Kadıköy, Istanbul · Dilovası plant & warehouse · London office +90 216 545 60 00 +44 7920 259866
Omega Steel Co.Steel supplier · Turkey

Wall Sandwich Panels

A wall panel is the building's face and its insulation in one 40–150 mm slab — flat enough for an office, tough enough for a warehouse, hygienic enough for a dairy. It is the second-largest volume our panel line makes after the roof panel, and the one architects ask about first.

Flat · micro-rib · linedPIR · PUR · rockwool40–150 mmTongue-and-grooveVisible or secret fix
Manufactured in our Dilovası plant Updated for the September 2026 list Lead time Stock thicknesses and colours: 5–10 working days; special cores, colours and lengths 2–3 weeks MOQ 300 m² per type and thickness

What is Wall sandwich panel?

A wall sandwich panel carries no water and can therefore be flat: its skins are lightly profiled — micro-ribbed (1 mm waves at 20–50 mm), lined (shallow grooves at 100–200 mm) or plain flat with a stucco-embossed surface — for stiffness and appearance rather than drainage, and its long edges are formed into a tongue and a groove that lock the panels together, house a factory-applied PE or PU gasket, and, on the secret-fix (hidden-fix) version, hide the screw inside the joint so the façade shows no fasteners. The panel mounts horizontally on columns or vertically on girts, spanning 3–6 m depending on thickness and wind load, with the core taking the shear and the joint transferring load between panels; a 60 mm PIR wall panel spans 4 m at 0.6 kN/m² wind. Cores are the same three as the roof — PIR (λ 0.022, B-s1,d0) as standard, PUR for economy, rockwool (A2-s1,d0, 100–120 kg/m³) where fire compartmentation or the insurer requires it; thickness runs from 40 mm on unheated sheds through 50–60 mm (the market standard) to 80–100 mm for heated buildings and cold stores and 120–150 mm for the energy codes and freezer rooms. Skins are PPGI 0.50 outer / 0.40 inner (0.60 / 0.50 on secret-fix and long spans) in RAL 9002 as standard, 7016 and 9006 for architecture, 9010 food-grade inside for food plants; the same panel with a flat inner face and PVC-sealed joints becomes a cold-store or clean-room wall. Flashings — base channel, corners, window and door frames, parapet — are folded from the same coil, and we supply the fixing screws, gaskets and sealants in the kit. Standard cover 1 000 mm; 1 150 mm on request; lengths 2–14 m.

Grades, standards and tolerances

Wall sandwich panel — steel grades and standards
Grade / standardYield (MPa)Note
PIR core, 40 kg/m³, λ 0.022standard; B-s1,d0
PUR core, 40 kg/m³, λ 0.024economy; B-s2,d0 / B-s3,d0
Rockwool core, 100–120 kg/m³, λ 0.040A2-s1,d0, fire walls, EI 30–120
Skins DX51D / S250GD + Z100–Z275 + PPGI≈ 140 / 250EN 10346 / EN 10169

CE-marked to EN 14509; rockwool wall panels carry an EI fire-resistance classification per EN 13501-2 on request.

Thickness, U-value and span

Wall panel, PIR core, 0.50 / 0.40 mm skins — thermal and structural data (guide; CE tables per project)
ThicknessU-value (W/m²K)Weight (kg/m²)Girt spacing at 0.5 kN/m² windat 0.8 kN/m²at 1.2 kN/m²
40 mm0.529.63.4 m2.8 m2.3 m
50 mm0.4210.03.9 m3.2 m2.6 m
60 mm0.3510.44.3 m3.6 m2.9 m
80 mm0.2711.25.0 m4.2 m3.4 m
100 mm0.2112.05.6 m4.7 m3.8 m
120 mm0.1812.86.1 m5.1 m4.2 m
150 mm0.1413.96.7 m5.6 m4.6 m

Single-span, L/100, horizontal or vertical; rockwool panels span about 15 % less and weigh 15–26 kg/m². Secret-fix panels use 0.60 mm outer skins for the same spans.

