Window — insPIRe® U sandwich panel (horizontal layout, concealed fastening)

Junction function

Window in a wall of insPIRe® U sandwich panels in horizontal layout — panels arranged horizontally + concealed U joint = the most minimalist window opening geometry in the sandwich panel range.

Analogously to the horizontal S layout:

• Panels above the window (item 01 upper) — continuous, with the lower edge meeting the window frame.
• Panels below the window (item 01 lower) — continuous, with the upper edge meeting the sill.
• Side panels — interrupted around the window perimeter, requiring OB-01 + OB-02 flashings.

Difference vs horizontal S layout: no visible panel fasteners on the facade (they are concealed within the U joint) — only the flashing fasteners OB-01/OB-02 securing these components to the frame remain visible around the opening.

Critical installation aspects — specific to horizontal U layout

• Panel division at the opening — horizontal panels are not cut vertically, unlike the vertical layout. The window frame edges determine the panel module height (e.g. a 1.2 × 1.5 m window requires a 1.5 m high module within the opening zone).
• OB-37 window sill (item 07) — in horizontal layout the sill rests directly on the lower panel (flat U-panel surface, easy installation). 5% outward slope, 30 mm drip edge.
• Upper edge of the opening — OB-01 corner flashing conceals the joint between the upper panel and the frame; the PES gasket (item 08) at the panel interface is critical (flat U surface vs stepped S surface).
• Window side edges — analogous to vertical layout: frame liner + OB-01/OB-02 + foam + silicone.
• Edge zone of the opening — double fastener density within a 30 cm strip, mounted in the U panel joint (concealed).

Horizontal U vs Horizontal S layout

Aspect	U (horizontal + concealed)	S (horizontal + visible)
Number of cut panels	only 2 sides (left+right) — unchanged	same
Visible panel fasteners	none	present around the opening
Facade aesthetics	maximally linear, premium	linear industrial
Ease of flashing installation	higher (flat U surface)	baseline
Price per opening	+20-25% vs S	baseline
Typical applications	car showrooms, office buildings, eco-buildings	retail halls, warehouses

Occurs in the system insPIRe® U concealed hall wall.

Documentation

Gór-Stal Technical Catalogue 2025, p. 76 — window in horizontal layout, Variant I, vertical section, U panel.

Components in this junction