ROCKWOOL launches new flat roof insulation solution

15 April 2019

ROCKWOOL has answered the need for a thermally efficient, non-combustible flat roof insulation by launching a new product, HARDROCK® (DD) TRB.

HARDROCK (DD) TRB  - Flat Roof Thermal Application

HARDROCK® (DD) TRB (Thermal Roof Board) is a rigid dual-density stone wool insulation which is purpose-designed to give an enhanced thermal performance across roofs that are subject to maintenance-only foot traffic. Manufactured using ROCKWOOL’s patented dual density technology, this A1 non-combustible thermal roof insulation board is ideal for large flat roof areas typically found on storage, logistics and distribution centres, as well as for education, healthcare and residential roofing applications.


"The roof is often overlooked in terms of fire safety, particularly from a regulatory standpoint - which can result in specifiers inadvertently yet routinely introducing a weak link into the building envelope via the unconsidered ‘fifth façade’", comments Will Wigfield, Product Manager at ROCKWOOL. “However, there now exists a non-combustible flat roof insulation capable of meeting stringent thermal requirements in just one layer – offering contractors a quick and easy install without compromising fire safety. HARDROCK® (DD) TRB achieves the highest-attainable Euroclass A1 rating under EN 13501-1 meaning that it simply will not burn.”


HARDROCK® (DD) TRB is easy to handle on site, and in the majority of applications can be securely installed within a mechanically-fixed single-ply waterproofing system using just one fixing per board*, in contrast to the multiple fixings needed with PIR foam board installation.  The result is a quick and simple installation, reducing any risks of cold bridging that may otherwise compromise thermal performance.

With a length of 2000mm and a width of 600mm, HARDROCK® (DD) TRB is supplied in a choice of four thicknesses – 145mm, 175mm, 190mm and 230mm – catering for commonly requested U-values ranging from 0.25 W/m²K to 0.15 W/m²K in a single layer.

Manufactured from basalt rock, which is melted, spun and bound to create stone wool insulation boards, HARDROCK® (DD) TRB is dimensionally stable, eliminating the need for any mechanical fasteners to prevent differential thermal expansion and undue stress on the waterproofing membrane. It is also water repellent and completely unaffected by damage caused by the freeze/thaw cycle.

HARDROCK® (DD) TRB Thermal Roof Board is available as a specification-only product, supported by ROCKWOOL’s Technical Solutions team who can provide U-value calculations, BIM modelling, and detailed technical guidance for all projects.


*Editor’s note: Exceptions may occur that demand multiple fixings. For example, the corner regions of flat roof systems will be subject to increased external suction and internal pressure force, meaning it is important to increase the number of fixings per square metre and to reduce the distance between the rows of fasteners.