Category Archives: Roofing Blogs

Built-Up V Composite Panels – Which do you favour?

Lorraine Koertzen is Category Manager for the SIG Industrial Roofing Centre (IRC) and has been working for this specialist division of SIG for over 10 years.

Based in Manchester, but supporting Industrial Roofing Contractors across the UK, the team at SIG IRC provide impartial advice to help roofers design roofing systems that comply to all building regulations. They offer a pretty unique national service and the team know a lot about Industrial Roofing, so we asked Lorraine “what’s topical in the industrial roofing world right now” and she confirmed the dilema of whether to use a Built-Up or Composite Panel system is now a daily debate they are having with roofing contractors. 

Here are her thoughts on the issue…

Built-up or Composite?

Traditionally, any industrial roof that required insulation would be created by what is now refered to as a ‘Built-Up’ system. Here a liner, bar and bracket, insulation and top metal sheeting would all be laid down separately to create the roof, with individual fixings required for each layer. Overall it did, and still does, offer a customised solution, although it can be a time consuming process where labour costs are invariably high.

Then composite panels were introduced to the market, modular systems that offered the contractor factory bonded panels comprising two metal sheets bonded usually with PIR insulation (polyisocyanurate). They came in different sizes, shapes and colours and became recognised as a product that whilst more expensive to buy, were easier and quicker to fit. It was simply a case of knowing the thickness of panel required, as well as the profile and colour of the top sheet required.  

The trajectory of sales for these new composite panels started to overtake all other types of metal roof coverings. It saved roofers time and money and as no special skillsets were required to install these panels, with the skills shortage growing, the panels offered huge benefits for many roofing contractors. Being available for both Roof and Wall applications too, also meant that the full building could be covered in record time.

What’s changed?

Over the past year we’ve seen a growing number of contractors question which is the best system to use on their projects. So, what has changed in the market to create this debate?

Firstly, the investigations, reports and subsequent building regulation changes as a result of the Grenfell disaster have had a huge impact on the market. Not that is was directly relevant to roofing, but expanded foam is present in many composite panels and in some projects contractors are now seeking higher ‘integrity’, non-combustible options like mineral wool which are not readily available in panels.

The qualities of a panel are measure in ‘Integrity’ which is the length of time it takes for the panel to show damage from fire and is usually measured in minutes (30,60,90,120 & 240 minutes) in theory the length of time you have to exit a building that is on fire. Plus ‘U-Values’  which is the rate at which heat is transferred through the panel, the better the resistance the lower the U Value (U is the symbol for Internal Energy).

The growing green movement is also having an effect as there are some composite panels which are recyclable or contain some recycled materials and use different chemicals within the insulation to improve the fire resistance of the product, but very few panels can meet the most stringent insulation and non combustible requirements. Any that come close  are usually very heavy to lift and that in itself can cause problems with off loading and labour resources on site. On many refurbishment projects the weight of the product alone can eliminate it from consideration for the building project.

The drive for solar panels to be fitted to industrial roofs is also a new sustainable consideration. Can the building sustain the additional weight? And currently only one supplier of metal sheeting  has confirmed that their warranties will cover the coating if solar panels are fitted. Coating warranty implications should be considered if any Solar project is being retrofitted to an Industrial roof.

The bespoke benefits of a built-up system allow for different top sheet coatings and types of insulation to be used and the weight of the individual components are lighter to move around on site. So whilst it may be a more lengthy process to install, it can offer peace of mind to the end user who is usually the standard setter.

Finally, there was also some confusion created when the BRE removed the LPCB certification from Kingspan products, Although full insurance backed cover from FM Global giant was never in question and the BRE quickly reinstated the LPCB status on all Kingspan products, for some contractors it raised a question on all types of PIR insulated panels.

So there has been a collection of recent changes and conversations in the market that have resulted in the roofing contractor having to decide what is the best product to use for a particular project and the best system, be it Built-Up or Composite Panels.

How can SIG IRC help?

At SIG IRC our job is to help our customers to consider the options, once we understand the requirements of the roof and building. We need to understand what they are trying to achieve with a particular project and we then go through a check list to discount or add certain possibilities. 

There are so many different elements to consider with either a new or refurbished industrial roof. Does the building need insulation and to what level? What is the building being used for or converted to? What substructures are currently in place? Is air leakage or noise reduction a consideration? If an over-roofing project is being considered, does the incumbent roof contain asbestos? What weight considerations need to be looked at? is it possible to over roof? Will solar installations be a requirement?

