Balcony in three-layer wall (termPIR® AL + ETX + WS)

Junction function

Balcony in a three-layer wall = a problem analogous to ETICS (page 39), but the cladding structure is less flexible: clinker brick does not allow easy embedment of Schöck balcony prefabricated elements. Hence the balcony is most often recessed into the floor ring beam (the balcony slab is an extension of the room floor slab).

Three layers of termPIR® used simultaneously:

• termPIR® AL (item 02) — main wall, within the cavity of the three-layer wall.
• termPIR® ETX (item 06) — balcony soffit, plastered from inside the recess (from below); it must have this function because ETX has an ETA for plastering.
• termPIR® WS (item 09) — under the balcony floor, waterproof (class W2L per PN-EN 1604); withstands the wet conditions of the balcony.

Critical installation aspects

• Waterproofing (item 08) — the most important element; SBS heat-welded membrane 5 mm with a 30 cm overlap onto the wall (under the cladding plinth) + 20 cm onto the aluminium drip edge. Without properly executed waterproofing, the balcony will suffer guaranteed damage within 5 years.
• Aluminium drip edge (item 14) — 30 mm beyond the balcony edge; without it, water seeps under the balcony → destroys the ETX (item 06) and the cladding fascia.
• Sloped layer (item 16) — sloped screed 1.5% towards the drip edge; without slope → ponding → frost damage to the surface.
• Plinth (item 13) — minimum height 15 cm; in the three-layer wall the plinth is of external clinker (continuation of the cladding) + epoxy silicone sealant.
• Balustrade (item 15) — anchored in the balcony slab edge from the outside; NEVER in the screed (item 11) or in the cladding ring beam (item 03).
• Ring beam and floor slab (item 17) — a strip of termPIR® AL run around the full perimeter of the ring beam; without this, a linear thermal bridge in the ring beam = condensation on the floor slab corner inside.
• Mineral plaster under the balcony (item 07) — on reinforcing mesh, light colour (>20% reflectance) to avoid overheating the ETX in summer >70°C (causes expansion and plaster cracking).

Documentation

Technical Catalogue termPIR® — Residential Buildings (Gór-Stal 2022), page 41 — Three-layer wall, balcony detail, vertical section. Scale 1:10.

Components in this junction