September 27, 2021

New ROCKWOOL® solution simplifies rainscreen fire stopping

Responding to the market’s need for simplified specification of fire stopping solutions in rainscreen systems, ROCKWOOL has streamlined its range of open state cavity barriers (SP Firestop OSCB) to provide a two-hour performance rating for both 25mm and 44mm open cavities. 

Designed for use in conjunction with ROCKWOOL RAINSCREEN DUO SLAB®*, SP Firestop OSCB is fully tested to ASFP TGD-19 and is proven to provide up to 120 minutes fire integrity and insulation.

“Fire stopping is essential in rainscreen systems to prevent the spread of smoke and flames through the cavity in the event of a fire, where there is a risk of it bypassing compartmentation lines,” comments Will Wigfield, Product Manager – Building Envelope, ROCKWOOL UK. “Tested to provide up to 120 minutes fire stopping across the range, SP Firestop OSCB gives specifiers confidence that it will deliver the protection required.

“This is especially relevant in light of the ongoing conversation around fire safety in high rise buildings over 18 metres. The new format ROCKWOOL SP Firestop OSCB makes it easier for specifiers to support the construction of safe façade systems, and we’re also confident that reducing the range down to two essential products makes selection of the correct product easier.”

ROCKWOOL SP Firestop OSCB is now available for cavity widths up to 600mm, inclusive of a 25mm open air space (OSCB 25), or cavities up to 425mm with a 44mm air space (OSCB 44). The variants are easily identifiable by their respective white and red weatherproof polythene wraps. SP Firestop OSCB is constructed of an intumescent strip fixed to non-combustible stone wool insulation. When exposed to fire, the intumescent strip rapidly expands to prevent the passage of smoke and flames through the rainscreen cavity.

To learn more about SP Firestop OSCB, and further non-combustible insulation solutions for ventilated façades, visit the ROCKWOOL Ventilated Façade Resource Hub: www.rockwool.com/uk/ventilated-facade-hub


*SP Firestop OSCB is only compatible for use in conjunction with ROCKWOOL RAINSCREEN DUO SLAB®

**ASFP Technical Guidance Document 19: Fire resistance Test for ‘open-state’ cavity barriers used in the external envelope or fabric of buildings