At SIG IRC we deal with all manufacturing suppliers of Industrial Roofing products so we can offer our contractor customers totally unbiased advice on what product options they have.

As a distributor we have no preference as to what products a contractor wishes to use for a project we just want to help get the right product at the right price for the right project, right first time.

If a customer requires it we can can provide two options and outline the benefits of each to help the contractor be better informed to make the choice.

Sometimes on projects without Architectural input the decision comes down to personal preference of the contractor as some contractors still prefer Built-Up over Composite installations. Other times it will come down to which offers the best performance or price for that job.

Our People – Duncan Winter

The employees of SIG Roofing are key to its success, whether customer-facing or working behind the scenes. SIG believe strongly in investing in the right people, with the knowledge, experience and qualifications in the market it serves.

So, in a series of articles we want to introduce them to you, to showcase their value and the part that they play. First up is our Commercial Director…..DUNCAN WINTER.

Duncan Winter was made Commercial Director for SIG Roofing and Exteriors in November last year.  He may be relatively new to the role, but he certainly isn’t new to the roofing market having started life ‘on the tools’ as a roofer 18 years ago.


Duncan Winter came from a farming family in Lincolnshire and moved into a career in roofing quite by chance.

After a number of years ‘on the tools’ he took up a role in contractor training with a company called Flex-R where he developed through various roles until it was sold to SIG in 2015. By this time Duncan had enjoyed time both training and selling for the business and ended up as General Manager at the time of the acquisition.

Duncan looks back fondly to those training days, especially when he worked on-site with contractors demonstrating Flex-R products and how to do larger roof spaces. He remembers roofers, in the early days of their trade, that wouldn’t do a roof larger than a dormer that now won’t do a roof smaller than 1000 sq ft., and he still remains in touch with a number of those contractors today.

The Flex-R business, which specialises in flat roofs, grew year on year and the SIG acquisition was a bonus to that growth.

Flex-R has always traded as an independent business, albeit part of the SIG Group, and for the next two years after the acquisition, Duncan continued to work as its General Manager.  It was a great fit with the SIG Group, Flex-R have exclusive UK distribution rights for their products from their US supply partner, and these products are still very much in demand, despite a generally decreasing market in flat roof installations.

By 2017 Duncan’s role had grown to include the management of the SIG Design & Technology division and this was followed by responsibility for SR Timber and SIG Industrial Roofing, both specialist areas that, according to Duncan, required support more than management.

Duncan’s role was changed again in 2020 with a focus on the SIG Specialist businesses, like high-temperature insulation and glazing, which helped further broaden his general business knowledge. All the experience he has gathered, he believes will help him in the challenging role he faces as Commercial Director for the SIG UK Roofing & Exteriors Division.

What is the Commercial Teams challenge today?

SIG Roofing & Exteriors has a UK turnover of C£400million and they are more than double the size in turnover of their nearest competitor. They have 105 roofing branches spread and servicing the whole of the UK and these branches truly support their local customers, stocking products that are in demand locally so they can be delivered to site at speed.

So, as the Commercial Director for the Roofing Division, how can he improve that performance?

“I will continue to support the Flex-R, SRTimber and Industrial Roofing businesses, but my day-to-day role and focus is on SIG Roofing and that is all about continual improvement.”


New products have to be proven to be successful in this market, rightly so when any failure comes at such a high cost. So the focus for the commercial category team is to think longer term and work closely with our supply partners, to build strong relationships, with a goal to be the first to market with new product innovations.


The commercial team can constantly improve efficiencies by working more closely with the SIG Roofing MD’s for the North and South. Here the goal is to balance a strategy of acting as a National business with strong buying credentials, which in turn benefit the local market.


A large business can overcomplicate its offer and we want to keep it simple. There are four key areas of the SIG roofing business, Insulation, Roofline, Flat Roofing and Solar, and the commercial team need to help the branches sell the whole basket. An average pitched roof lasts 50 years and a flat roof 20 years, so we have very few chances to sell all the products for that roof for that one sale. Our target is to support our branches to improve their ratio of supporting our customers with all that we have to offer.


Growing our support by investing back into the industry. Encouraging people to come into the roofing industry as a career choice.  It is a valuable skill, a trade, and SIG wants to support that. SIG are members of the NFRC (National Federation of Roofing Contractors) and the commercial team attend relevant meetings where we will be actively increasing our support with projects that benefit the future of the industry…..

“Once in the roofing industry, people rarely leave and I’ve met some great characters. I’m really pleased that I started ‘on the tools’, those early lessons I learnt have been very helpful throughout my career.”

