ProTherm G XPS X 500 SL


ProTherm G XPS X 500 SL inverted roof insulation is a rigid, closed cell type Extruded polystyrene board with integral high density skin. ProTherm G XPS X 500 SL inverted roof insulation has a Zero Ozone Depletion Potential (ODP), a Global Warming Potential (GWP) of less than 5 and an A rating in accordance with the Green Guide to Specification. For use with Inverted Roof Waterproofing such as PermaQuik PQ 6100, EshaFlex, EshaUniversal, ParaFlex FD and ReadySeal.

For a comprehensive NBS J31 specification contact Radmat Building Products.

ProTherm G XPS X 500 SL is suitable for use in roofs, roof terraces, enclosed balconies over heated space and insulated walkways in an inverted roof construction. When used in the inverted roof constructions listed in the Fire Performance section below roof constructions incorporating ProTherm G XPS X 500 SL achieve Broof(t4) Classification to BS EN 13501-5 as required by Approved Document B 2019 edition, Section B4, Limitations on roof coverings.

ProTherm G XPS X 500 SL is not suitable for use in inverted roof applications on specified attachments such as projecting open balconies, projecting enclosed balconies, recessed open balconies or recessed enclosed balconies.

ProTherm G XPS X 500 SL is not suitable for use in warm roof applications (where the waterproofing is installed above the insulation board).

ISO 9001@2008 Quality Management System, ISO 14001 :200 Environmental Management System, EPD as per ISO 14025 and EN 15804.

The product, in conjunction with the specified ballast layer, can accept limited foot traffic associated with maintenance operations.

The product will have a life of at least 25 years under normal circumstances.

As a roofing system for roofs, roof terraces, enclosed balconies over heated space and insulated walkways
In accordance with Annex of Commission Decision 2000/553/EC, when used in an inverted roof specification including an inorganic covering of either loose laid gravel with a thickness of at least 50mm or a mass ≥ 80 kg/m², sand/cement screed to a thickness of at least 30mm, or cast stone or mineral slabs of at least 40mm thickness a roof system incorporating ProTherm G XPS X 500 SL can be considered to be unrestricted under the national Requirements (Classification Broof(t4) to BS EN 13501-5:2016).

Hexabromocyclododecane (HBCD) was phased out prior to the 21st August 2015.


Radmat_Green-Blue roof

Green & Blue

Green & Blue: joined up thinking to reduce flood risk

Radmat_Green-Blue roof

Back in 2000 the roofing industry got behind the emerging demand for green roofing, which was being significantly lead by the London Borough Planning Offices, the Mayor’s ‘London Plan’ and organisations such as

Whilst there are many positive drivers behind the reasons for using green roofs the main drivers could be seen as incident rainfall control, air pollution and biodiversity. Fast forward through the evolution of Green Roofs, and so called ‘Brown’ Roofs (un-planted roofs left to nature), the roofing industry are now investing in the development of Blue Roofs.

Blue Roofs are a method of providing a Sustainable Drainage System (Suds) at roof level. They provide attenuation of rainfall at a far higher level than the Green Roof that is typically installed over the Blue Roof.

Consisting of a water storage medium, typically a cellular geocomposite drainage/retention board, and a discharge control mechanism, Blue roofs attenuate rainwater rather than drain it as quickly as possible. Correctly designing the Blue Roof releases attenuated water at the required discharge rate of site, providing the integral source control and attenuation required by a SuDS system without the requirement for land consuming ponds and retention basins or below ground geocellular storage tanks. Blue Roofs can also be used in conjunction with these more traditional water control methods.

Incorporated in an inverted roof construction the Blue Roof elements are installed above the insulation and thermal sheet, and can be finished with a green roof (extensive, wildflower, biodiverse or intensive), paving or gravel ballast. Waterproofing materials such as Radmat’s PermaQuik PQ6100 Hot Melt Monolithic Waterproofing are BBA Certified for zero falls applications with a durability for the lifetime of the building, and are ideal for Blue Roof applications where security against water ingress is a priority.


Jonathan Ward, an associate director at Arup simply describes a Blue Roof as ‘a flat roof allows stormwater to be temporarily stored and drain away slowly over a few hours, thereby reducing flood risks.’  What’s more the roof area doesn’t have to be significant; a roof of less than 300m2 can attenuate 94% of the rainfall volume of a 1 in 100 year 6 hour storm event, draining over a 27 hour period.

Blue Roofs are not a new idea. They have been around in one form or another for well over 60 years, in the UK, Europe and the USA. They can be used for attenuation, storage, grey water harvesting or a combination thereof. They can go even further, like the University of Toronto’s Innovation Complex, which has a zero-runoff roof that incorporates a green roof, wind turbines and solar PV.

So why aren’t we building more blue roofs in the UK? The answer to that probably lies in scepticism, outdated concerns over flat roofing materials and a lack of guidance documents and legislation.

To breach these boundaries a pan industry working group has been established by the National Federation of Roofing Contractors Joint Flat Roofing Technical Committee. Consisting of the NHBC, BBA and representative of a number of waterproofing trade bodies, waterproofing manufacturers and drainage manufacturers the committee intends to tackle the issues of certification and Codes of Best Practice.  With these instruments in hand the committee will move on to pressing government and the EA to look more closely at the positive contributions to flood risk management that Blue roofs can have, to both New Construction and existing buildings.

If you would like more information about any of the products and systems mentioned, please contact

 Article as published in Specification Magazine Feb 17