Article Bouwwereld on set of big skylights in Pamplona Spain with special requirements on fireclassification EN13501-1, thermal isolation, solar factor and light transmission

1. Dutch knowhow in Spanish
polycarbonate roof
Dutch expertise has made it possible in a shopping centre in the Spanish city of Pamplona to replace the old
plastic rooflights with new composite cassettes of solid polycarbonate sheeting. The new cassettes meet high
standards of fire resistance, strength, reduction of heat buildup and thermal insulation of building innerclimate.
In Pamplona the seven large double
curved plastic roof lights measuring 17
metres x 7.5 metres from a large shop-
ping centre were to be replaced. The old
material was severely affected by UV
radiation, unpleasantly yellowed, mechan-
ically deteriorated and needed to be
replaced. SRT Plastics (Bergen op Zoom /
The Netherlands) delivered new material
to a much higher specification compliant
with modern and higher quality require-
ments. Apollo France Diffusion pre-as-
sembled the cassettes and mounted the
pre-fabricated units directly onto the roof.
Important in the construction of the roof
was the outer sheet of 8 mm. This was
the thickness of the old outer sheet and
was constructively needed again because
of the existing structure, span, snow &
wind loads. But this polycarbonate solid
sheet needed to comply with current fire
standards which evolved since the last
installation. Solid polycarbonate sheets
up to 6 mm in thickness normally comply
with these standards but in the case of
thicker sheets the amount of energy in
the sheet material is so large that it be-
comes less self extinguishing. There was
no validated solid polycarbonate sheet of
8 mm on the market to meet the fire resis-
heat-reducing properties, a bottom sheet
of 5 mm and a centre sheet of 3 mm is
added with a space of 20 mm separating
each of the sheets. This build-up makes
the roof compliant with modern require-
ments of, in particular, insulation value.
Also the edge seal is of higher quality by
using plastic spacing profiles connected
by high adhesion double-sided tape to
the sheets. At top and bottom end the
cassettes are open to the atmosphere by
filtered channels to ventilate and dis-
charge moisture since polycarbonate is a
hygroscopic material. The whole cassette
is mounted on the supporting construc-
tion of the roof with aluminum profiles.
Prevent heat up of inner climate
In Southern European countries like
Spain, heat build up of the inner climate
through excessive solar heat gain is an
important factor. Therefore, in addition to
the unique 8 mm top sheet with heat-
resistant properties, a very light opal tint-
ed solid polycarbonate 3 mm sheet was
applied as a centre sheet of the cassette,
which filters the radiation of the sun even
more. Initially, the lower sheet of 5 mm
could be carried out in opal, but that
would mean too much reduction of light
transmission. A very light tinted opal
polycarbonate in 3 mm sheet, specially
designed for rooflight and dome applica-
tions, with high light transmission of
around 70% was specified by SRT Plas-
tics. In the past polycarbonate opal
sheets were less UV-resistant, but tech-
nology has improved and they are now in
the right durable quality available.
The sheet materials in the cassette have
a combined light transmission Tv of
29,4%, UV-transmission Tuv of 0%, Solar
factor g of 31% and a U-value of 1,657 W/
m2K.
In spite of occasional negatives heard
against the use of polycarbonate over
tance requirements. At this moment and
as far as our knowledge reaches, SRT
Plastics is the only european supplier
having this unique sheet in their produc-
trange.
Own development
This 8 mm thick certified fire resistant
sheet material was developed previously
by SRT Plastics for the renovation of a
roof of a shopping centre in Nantes,
France, for which the same fire rating,
Cs3d0 on EN 13501-1, was required. This
corresponds to former French fire class
M2 (NF.P92-501 & NF.P92-505) with
which the old deteriorated 8 mm sheet
officially still complied. Due to the new
interpretation of the regulations no new
solid polycarbonate sheet could be found
with this fire rating. SRT Plastics decided
to develop this sheet themselves and
configured, designed and produced this
sheet according to their specifications.
The unique european fire rating certifi-
cate on 8 mm polycarbonate sheet is in
the name of SRT Plastics.
Where the old glazing was only two lay-
ers the new composite cassette features
3 layers of solid polycarbonate sheets. In
addition to the upper sheet of 8 mm with
32 // Bouwwereld
Tekstproductie Henk Wind // Fotografie SRT Plastics
// Tekenwerk Henk Heusinkveld
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2. Kunststof kokers
820
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205
Warmtewerend polycarbonaat
Opaal polycarbonaat
1:5
glass in rooflight applications (e.g. less
lifespan), there are many advantages.
Polycarbonate is much lighter, half the
weight of glass, reducing materials & cost
in supporting structures in both new con-
structions and renovations. In polycarbon-
ate, it is possible to influence properties
like colour, diffusion, heat reduction, as-
pect etc, in a very efficient way. We have
many possibilities to produce to a re-
quested size with standard width 2050 to
2100 mm with lengths of up to 8 metres in
solid sheet and up to 13 metres in multi-
wall sheet. SRT Plastics polycarbonate
sheet is simple to convert and process by
secondary operations like cutting, routing
and drilling, easy to be cold curved, and
installation is relatively straightforward
onto the roof due to the lower weight and
with less risk of breakage.
1 // On the roof of the shopping centre with
7 skylights each measuring 17 metres x
7.5 metres, with each 17 curved roof cassettes.
2 // The results of the new roof is much bet-
ter light transmission, higher thermal isolation
and less heat build-up in the climate of the
inner building. 3 // In progress: Left the old
roof, beside that the new roof with SRT Plastics
polycarbonate sheet materials.
Projectdata // Location: Galeria La
Morea, Pamplona // Principal: Galeria
La Morea, Pamplona // Design &
installation: Apollo France Diffusion
(part of the Hak4t Groep), Nantes,
apollo-france-diff.com // Supplier
polycarbonate sheet: SRT Plastics
International BV, Bergen op Zoom,
srt-plastics.com // Installation period:
september – oktober 2016
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Product //
Bouwwereld //
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