Flat roof refurbishment: David Gray Case Study

Industrial units and commercial roofs require regular maintenance and over time will eventually require refurbishment.  When the client found they needed to conduct major repair works on their factory roof, D Gray Services partnered with SIG Industrial Roofing to develop a project plan to bring the roof back to condition within timescale and budget.

Roof repair products

The project goals were to provide the client with a full refurbishment of both the flat roof and the industrial roof. SIG Industrial Roofing and D Gray Services worked together to identify products that were best suited to the project which would have the durability that the client needed.

They supplied SIG FIX-R classic underlay along with SIGnature charcoal cap sheet. This led to D Gray Services having multiple drops including Ash and Lacy bar and bracket system, along with fixings to help over-clad the existing worn-down roof sheets. SIG Distribution then provided 140mm Knauf cladding roll to help re-insulate the building and Joris Ide supplied the metal roof sheets and metal flashings and fabrications.

Roofing contractor and supplier collaboration

An important element of the repair involved the close teamwork between D Gray Services, SIG IRC, and key suppliers such as Knauf or Joris Ide.  This is typical of SIG Industrial Roofing Centre’s approach to projects thanks to their 9-step framework. This easy, comprehensive process is implemented to transform roofs.

The holistic approach employed by SIG Industrial Roofing encouraged multiple suppliers to come together to make the project a success. With their ‘working together’ attitude, the project was completed swiftly and efficiently.

“It’s good to be recommended a C200 Plastisol coating on roof sheets, that way I can offer the customer a 25-year warranty on the corrosion of the sheet”

Dave from D Gray Services

For more information on how SIG Industrial roofing can help with your project, please call us on 0330 123 1850. Alternatively, email us by clicking below or visit our website.



Helping to build a brighter Hull

SIG Roofing has been at the centre, or more accurately the top, of many of the most impressive regeneration projects currently underway in Hull

Gone are the days when Hull was considered one of Britain’s least attractive towns to live in.

Over the last 20 years, the city has enjoyed a host of redevelopment projects aimed at rejuvenating the centre and upgrading the city’s infrastructure.

The title of City of Culture in 2017 accelerated this drive, with the Council committing £100 million for regeneration projects to spruce up the city in the lead up to 2017 and beyond.

But the redevelopment hasn’t stopped there. The last 12 months have seen a number of exciting projects across the city. Hull’s famous and imposing Guildhall is currently in the middle of an overhaul of its historic roof, with replacement slates set to give its already impressive countenance a welcome facelift.

The first phase of the project, which went to the drawing board in 2019 but has suffered delays due to Covid-19 and the accompanying restrictions, involved the use of 40 tonnes of slate to replace the existing roof tiles. The Burlington stone slate used on the landmark Grade II building was supplied by specialist roofing supplier SIG Roofing and comes from across the Pennines in the Lake District.

The prestigious slate gets its unique appearance due to the geological processes spanning millions of years that went into forming the hills it was mined from.

From the historic to the contemporary, Hull’s up-and-coming Fruit Market district is also involved in a top and tails make-over. The impressive redevelopment has seen the old fruit market around Humber Street transformed from a run-down warehouse district by the docks into a contemporary space occupied by cafes, restaurants, bars, artists’ studios and boutique shops. Included in the £80m transformation of the Fruit Market is the upgrading, or outright replacement, of many of its roofs with SIGA slate, also supplied by SIG Roofing.

In fact, SIG Roofing is a theme that runs through a number of the redevelopment projects going on in Hull today. Operating out of its branch in Anchor Trade Park on Wiltshire Road, the business and its staff have played witness to many of the recent changes Hull has been through.

SIG Roofing Assistant Branch Manager Alex Britton is Hull born and bred. He recalls what the Fruit Market was like before the redevelopment began:

“I remember the old fruit market. It used to be full of boarded up warehouses – not that they were too scruffy, but they were big padlocked buildings which hadn’t been attended to, with paint flaking off and maybe a few broken windows from teenagers being teenagers. That’s really how I remember it.”

This is a far cry from the feel of today’s Fruit Market. Considered a prime Friday night target in the times when we were able to go out, the Market has also transformed into an idyllic daytime destination to sit and catch up over coffee.

“For the past maybe five or six years this has been the place to be, just because of the redevelopment,” Alex said.

“I can’t see that changing any time soon because it’s such a nice place, you’ve got nice scenery, what they’ve got to offer in bars and restaurant is brilliant and when you’re sat outside, you’re looking on to the marina. I’ve never been bored of looking out at the sunset on the marina, it’s just relaxing with a great atmosphere.”

