General
Flat roofs: special structures

Special works include :

• reliefs: reliefs are defined as low acroteria where the height above the protection is less than 30 cm, high acroteria where the height above the protection is less than 30 cm, upstands which are reliefs along a structural joint or around a skylight or cupola, floor recesses, stumps, through pillars, studs, plinths and gondola supports, thresholds and projections, aediculae and miscellaneous premises, and overhangs. Above the waterproofing upstand, they must include a structure that deflects run-off water, such as a projecting fascia, a groove, a spoiler and recess, a flashing, a coping or coping cap (figure 1 );

• flat or upstand joints, expansion or break joints in...