Three-layer foundation wall (termPIR® AL in cavity)

Junction function

A three-layer foundation wall is a continuation of the 3-layer construction down into the foundations — used for buildings with clinker façades (item 04 = lower clinker course). The logic is identical to that of above-ground walls (p. 40):

• Load-bearing leaf (item 02) + insulation (item 03) + clinker cladding leaf (item 04) + connecting ties (item 05).
• Bituminous waterproofing (item 07) additionally applied externally — as in the 2-layer version.
• Cladding leaf (item 04) often made of water-resistant clinker (class GL); cement render between cladding and insulation (item 06) as an auxiliary layer.

Critical installation aspects

• termPIR® AL in the cavity — full-surface bonded with PUR adhesive to the load-bearing wall; ties do not penetrate the board (the tie connects the leaves, with insulation “in between”). The board is fitted so the tie does not cross its edge.
• Stainless steel tie (item 05) — only AISI 304/316 stainless steel; galvanised ties will corrode within 5–10 years in moist ground.
• Bituminous coating (item 07) on the outside of the cladding leaf — protects the cladding from capillary rise; in the 3-layer build-up the waterproofing is on the outer face of the cladding (not between load-bearing leaf and insulation as in the 2-layer version).
• Dimpled membrane (item 08) — provides continued mechanical protection and drainage.
• Horizontal damp-proof course (item 09) — at floor slab level; without it, capillary rise into the above-ground walls leads to salts, efflorescence and mould.
• Clinker plinth — the lower band of the cladding leaf made of frost- and water-resistant clinker class GL (water absorption <0.5%); jointed with frost-resistant mortar.
• Perimeter drainage (item 11) — perforated DN 100 pipe, gravel bedding, geotextile; at strip foundation level.

Documentation

Technical Catalogue termPIR® — Residential Buildings (Gór-Stal 2022), page 43 — Three-layer foundation wall (light-type waterproofing). Scale 1:10.

Components in this junction