Moving away from the city centre, SIG Roofing has played a major part in several other major projects in Hull. For the last four years, the branch has been supplying roofing materials for the huge housing development around the East Hull area. The Ings Road regeneration is a multi-phase project providing over 700 new homes to the area. Using Sandtoft’s Calderdale Edge, a flat concrete tile with a slate-like appearance, the first phase of the project was completed in 2016. The latest phase is now fully underway and will be ongoing throughout 2021.

Over on the North side of the city, SIG Roofing is midway through supplying a large refurbishment scheme on the Bransholme estate. Once described as Europe’s largest housing estate, the 492 properties at Bransholme will also be re-roofed using Sandtoft Calderdales, with the project expected to be completed this year.

From historic buildings such as the Guildhall to fashionable and modern areas like The Fruit Market, as well as vital housing projects such as those of Ings Road and Bransholme, SIG Roofing has proudly played its part in rejuvenating the centuries-old port city, helping to maintain its place as the vibrant centre of the Humber region.

New regulator: a step forward in compliance and safety

In January the government announced the introduction of a national construction materials regulator. Here, Andy Williamson, Commercial Director – UK, for SIG Plc, welcomes the move and discusses the importance of using roofing products that are safe and compliant.

The construction industry is hugely important to all our lives. It is a key driver for the economy, a significant source of employment and, of course, a provider of homes, schools, workplaces, hospitals and leisure spaces.

Rightly, it is subject to a raft of regulations covering, among other things, materials, working methods and practices, and safety.

The roofing sector, as an important part of this industry, has a major role to play. Any measures that help maintain and, where appropriate, drive up standards are hugely welcomed. The appointment of a national Construction Products Regulator can only be a step forward.

The new regulator, set up with a £10 million fund, will be based within the Office for Product Safety and Standards (OPSS) and work with Trading Standards to ‘encourage and enforce’ compliance where it is needed.

Not only will it be able to order the removal of any product that presents a significant safety risk, it will also have the authority to prosecute companies that flout the rules on product safety.

In addition, it will have strong enforcement powers and the ability to conduct its own testing when carrying out investigations.

Well-run roofing companies, and the wider construction industry, should not be wary of this.
Instead, the regulator should be supported and seen as an opportunity to reset and build back any confidence in building safety which may have been lost, while further reinforcing the industry’s determination to prevent unproven products entering the market.

The vast majority of tradespeople go to great lengths to ensure the working practices they implement, and the materials they use, are safe, compliant and fit-for-purpose.

Hopefully, the new regulator, with the support of us all, will be able to root out and put a stop to the types of poor-quality materials and practices that have led to the establishment of this new OPSS division.

In addition to the new regulator, the government has commissioned an independent review to look for weaknesses in product testing regimes. We look forward to reviewing its recommendations, which will be delivered later this year.

As a major distributor of specialist building materials, SIG has always had a strong focus on product quality and ensuring that what we offer meets, if not exceeds, the relevant standards.
We achieve this by:

  • Taking the time to build strong relationships with market leading manufacturers where we know their products have been properly tried, tested and approved
  • Making sure all stock items have been considered against the appropriate regulatory requirements, such as REACH, covering chemicals content, RoHS (Restriction of Hazardous Substances), Product Safety & Handling, Declaration of Performance, Safety Data Sheets, and many more
  • Ensuring all documentation provided by suppliers is validated for legal compliance, and not just taken as read

Our well-established compliance tracking system, SIG Assured, also keeps pace with changing legislation and product development, consistently monitoring which companies and products are compliant.

This comprehensive approach to compliance means that roofing contractors can be confident the materials they have bought meet the legal requirements and their provenance is fully traceable.

We are also a member of the national Construction Products Association (CPA), which champions quality products and provides us with an additional route to track changes in regulation and government policy.

The CPA also provides the opportunity for industry to offer advice to policy-makers on issues such as decarbonisation and greener construction methods.

There are, of course, a number of excellent roofing industry-led initiatives already in place, where the focus is on increasing skills and operating in a professional manner.

Not least is the National Federation of Roofing Contractors’ (NFRC’) Competent Person Scheme which allows roofing contractors to self-certify that the work done meets the requirements of Approved Document L1B of the Building Regulations, with a 10-year insurance backed guarantee.

There is also good work being done in setting and maintaining standards by CoRC (Confederation of Roofing Contractors).

Systems that highlight the standards to which construction products are held are of vital importance to the industry, not only to ensure the very highest safety considerations are in place both during a project and after its completion, but also to reassure the public and guarantee their continued confidence in the construction sector.

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