6.0 Structural
integrity
Poplar Baths has heen the subject of a number of
surveys which have sought to establish the structural
integrity of the building. However, the surveys present
somewhat diverging views on the condition of the
building. A summary of these findings are detailed
below and copies ot the structural surveys can be made
available on request.
In 1988 consulting engineers Alan Baxter & Associates
(ABA), were commissioned to prepare an engineering
appraisal of the building. The study notes that the
building is constructed of steel largely cased in
concrete and grey bricks. However, the original
designer did not adequately protect the steel from
moisture. The steel is unpainted in many places and at
points comes within 3 inches of the face of the
brickwork. Some of the steel beams have been cast in
concrete but the cover has also proved too shallow.
The ABA report notes that these design faults, which
are present throughout the building, have led to
moisture penetration and corrosion, which was
exacerbated by the chlorine present in the
atmosphere. The consequent expansive forces have
cracked the brickwork and masonry allowing direct
penetration of water and thereby accelerating the
corrosion process and the damage is most severe on
the north side of the building. It is noted that this
process of degradation is likely to have begun within a
decade of the building's completion.
The ABA report notes that most of the steel members
were showing signs of cracking, particularly on the
damp north elevation. Repairs then underway were
judged to be well executed, involving the cleaning and
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painting of steelwork, but it was considered that the
structural problems are inherent in the design and only
very extensive intervention, amounting to a near total
rebuilding, could save the structure for the longer term.
In October 2000, the baths were spotlisted and the
English Heritage Inspector's Advice report to the
Secretary of State drew attention to the issue of the
structural soundness of the building. The Inspector
states that the concrete frame of the interior is entirely
sound and had not deteriorated since the previous
inspection twelve years earlier. However, we are not
aware that this judgement was based on a detailed
structural analysis.
The Inspector notes that the steel girders which
support the external brickwork may have corroded,
but that this is external work and does not affect the
real interest of the building which is the concrete frame
within. However, it is noted that this view is presented
without the supporting evidence provided by a full
structural survey of the building, and that the arches
are not constructed from reinforced Concrete, as
asserted.
A structural survey and appraisal of the whole building
(as viewed internally and externally) was undertaken by
Jenkins & Potter, Consulting Engineers, in November
2000. This report notes that the buildings generally
comprise brick-clad steel columns supporting concrete
floor and roof slabs with solid brickwork infill walls.
The flat roofs are generally screed or asphalt covered.
The roofs on the main entrance, front, small pool and
boiler room wings also have steel framed glazed
skylights.
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The main pool roof above the internal arched concrete
encased steel portals comprises a concrete encased
steel frame infilled with painted rendered brickwork
walls. The tiered roof on three levels appear to be of
concrete rib and clay pot construction spanning
longitudinal reinforced concrete beams, with an asphalt
covering and hatches for services.
The report details the condition of the principal
elements of the building. Generally the concrete was
found to be reasonably durable though there were
areas of poor workmanship resulting in low cover and
honeycombing. The report notes a potential difference
in the condition of the concrete features found
internally and externally. Generally, the external
concrete was found to be in good condition and had
been protected by the application of renders. The
internal concrete cased steel structure was also said to
be in reasonable structural condition compared with
the internal reinforced Concrete elements.
Carbonation depths were found to have been variable
and not unreasonable given the age of the concrete.
Poplar Baths elliptical arches located in main bath hall
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