Two-layer foundation wall (termPIR® WS + bitumen)

Junction function

Two-layer foundation wall with termPIR® WS = standard solution for a house without a basement, with a foundation wall 60–100 cm high. Layers:

1. Bituminous waterproofing coating (item 03) — e.g. Botament BE 901, Bibrol BIT-IN, Sopro AEB; 2 coats with a 24-hour interval, 2.5 mm total thickness.
2. termPIR® WS panel (item 04) — bonded directly to the second, still-wet bitumen coat; no technological gap — the bitumen acts as adhesive.
3. Dimpled foundation membrane (item 05) — protects against mechanical damage during backfilling + drains capillary water.
4. Perimeter drainage (item 07) — DN 100 perforated pipe around the foundation, gravel bed, geotextile; discharge to a manhole.

Critical installation aspects

• termPIR® WS — water resistance category W2L per PN-EN 1604 — withstands moisture contact for 28 days without loss of parameters (laboratory tests); HOWEVER does not withstand long-term exposure to groundwater — hence bituminous waterproofing is mandatory.
• Adhesive = bitumen — the WS panel is bonded to the second wet bitumen coat (3–15 min after application, depending on temperature); full-surface bonding + light manual pressing.
• Dimpled membrane (item 05) — orientation dimples facing outward (away from the wall, towards the ground); termination at plinth level covered with a starter profile.
• Perimeter drainage (item 07) — DN 100 perforated pipe AT THE LEVEL OF THE FOUNDATION FOOTING (not 50 cm higher, as is sometimes done); 1% slope towards the inspection manhole / stormwater drain.
• Plinth (item 06) — finishing layer bonded on mesh; minimum height 30 cm above ground level to protect against splashing; adhesive + 2 layers of reinforced render.
• Ground slope away from the building — minimum 2% within a 1 m strip to drain rainwater away from the foundation.

Documentation

Technical Catalogue termPIR® — Residential Buildings (Gór-Stal 2022), page 42 — Two-layer foundation wall (light-type waterproofing). Scale 1:10.

Components in this junction