Maximising flat roof specification and installation – ADC

ADC on November 1, 2022

Rob Edwards, Trading Director at SIG Design and Technology, discusses the company’s core service principles and how these can benefit specifiers, with Architecture Today’s Technical Editor John Ramshaw.

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While flat roofs have long been admired for their aesthetics, efficiency, and material economy, they remain technically challenging – not least in ensuring a long service life with excellent levels of weather performance. For architects, flat roof specification can be a bewildering experience with countless products – both specialist and non-specialist – to choose from, as well as extensive design, regulatory, and installation criteria to fulfil.

Fortunately help is at hand from one of the UK’s largest and most respected designers and suppliers of high-quality flat roofing solutions: SIG Design and Technology. Central to the company’s success are three core principles: product agnosticism, technical expertise, and installation excellence via the SIG Design and Technology Accredited Contractor scheme (DATAC). Rob Edwards, Trading Director at SIG Design and Technology, in conversation with Architecture Today’s Technical Editor John Ramshaw, discusses these key elements and how they benefit specifiers.

What kinds of flat roofing solution does SIG provide?

SIG D&T designs and supplies a wide range of flat roofs, comprising single ply membranes by IKO and FDT; liquid solutions, including Hydrostop AH+ and SIGnature Ultra Protect; EPDM roofing; bituminous membranes, such as the SIGnature Torch-on System; hot melt and mastic asphalt systems by IKO, as well as green and blue roofs from Eco Green Roofs. We also design and supply slate and metals roofs via out sister companies SIG Roofing Natural Slate and  SIG Zinc & Copper respectively. With such a wide choice of materials available to us, we can help specifiers make the right choices in terms of design criteria, performance in use, and of course cost.


SIG’s product agnostic approach means that it will always recommend the best roofing solution(s) for any project (ph: Adam Coupe)

What is meant by ‘product agnosticism’ and why is this important to SIG and its customer offering?

Being product agnostic allows us to be impartial during the design process. We don’t approach projects with a single product in mind, which we then try to make fit the application. Instead, we are able to choose from a wide range of solutions and can therefore advise on the right product for the particular application and client brief. We’re more flexible and, unlike some companies, can supply what is needed, rather than the ‘nearest fit’ from a limited selection of products. This also allows us to expertly mix and match different products to cope with specific design and detail requirements, while also keeping costs down.

SIG is currently working towards CCPI (Code for Construction Product Information)  compliance, which will provide added assurance that architects and facilities managers have all the necessary facts when making decisions about specifying or installing our products. It’s about transparency and ensuring specifiers have a clear idea of the product’s performance and a better understanding of what the specification involves.


Roofing contractors must apply to become DATAC members and undertake training before being supplied with SIG’s roofing products

What kind of technical expertise is available to specifiers with regards to product selection and detailing, and how does SIG facilitate this?SIG can undertake full NBS specifications for both new-build and refurbishment projects. We offer calculations for U-values, wind uplift and drainage, together with an inhouse design team that can produce bespoke detailing for projects if required. At the moment we have around 20 specification managers located around the country, who are all experts in flat roofing. Each one understands their particular region in respect of the market, and has a close relationship with the local installers.

The specification managers are able to liaise with and advise architects from earliest point in the design process – which is always preferable – on new-build projects. For refurbishment schemes, they can carry out intrusive on-site inspections to determine the condition of the roof and  see if there is water ingress in the existing waterproofing, or conduct a wider survey to ascertain the best way forward for the roofing element of the project.


DATAC training session

What is DATAC and why is this important for specifiers?

Established in 2009, DATAC is our accredited contractors scheme, which ensures that specifiers, clients and main contractors deal with financially credible, well trained specialist roofing contractors, who have an on-going relationship with the products they work with and are supported on site to deliver high-quality projects.

How does the DATAC training process work?

Essentially, roofing contractors have to apply to become DATAC members and are then trained before being supplied with our roofing products. This denotes ‘blue status’. Following this, they enter a process of on-going support, training and evaluation to ensure their work is of a consistently high standard, after which they may be upgraded to the ‘green status’. This is beneficial to all parties: the contractor develops and maintain skills and gets accredited quicker, specifiers can rely on their expertise, and clients and end users know that their roof has been installed by a committed, competent team.


DATAC installers sign a deed of indemnity on their workmanship, which means that they have to correct any future problems related to this aspect of their work on SIG projects

Is DATAC linked to the roofing warranties that SIG is able to provide? And if so what are the typical warranty periods for the different roof types you supply?

SIG will provide a project warranty where we know that the roofing contractor has been trained on the installation process. DATAC installers sign a deed of indemnity on their workmanship, which means that they have to correct any future problems related to this aspect of their work on SIG projects. We carry out credit checks on DATAC installers every year and ensure that they have insurance cover of £1m (minimum) for public and product liability, and £5m (minimum) for employer’s liability.

Depending on the product, warranties can range from 15-25 years, but this is normally discussed during the client briefing process. The idea is for specifiers to really engage with us as early as possible, so we can understand the employer’s requirements, the stakeholder’s brief, and all the other factors influencing the design. Ultimately, it’s about the right choice of product, installed in the right manner, that meets the client brief, whilst also being conscious of cost, legislation and best practice.

What additional site support services does SIG provide in terms of monitoring and quality assurance?

During installation, SIG provide site support for all our approved contractors and projects. Further services include ‘tool box talks’, which provide initial site support, and health and safety briefings.

Contact Details

For more information, please visit the SIG Design and Technology website.

Source: Architecture Today