12 slate has been used across all four Easton Square dwellings including the properties’ associated outbuildings and garages.

Due to the bustling activity of our client’s builders merchant business, we recognised the need to enhance the accessibility and user-friendliness of their commercial unit. The existing setup featured a pedestrian entrance alongside a roller shutter entrance designated for goods in bay, which posed challenges in accommodating the high traffic flow and meeting customer expectations.To address these concerns, we proposed a comprehensive solution that would transform the customer entrance into a wider, more inviting space. A framed shop front system was strategically installed just inside the loading bay entrance, creating a seamless transition between the outdoor and indoor spaces. To ensure continuity and functionality, a short canopy roof was added, along with a heavy duty brush seal to bridge the gap to the roller shutter entrance.The focal point of our solution was the integration of a heavy duty commercial grade silent automatic bi-parting sliding door system. This innovative addition not only enhanced user-friendliness for customers but also facilitated rapid opening and closing, crucial for a busy builders merchant environment. By combining functionality, convenience, and efficiency, we successfully transformed the customer entrance into a welcoming and efficient gateway that catered to the needs of our client’s thriving business.

In 2014 discussions took place between IKO and Architect for the property, over the possibility of renewing the mastic asphalt roof coverings with an IKO Permaphalt Polymer Modified Mastic Asphalt System. During 2015 this process took place with the work being undertaken by Knight Asphalte, one of IKO’s Approved Contractors. During the works some 35 tonne of IKO Permaphalt was installed and due to IKO’s commitment of supplying Carbon Neutral Mastic Asphalt we are able to calculate the impact this has on the population.

Glazing Vision rooflights were used in the re-construction of this mews house situated in the prime real estate and conservation area of Mayfair, London. The building is an exceptional example of stunning architecture and elegant, contemporary interiors. Whilst adding a majestic character to the mews itself with its dark brick façade and impactful balcony, the outer appearance belies the vast size of the residence internally. After the demolition of the former mews house and after 2 years of construction, which had even necessitated underpinning the neighbouring houses, this property now accommodates a basement with indoor pool, lower ground floor with cinema room, open plan living and dining space, 2 floors of bedrooms and bathrooms, as well as additional terraced balconies.Keeping the interiors bright and airy throughout was key to the design concept – floor to ceiling windows and Flushglaze Walk On Rooflights from Glazing Vision were installed to maximise the daylight where it would have been otherwise compromised on the ground and second floors. In addition, a Glazing Vision 3 Wall Box Rooflight provides unimpeded access from an internal staircase to the impressive roof terrace, which is recessed down 1 1/2metres between 2 pitched roofs and which offers a vast outdoor space for entertaining, dining and relaxing.Two Flushglaze Walk On rooflights were specified by the architect to negate the risk of potential dark spots appearing in the dining zone and living area on the ground floor. Engineered by Glazing Vision to bespoke sizes and to meet the future projected foot traffic upon them, they were seamlessly integrated into the balconied terrace on the second floor, thus shedding light through to the bench seating in the kitchen and lounge.Their minimal internal framework was in keeping with the contemporary aesthetic of the interior, and both rooflights augment the quality and quantity of light entering this open plan area, even extending out towards the central stairwell and landing.Two further custom-sized Flushglaze Walk On Rooflights installed on the roof terrace add an intricate design detail but also create a wow factor. Perfect for flat roof terraces, these rooflights lie flush with the wooden decking. Again tested to allow for regular foot traffic and to bear the weight of terrace furniture, the rooflights offer complete safety and watertight integrity. On the second floor below, the two windowless bathrooms are flooded with the light coming through these rooflights – indeed such is the brightness of these rooms that privacy blinds have been installed for occasional use.Seeking to optimise the very large roof space that had been created (4m x 8m) the architect specified Glazing Vision’s 3 Wall Box Rooflight, which would offer easy access all year round to the roof terrace and also provide a contemporary glass feature. For the accommodation of the 3 wall mounted box rooflight a timber box frame had to be built which abutted the exposed brick wall behind.The property’s imposing central staircase provides access to the box rooflight, which in turn maximises the light falling down the stairwell to the bottom of the house. At a touch of a button from an access keypad, the sliding roof retracts to give a 50% clear opening with no “bowing of the head” necessary. The operation is quiet and safe, and the provision of a rain sensor ensures closure from inclement weather.

