Construction details
4 5 6 7 8 3.3 Architectural details
Flat roof junction
3
3.3.1 Concrete construction
3.3.2 Timber construction
12 3.3.3 Steel construction, penetration
2
11 3.3.4 Steel construction with fascia plate and
9
sunshade
1
13 Vertical sections
scale 1:5
Typical details of various flat roof junctions with
different architectural and constructional char-
11 acteristics plus different materials are shown on
this and the next page.
Fig. 3.3.1. The primary structure here is rein-
forced concrete. The edge of the slab and the
overlying roof construction are clad with a steel
plate attached to the concrete. The posts are
14 fixed to angles welded to this plate. The con-
nection of the upper facade rail to the edge
plate is impervious to air and vapour diffusion.
The clearance between glazing and plate to
the front edge of roof slab should be wide
enough to allow cleaning of the glass. Heat
reflected back from the edge of the slab could
lead to stresses in the glass caused by varying
3.3.1 heating effects. A stationary layer of air can
4 5 8 lead to condensation occurring. Suitable venti-
1 Double glazing lation at the parapet, e.g. by including ventila-
2 Aluminium facade rail tion louvres, should be considered at the plan-
3 Plastic spacer block
4 Sheet metal cleat ning stage.
5 Vapour barrier (EPDM sheeting) Fig. 3.3.2. The primary structure here is an
6 EPDM pad insulated timber frame; timber panels form the
7 Thermal insulation fascia. The junction with the facade is achieved
9
8 Anodised aluminium sheet
9 Roof construction:
in two ways: in the plane of the glass by a
chippings clamped plastic block, and in the structural
waterproofing plane by an insulated aluminium hollow section
thermal insulation with thermal break. The connection must be
vapour barrier able to accommodate movements in the facade
10 Glulam beam
11 Steel angle as well as deformation of the primary structure
12 Vapour barrier caused by imposed loads, thermal expansion
13 Sheet steel etc. It must also remain impervious to air and
14 Bolt in elongated hole 18 10
vapour diffusion, and must be thermally insu-
15 Permanently elastic seal
lated.
16 Aluminium section, insulated,
with thermal break 7 Fig. 3.3.3. The primary structure here is steel.
17 Movement joint The facade posts are fixed to the main struc-
18 Plywood, with waterproof adhesive ture via steel angles. The steel beams penetrat-
19 Joist hanger 5
ing the facade are thermal bridges. Condensa-
20 Aluminium angle bolted to supporting
construction tion may occur and should be drained away in
21 Fabric sunshade a controlled manner (e.g. condensation chan-
22 Steel bracket 3 15 19 12 nel). The joint between external skin and beam
23 Insulated facade panel 16 must be able to accommodate the various
24 Cast-in slotted channel
movements of the facade and loadbearing
25 Special perforated steel beam
26 Stainless steel plate, bolted on structure (especially thermal expansion and
1 2
27 Steel tube wind loads). It must also be impervious to air
28 Steel trapezoidal profile sheeting and vapour diffusion. It is normally covered by
a stainless steel sleeve fitted to the outside.
3.3.2
184
