Heritage wall AL GK — glued installation (horizontal section)

Junction function

Corner detail of internal heritage insulation — the horizontal section shows what happens at the junction with the perpendicular wall (item 06). The transverse wall may be:

• An internal partition wall (10–15 cm, less thermally significant).
• An internal load-bearing wall (25–40 cm, significant thermal bridge).
• A stairwell (usually unheated, important insulator towards the warm side).

Regardless of the type of transverse wall, the junction geometry requires an expansion gap (item 07) filled with low-expansion PIR foam — this eliminates thermal movement of the materials and does not damage heritage stucco work.

Critical installation aspects

• Expansion gap (item 07) — 5–15 mm around the entire perimeter of the AL GK board; filling exclusively with low-expansion PIR foam (expansion <10%).
• Concealing trim (item 08) — wooden (typical for heritage interiors), acrylic finish, or decorative cornice (with stuccoed ceilings). Aesthetic match to the interior is mandatory (conservator approval!).
• Wall meeting point (items 01, 06) — before bonding, sand and prime the surface of the transverse wall along a 10 cm strip; without this, the adhesive will not grip the dust of historic paints.
• Thermal bridge on the transverse wall — WUFI analysis will reveal the risk of condensation within 30 cm of the corner; an additional strip of insulation 30 cm wide on the transverse wall (also AL GK, glued) is often sufficient.
• Adhesive (item 04) — full-surface, never spot application; PCI Pecimörtel or Ceresit CT 84 foam adhesive.
• Joint finish — between the AL GK board and the transverse wall → corner tape for plasterboard (perforated metal) + filler; standard plasterboard installation.

Documentation

Technical Catalogue termPIR® — Residential Buildings (Gór-Stal 2022), page 53 — Heritage wall AL GK, horizontal section, glued installation. Scale 1:10.

Components in this junction