Thames City is a spectacular location and presence in Zone One of the River Thames. With some of the city’s most breathtaking views, especially for those not afraid of heights, this is a fresh district featuring three residential towers, a development of 12 buildings, beautiful apartments with private luxury amenities, high-end retail, and fine dining venues.The overall experience of this amazing project is made even more appealing thanks to its network of interconnecting parks, cosy green courtyards, and romantic city squares.This project was complex, involving both TerraSmart Rail Paving and TerraSmart Pedestal Paving Systems. Both these systems are designed for waterproofed substrates with TerraSmart Rail being the ultimate raised paving system, unbelievably solid thanks to its unique lattice framework.Due to the height of the tower, we worked closely with Midgard Design Services to develop and install an appropriate wind uplift mitigation solution to keep the project within budget.The TerraSmart Rail Paving System was weighted using ballast weights, and installed in the joist frame to mitigate uplift – it couldn’t be fixed into the structural slab due to it being an inverted roof. The pavers were then mechanically fixed to the joists using a wind uplift visual fixing, which clamps down the entire system.The TerraSmart Pedestal Paving System was mechanically fixed to the structural slab as there was no waterproofing membrane to penetrate underneath. The wind uplift mechanical fixing was screwed into the top of the pedestals to retain the concrete pavers and prevent any movement in strong winds.The installation of the systems was beautifully done by ANC Construction and the proof is in the photos you see on our website.

A 2,600m² high rise rooftop is transformed into a functional and attractive communal space with decking supported by Ryno RPF fixed-head adjustable decking pedestals.

When specifying the most appropriate method of waterproofing for a new-build basement it is advisable to follow the recommendations within BS 8102:2009 ‘Code of Practice for Protection of Below Ground Structures Against Water from the Ground’. The standard advises on the types of waterproofing available and confirms the performance grade to be achieved. This project required Grade 3 protection – no dampness or water penetration acceptable.

An innovative and comprehensive waterproofing solution was required to facilitate a £18m state of the art hotel and with a double story basement in Englefield Green, near Windsor. The hotel will offer exceptional overnight breaks, award-winning dining & an exclusive spa facility once completed.

Delta’s Structural Waterproofing Consultant, Paul Green, CSSW alongside Delta’s MD, Kevin Dodds, were appointed to the design team to collaborate with the Architects, Engineers, Main and Sub-Contractors to fulfil the role of Waterproofing Design Specialists in providing a reliable, watertight solution for this substantial project.The large-scale basement project consists of a 4-storey deepbasement located close to the River Thames in Central London.The proposed subterranean space would offer multiple usage. This complex project required a waterproofing design which is, able to cope with intermittent/regular hydrostatic pressures created not just by groundwater, but also geographical tidal impacts from the river Thames and potential stress challenges caused by the surrounding infrastructure such as heavily trafficked railway lines in the development’s vicinity.Structures that experience a high level of vibration fromsurrounding infrastructure can, over time, have a high propensity to suffer cracks, which could lead to failure of some waterproofing solutions, so therefore careful considerations should be incorporated into the overall waterproofing design from those aspects and, the impacts these factors can have on an elected waterproofing system.Delta’s design philosophy rotated around creating a robust and suitable waterproofing design, the structure design, a continuous system, sequencing and installation, future maintenance, and serviceability, whilst able to fulfil requirements set out in BS 8102:2022 Protection of below ground structures against water ingress. Code of practice. The British Standard which governs waterproofing of substructures.