Hemsec: Why SIPs are crucial to the future of the UK construction industry

This article from Hemsec explores why Structural Insulated Panels (SIPs) are crucial to the future of the UK construction industry.

Introduction

Structural Insulated Panels (SIPs) are engineered panels used to construct walls, ceilings, and floors. 

Either as a material for Modern Methods of Construction, such as offsite manufacturing, or as a replacement for traditional construction materials such as framing lumber and insulation, SIPs provide an extremely durable, strong, and energy-efficient building option.

In this document, we explain why SIPs are so relevant and crucial to building new homes and industrial and commercial premises. The benefits cover their cost-effectiveness, speed of build, safety, durability, flexibility, energy-efficiency and ability to improve overall build quality.

SIPs: the UK context

The urgent need for alternative building materials

The UK construction industry is in a state of transition.  New housing stock is needed urgently; particularly affordable homes. Successive governments have similarly failed to live up to targets pledged. The need for more commercial and industrial building is also well-publicised.

Yet the construction industry has been failing to meet these needs, due to a combination of factors. A chronic shortage of skilled labour, the unpredictability of British weather, and arguably the biggest factor – an unwillingness to change.

Now, however, the changes are beginning, and architects, developers and contractors are all considering how to adopt Modern Methods of Construction (MMC). The House of Lords Science and Technology Committee report Off-site manufacture for construction recommends a presumption in favour of MMC when granting planning permission for new developments.

Widespread use of SIPs throughout the world

MMC requires not only new methodologies, but also different materials. Whilst SIPs are not new (they were first developed in the 1950’s and 60’s), growth in their use in construction in the UK follows widespread usage and predicted growth throughout the world, and is to be welcomed for a variety of reasons.

Let us now consider the benefits of SIPs in greater detail, each of which together demonstrates the significant contribution SIPs can make in the future of UK construction.

Flexibility in Building Design 

Designed and custom-built 

Those unfamiliar with new building technologies tend to confuse SIPs buildings, with last century’s rather ugly, prefabricated constructions.  

SIPs enable the creation of buildings where design possibilities are almost endless.

Complicated shapes can be produced economically using SIPs.  Each building can be uniquely designed and custom-built to architect or designer-provided specifications.

The unique design flexibility of SIPs enables town-planners, along with their architects to create buildings to complement local styles, needs, and trends.

Precision and accuracy using CAD drafting systems

CAD drafting systems help to detail the SIP fabrication process, allowing precise cutting instructions to be sent to the SIP manufacturers (such as Hemsec) or engineers for foam, relief and spline set up.  With the help of technological design systems the architect optimise the use of materials in all areas of the building.

A key advantage of using SIPs in design is that there is no requirement for trusses in finished roof spaces.  As an example, a SIPs building provides spacious room-in-roof attic rooms which increases total floor space by up to 25% in any project.  Clearly, added floor space is desirable and adds to the value of the property.

Planning a project with Hemsec SIPs in mind, before entering into the design phase, can lead to improved efficiencies during the process and eliminate unnecessary changes during later stages.

The super-eco building benefits

The ultimate environmentally-friendly product

One of the major qualities of SIPs is that they are an environmentally-friendly resource. Their facings are made from renewable, farm-grown trees. This means that these components do not contribute to environmental degradation, making them an obvious choice for construction companies that care for the future of our planet.

Economic advantages across the project

A shell constructed from SIPs is erected much faster and, therefore, more economically than a conventional shell. They enable builders to complete their part of the building project quickly and to provide a safe, weather-protected environment for other trades to carry out their work. 

And not being weather-dependent, the project is much easier to plan and complete, which also reduces cost and uncertainty. 

Unbeatable insulation values

Insulation values for SIPs are vastly superior to conventional framing and insulating methods, as a building constructed with these panels is virtually airtight.  Occupants have excellent control over the interior environment without the problem of draughts and irregularities in air temperature.

To be precise: In a building constructed with SIPs there are none of the hot and cold spots found in homes built with conventional building materials.

As well as reducing the cost to the occupant of heating fuels, a key advantage of using SIPs in the construction of homes is that they produce far less waste than buildings constructed from conventional materials as there is a reduction in harmful gases released from burning waste as well as a reduction in the need for landfill space.  

Excellent sound resistance

As with timber studwork, acoustic performance using SIPs is determined by the mass and continuity of the plasterboard linings. Acoustic rated plasterboards are used to improve the insulation performance of walls where required.

Resistance to airborne sound: Hemsec test data indicates that separating walls, with additional plasterboard and soundproof linings will provide excellent sound resistance.

Longevity of Finished Buildings

Before a SIPs building is constructed on-site, it is important that its component parts are packaged correctly and are transported and stored safely.

Handling SIPs

During construction, the SIP structure is likely to be exposed to poor weather conditions and may become wet.  When general precautions are followed this is not an issue for SIPs. If any panels do get wet, it is important to ensure that they are allowed to dry thoroughly. Panels should not be tightly wrapped in plastic, but loosely covered to promote the movement of air and drying.

Repair and Maintenance of SIPs

As with any construction method, the long-term performance of the building will be largely dependent on repair and maintenance as necessary.

It is important to:

 – Regularly check and clean guttering and rainwater down pipes. This ensures that water runoff is collected and diverted away from the building. 
 – Flashings around the roof should be checked and repaired or replaced as required.
 – If the building is clad in render, any cracks or damage to the render should be repaired promptly.

