Balcony in ETICS termPIR® ETX — vertical section

Junction function

A reinforced concrete balcony built into the wall = the worst thermal bridge in a single-family house. The balcony slab is a concrete extension of the room floor slab with lambda 1.7 W/m·K (vs ETX 0.022) — without proper insulation: condensation at the internal floor slab corner, mould growth, “cold feet” on the floor next to the balcony.

Comprehensive solution per the catalogue:

1. Balcony soffit insulation (item 06) — a termPIR® ETX strip continued beneath the entire balcony slab.
2. Waterproofing (item 08) — heat-bonded bitumen membrane or bitumen sheet across the entire balcony surface + 20 cm overlap onto the skirting + 30 cm onto the wall beneath the ETX.
3. termPIR® WS floor insulation (item 09) — beneath the balcony screed (WS = waterproof, for wet floors); insulation of the underside of the screed — reduces the thermal bridge through the slab.
4. Falls layer (item 16) — screed to falls 1.5% towards the drip edge (item 14).

Critical installation aspects

• Waterproofing (item 08) — the most crucial element; if poorly executed, water seeps under the insulation → capillary uptake into the wall → render falling off within a year. SBS heat-bonded bitumen membrane 5 mm butt-jointed + minimum 10 cm overlaps; alternatives: Kerakoll Aquastop, Maris BS-9 (liquid membrane in 2 coats).
• Aluminium drip edge (item 14) — projects 30 mm beyond the balcony edge; without the drip edge water seeps under the balcony and destroys the soffit insulation.
• Fall 1.5% (item 16) — towards the drip edge; without the fall, water pools on the balcony surface + capillary uptake at the balustrade fixings.
• Skirting (item 13) — minimum height 15 cm, always bonded beneath the waterproofing (NOT on top of the waterproofing); joints sealed with epoxy silicone.
• Balustrade (item 15) — anchored in the front edge of the balcony (preferable) or in the balcony slab with a dedicated sealing compound; NEVER anchor in the screed — it will pull out after the first winter.
• Clinker tiles (item 12) — frost-resistant per PN-EN 14411 class GL (water absorption <0.5%); on flexible adhesive C2TE S1 (Kerakoll, Mapei Adesilex).
• Ring beam and floor slab (item 07) — continuity of ETX with the balcony from below is required; an ETX strip around all edges of the ring beam to close the perimeter insulation.

Documentation

Technical Catalogue termPIR® — Residential Buildings (Gór-Stal 2022), page 37 — Two-layer ETICS wall, balcony detail, vertical section. Scale 1:10.

Components in this junction