Acoustic
bridging barrier protection
Monarfloor Acoustic Systems - Monarfloor Acoustic Bridgestop does exactly what it says on the roll
A system solution that prevents the
acoustic bridging commonly caused by mortar build-up between
separating walls, and has cleared its first hurdle in gaining
candidate RD status with Robust Details Ltd, has been launched
by Monarfloor Acoustic Systems, the Icopal subsidiary.
Monarfloor Bridgestop isolates the two skins of a cavity party
wall from mortar collecting on raft foundations and gas
membranes which typically lift the base of the cavity on
pre-cast, in-situ concrete floors as well as beam-and-block
floors.
With 70% of new build now on brownfield sites where
contamination may require raft foundations or gas barriers, the
Bridgestop system is likely to prove invaluable to house
builders, developers and structural engineers.
Icopal is confident the solution will lead to a future Robust
Detail for the block work industry towards enabling cavity
masonry separating walls to be built off rafts and continuous
slabs.
Bridgestop is laid in the cavity between the separating walls
and folded around to bridge the gap at the base.
Acoustically-resilient wall ties hold it in place with a special
cap on the first course of brickwork. A second layer can also be
used if required and held in place by new wall ties on the
second course of brickwork.
The research project behind this innovative solution has been
carried out via a joint venture between Monarfloor/Icopal and
the Building Performance Centre (BPC) at Napier University in
Edinburgh.
Dr Sean Smith, depute director at the BPC, said: “This solution
has resulted in a greater range of options for house builders
for Part E in their separating wall designs and given the block
work and concrete industry wider scope in the increasing
brownfield site market.
“At present many house builders are having to revert to 215mm
dense block solid walls but the introduction of a high acoustic
performing solution for a range of dense and lightweight block
work type cavity walls has been in the wish list of many house
builders and developers.”
The initial response from within the industry has also been very
positive. Paul Goring, principal acoustic consultant with the
NHBC, said: “Test results have been very good,” and Nigel Cox,
senior design manager at George Wimpey Central added:
“Bridgestop offers a fail save method of compiling with Part E
in modern construction.”
The Bridgestop solution also protects methane and radon barriers
from the damage that can occur when site operatives remove
mortar from the base of the walls and through Robust Detail
accreditation, would negate the need for PCT.
At present, candidate RD status has been achieved and this
recognises the performance of the new Bridgestop system. The
final hurdle, of remaining site tests to complete the candidate
RD submission, will be completed shortly.
In addition, only one coat of render instead of two is required
as well as standard plasterboard (8kg/m²) instead of 12.5kg/m²
for solid Part E solution walls, saving 4.5kg/m² of gypsum-based
board per m².
Bridgestop’s properties have high acoustic damping to absorb
more sound energy and reduce flanking, performing approximately
4-5dB better than solid walls and 2-3dB better than standard
Robust Detail E-WM-4 walls.
Email: tracy@tlcpr.co.uk