To be expected, the external build up is likely to wear out well in advance of a main SIPs structure.

Because of the longevity and durability of SIPs, the strength of SIPs buildings are proving legendary around the globe.  They can withstand hurricanes, tornadoes and earthquakes. Provided the installation remains weather-tight and all maintenance is carried out properly, a life of at least 60 years may be expected for SIPs buildings.

Building quality

Snagging could be a thing of the past for builders and contractors who use SIPs

99% of home owners report snags and defects…. When we consider that in the 2019 Customer Satisfaction Survey by the NHBC shows that 99% of customers reported snags and defects in their home to their builders after moving in, quality is a big issue in the UK construction industry.

70% of those surveyed reported between six and fifteen problems, and more than a quarter of them (26%) reported more than 16 problems.

Straighter and flatter walls – a key benefit 

Not only are SIPs buildings faster and easier to erect than conventionally constructed buildings, but they also have straighter and flatter walls.  Industrially manufactured, SIPs are not subject to the inconsistencies of man-made construction.

This means that interior and exterior walls which are made of SIPs, are straighter and flatter than hand-built, rendered walls. This unique aspect reduces the requirement for onsite adjustments – which means little or no snagging.

Resistance to damage

Using SIPs to construct the exterior envelope of the building creates an extremely tough, durable barrier to the elements for the protection and comfort of the building’s occupants. 

SIPs buildings are capable of resisting hurricanes and tornados in storm-prone areas of the world. In Kobe, Japan in 1993, an earthquake devastated a large area of the city, but houses built with SIPs came through it virtually unscathed.

Rigorous testing and products which meet the highest levels of compliance

A technically superior product

SIPs are manufactured to the very highest standards and technically superior when compared with all other building materials. 

This statement is proven in a number of ways.

ETA and CE Mark Certification

All Hemsec SIPs have ETA accreditation and CE Mark Certification. This is a guarantee to any construction-related company in the UK and Europe that Hemsec’s products have been tested to the very highest levels.

SIPs are extensively tested for Structural, Acoustic and Thermal properties, including Fire Resistance. The results of these tests are verified by the Eurocodes. 

The CE Mark Certification process classifies SIPs as a System 1 product ensuring that during audits there is a strong focus on Factory Process Control (FPC) processes.  

Hemsec is BS EN ISO 9001:2015 certified, quantifying our quality management system and demonstrating our ability to consistently provide products and services that meet customer and regulatory requirements.

Mechanical resistance and stability

SIPs provide unbeatable strength, mechanical resistance and stability; they are strong, reliable, durable and suitable for all walls, roofs and floors in domestic, industrial and commercial construction. 

Assessing mechanical resistance and stability

Hemsec adheres to the European Technical Assessment (ETA) document, specifying precisely the rigorous tests followed as part of the Factory Production Control (FPC) process. 

SIPs panels are manufactured by sandwiching together a core of rigid closed-cell polyurethane foam (PUR) insulation bonded to the two OSB skins. This bonding makes them intrinsically strong, air and water-tight.

The six elements to verify mechanical resistance and stability are:

 1. Horizontal load capacity for walls

SIPs are composited structurally insulated panels, pre-engineered and carefully designed to withstand vertical and horizontal loads.  The load bearing ability of SIPs derives from the strong, structural bond between the three layers. 

 2. Vertical load capacity for walls (with or without eccentricity)

Under the Eurocodes our industry-leading panels generally provide a vertical loading capacity of 80kN/m. 

 3. Combined vertical/horizontal load capacity

Although SIPs are relatively light, they have the ability to bear high loads as a result of the strong structural bond between the layers.  The load supported by SIPs is conveyed to the ground by the OSB skins, with the structure held in position by the fully bonded insulation core.  SIPs can therefore bear considerable vertical and horizontal loads with reduced internal studding.

 4. Racking load capacity for 150mm thick walls:

SIPs provide a stable racking resistance for modular buildings and can reduce the overall frame of the module. In addition, by using SIPs it is possible to reduce some of the components of the frame (e.g. the amount of cross bracing) or sometimes remove the external frame of the module.

Panels demonstrate racking resistance of 13.9 kN for an example panel height of 3 metres. 

This determination of the racking strength of walls constructed using SIPs is a measure of a building system’s ability to resist wind loads

 5. Fixing capacity

SIPs are fixed with either nails or screws. Both fixes provide sufficient strength although screws are stronger and recommended

 6. Roof structural capabilities

SIPs are equally as strong and effective for use with roof systems. A SIPs 125mm panel thickness, a panel span of 3.0m and a roof slope of 60° has Panel Design Capacities of 5.04 k/N.   

Conclusion

SIPs are the ultimate solution for all types of construction projects, whether they are residential, industrial or commercial.

We are proud to be one of the UK’s largest and longest-standing insulated panel manufacturers. We work in partnership across the supply chain; trusted by companies who need absolute confidence in the timely delivery of high quality, durable building materials.

It can be an attractive solution to integrate SIPs with other materials in construction projects, whether as a load-bearing structure, for insulation, speed of construction etc. 

When we consider that SIPs are very easy to incorporate with a wide range of materials, such as CLT, it’s an important consideration when planning a project. 

Contact Hemsec

Contact Hemsec:

Stoney Lane,
Rainhill,
Merseyside
L35 9LL

T: 0151 426 7171
E: [email protected]

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