Faces, joints and fixing systems

Wall panel options
OptionDescriptionUse
Micro-rib face1 mm waves at 20–50 mm on both skinsthe standard industrial face; hides oil-canning
Lined faceshallow grooves at 100–200 mmarchitectural, horizontal lines
Flat (stucco-embossed) faceplain skin, embossedcold stores, clean rooms, offices
Visible fixscrew through the panel face into the girt, cappedindustrial, cheapest, fastest
Secret (hidden) fixscrew inside the tongue-and-groove jointarchitectural façades, no visible fasteners
Tongue-and-groove with PE gasketfactory-applied seal in the jointstandard airtightness
PVC / PU-sealed jointPU foam or PVC profile in the jointcold stores, hygienic rooms
Horizontal / vertical layingon columns / on girtsper design; horizontal hides girts

Corner, base, parapet and window flashings folded from the same coil in the same colour batch.

Skins, coatings and colours

Facing steel options on our panels
SkinThicknessZinc / paintWhere
PPGI PE 25 µm0.40 / 0.50 / 0.60 mmZ100–Z140, RAL 9002 / 9010 / 3009 / 7016 …outer and inner face standard
PPGI SMP / PVDF0.50 / 0.60 mmZ140–Z275coastal, Gulf, colour warranty
Galvanized0.40 / 0.50 mmZ140–Z275, unpaintedinner face on a budget
Food-grade PE0.50 mmZ140, RAL 9010food, cold-store interiors
Aluzinc / aluminium0.50 / 0.60 mmto order

Outer skin profiled (micro-rib, lined or 5-rib roof); inner skin micro-ribbed or flat.

Lengths and stock

PIR wall panels 50, 60 and 80 mm micro-rib 9002/9002 with 0.50/0.40 skins are produced continuously (5–10 working days, any length to 14 m); 40, 100–150 mm, secret-fix, rockwool, flat-face and other colours in 2–3 weeks. Corner, base, parapet and window flashings, screws, gaskets and sealant ship with the panels.

Fixing, joints and installation

Start from a level base channel with a PU seal; place panels tongue into groove and press home, apply the joint sealant where the design requires airtightness; fix with 5.5 mm self-drilling screws long enough for panel + girt (two per panel per support for visible fix, one in the joint for secret fix, with 16–19 mm washers), minimum 50 mm from the panel end. Horizontal panels are fixed at every column; vertical panels at every girt (3–6 m). Cut with a fine-tooth circular saw or cold saw; openings are cut on the ground and framed with folded flashings. Lift with vacuum lifters; keep the film on until the flashings are fitted, remove within 3 months.

Where it is used

  • External walls of warehouses, factories and logistics halls
  • Commercial, retail and office buildings (architectural faces)
  • Cold-store, freezer and food-plant walls and partitions
  • Clean rooms, laboratories and hospitals (flat face)
  • Fire compartment walls (rockwool, EI 30–120)
  • Prefab housing, site offices and modular buildings

Wall panel vs roof panel vs cladding sheet

The roof sandwich panel has a 5-rib skin and an overlap joint for water; the wall panel is flat with a tongue-and-groove and can be secret-fixed. Against a built-up wall (T27 sheet + insulation + liner) the panel is faster and airtight. Cores: PIR, PUR, rockwool; cold-store walls on the cold room panel page.

Price

Wall panels are priced per m² by thickness, core, face and fixing system on the panel list; visible-fix micro-rib PIR 50 mm is the reference, secret-fix adds about 10 %, rockwool 20–30 %. The bands below are the month\'s indicative FOB Istanbul ranges for 50 and 80 mm PIR; flashings per metre.

Wall panel PIR 50 mm10 – 18USD/m² · FOB Istanbul
Wall panel PIR 80 mm18 – 20.5USD/m² · FOB Istanbul

Bands from our weekly export list (September 2026), FOB Istanbul, full-container quantities, excluding freight and certificates. