Project Overview

Polystyrene structural inserts for a ring beam, ridge and conservatory roof sections are becoming increasingly specified for new conservatory roof designs, conversions and replacements. The EPS inserts act as a thermal barrier to prevent cold bridging within the voids of the roof sections.

Over recent years regulations for thermal insulation have tightened, for both domestic and commercial properties (you can read more about this here). For domestic properties, conservatories are the least thermally efficient areas of a home, made up of predominately glass windows and doors.  There has been a rise in conservatory roof replacements to improve the overall thermal efficiency and improve the functionality of the rooms. With solid roof replacements, manufacturers are now insulating the structural frames to improve the prevention of cold bridging within their structures.

polystyrene structural insert
polystyrene window inserts


  • Polystyrene is a low thermal conductor and will prevent heat loss through roof sections.
  • EPS inserts are easy to install, requiring no specialist tooling or equipment
  • Made from 98% air, EPS has fantastic insulative qualities
  • Molygran can precisely cut to exacting standards and complex designs
  • Molygran offer a full service, from design to delivery
  • Molygran have extremely quick turnaround times

The brief The brief

Building Regulations are minimum standards set to achieve the required thermal insulation for all design, construction and alterations to buildings throughout England, Scotland and Wales. Over recent years these regulations have tightened which has lead to all domestic new builds having a much lower recommended U-Value. With this, the prevention of cold bridging has taken on greater significance, leading manufacturers to look into their processes to improve the thermal efficiency of their structures.
With the rise in the replacement of conservatory rooves, manufacturers are now beginning to insulate their roof structures. Polystyrene inserts are being used as thermal barriers to fill the voids within ring beams, ridges and other roof sections.

The solution The solution

Manufactured from only the highest quality expanded polystyrene, Molygran’s profile cut insulation inserts are custom made to fit any roof section required.
Expanded polystyrene offers the best cost-performance ratio of any insulation type. With U-Values as low as 0.030W/mk, EPS inserts have become one of the preferred methods to improve the thermal efficiency of roof structures.
Using our state of the art technology, we are able to produce the most intricate and complicated shapes to fit into the roof sections. Made from 98% air, even large profiles are extremely lightweight and can be handled by one person. They require no specialist equipment for installation as they are cut snuggly to fit into the section.