283757893275

Single-Storey Frames, Shells and Lightweight Coverings 233
Pressed steel capping
fixed to parapet
Steel saddle
fixed to
parapet and
dressed over
joint
Insulation and
vapour check
Steel closer fixed
over parapet
Steel closer fixed
under decking
and up parapet
Profiled steel
cladding
Insulation
Profiled steel
internal lining
Secondary beam
Built-up bitumen felt roofing
on insulation board on
vapour check on profiled
steel decking
Steel capping fixed
over expansion joint
Steel upstands
fixed to deck
to support
insulation board
and built-up
felt around
expansion joint
Main
beams
Figure 4.72 Parapet and expansion joint to profiled steel decking covered with built-up
bitumen felt roofing.
detailed guidance on fixing, exposure and durability, together with conformity to relevant
standards and product guarantees.
4.3 Rooflights
The traditional means of providing daylight penetration to the working surfaces of large
single-storey buildings is through rooflights, either fixed in the slope of roofs or as upstand
lights in flat roofs. With the increase in automated manufacturing and artificial illumination,
combined with concerns over poor thermal and sound insulation, unwanted glare,
solar heat gain, and concerns over security, the use of rooflights has become much less common.
Functional requirements
The primary function of a rooflight is to allow the admission of daylight. As a component
part of the roof, the rooflight also has to satisfy the functional requirements of the roof,