What Are Structural Insulated Panels?

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What are SIPs Panels?

When asked "What are SIPs?" our answer is straightforward... Structural Insulated Panels (or SIPs) are a high performance building system that sandwiches insulation, bonded between two boards - usually oriented strand board (OSB).

There are many forms of proprietary SIPs systems available – all of which utilise different cores and thicknesses of board, however, as the original Kingspan TEK Delivery Partner, SIPS@Clays supplies the market leading Kingspan TEK Building System.

Kingspan TEK utilises Kingspan’s high performance, fibre-free rigid thermoset Urethane Insulation for the core of the SIP panels, which is autohesively* bonded and sandwiched between two sheets of oriented strand board (OSB/3). This process is exceptionally reliable and vastly superior to the ‘secondary adhesion’ process often used in the manufacture of inferior SIPs panels.

*The chemicals that make up the core are injected between the OSB/3 boards; this creates a chemical reaction that adheres the insulation to the boards.


Kingspan TEK SIPs Panels are manufactured to the highest standards and the bespoke Building System’s use is covered by:

  • European technical Approval ETA-11/0466
  • LABC Registered Details Certificate No. EWW546
  • Kingspan’s 142mm SIP System holds BBA and NSAI Agrément certification


Starting life as 1220mm wide sheets, the SIPs panels are delivered to us in standard lengths of up to 7500mm. Following a 3D CAD design process by our in-house design team, the raw panels for each bespoke project are engineered and individually tailored at our dedicated factory in Skipton.

Kingspan TEK SIPs panels are typically used for external envelope i.e. external walls and roofs with internal loadbearing walls usually being constructed from skeleton timber frame. Using timber frame internally helps to keep costs down and allows for thinner internal walls that can house services.

Need more clarification on SIPs panels? Call (01756) 799498 today!
Exploded Sips Model White Background No Shadows

Cost-Effective, Zero Carbon Homes

What are the environmental benefits of SIPs?

Housing currently contributes to 27% of Britain’s carbon dioxide emissions. However, the insulating properties of SIPs have now made it possible to build cost-effective, zero carbon homes and buildings that are ready for the future.

SIPs are one of the most ecologically friendly building materials on the market. They can help homeowners to dramatically reduce their heating bills and significantly increase available living space in the build.

Panel Jointing System

The Kingspan TEK Building System uses a unique jointing system (Splines), which is made, in essence, from a ‘mini’ SIPs panel. It interlocks two panels whilst rigorously maintaining the insulation layer. Unlike timber frame construction, SIP panels do not rely on stud walls at 400/600mm centres in order to maintain the structure. This innovative jointing system helps to lower the overall wall U-value compared with other forms of construction such as brick and block or Insulated Concrete Formwork (ICF), minimises air leakage at connection joints and reduces thermal bridging.

Need more clarification on SIPs panels? Call (01756) 799498 today!
Spline Connection
Ossett Sips House Floor 5694 17

Intermediate Floors

Structural or intermediate floors are an integral part in any SIPs structure and to achieve the best installation results, the floors supplied by SIPS@Clays can be constructed in a couple of ways:

The first is a timber I-joist — these have a vertical web made from particle board and a top and bottom flange made of plywood. Following a simple set of guidelines they can be cut and trimmed on site and drilled as required.

The simple design characteristics of these joists means that, together with the use of the ‘hospital’ pack which is provided with the kit, small tweaks, such as remediation work to damaged joists , trimming the size of an oversized floor or changing the aperture of the staircase for example, can easily be carried out on site.

Alternatively, open web joists can be used. These have a solid top and bottom flange but with a metal vertical web. Open web joists, whilst making your electrician’s and/or plumber’s jobs a little easier (as holes don’t need to be drilled for pipes and cables) cost around 50% more than engineered I-joists. Usually this over cost in using open web joist is more than the labour cost of making the required holes in the I-joists. We suggest that you check with your electrician and plumber to see whether they will offer a reduced price based on using metal web joists.

As open web joists are unique to their length and complex in nature, they cannot be resized, cut or readily replaced on site.

Depending on the span and design criteria, both options range from 200mm to 360mm deep and will be topped with 22mm Egger Protect structural floor deck, giving rigid, squeak-free floors up to 5.5m

We would always recommend engineered I-Joists as they suit the Kingspan TEK SIPs building system and help maintain a smooth workflow on site.

Need more clarification on SIPs panels? Call (01756) 799498 today!
Etherley Farm Sips House Floor 13

"I’ve been in the industry a long time and have appreciated your honesty, support and guidance from the outset, it’s made my job as designer and client an easier one."

Andrew Wood

"I am delighted with my SIPs build project, and was highly impressed with Robert and his fitting team. They were quick, clean and efficient in their work."

Lyn Roberts

"The service your design team in particular provided, in taking our design and transferring it into your modelling and cutting system was of enormous help. The reassurance you gave us from the outset was most comforting, and indeed turned out to be absolutely well-founded.

"The whole team have been an absolute delight to deal with throughout".

Bob Dowdall

“Love the product, would definitely recommend and use again”

Tim Banks— Lancashire

“We chose SIPS@Clays because their extensive knowledge and expertise meant that we were in safe hands. The full end to end service from the design team to the SIPs build on site was professional, rigorous and well managed. We would highly recommend SIPS@Clays to anyone considering a SIPs construction.”

Graham and Gill Craven

“We want to thank you and your team for the speed and efficiency of the build. Your workforce were very impressive – they worked extremely hard (and in very wet conditions during the second week). We are delighted with the result and look forward to the next stage of the build.”

Elizabeth Fowler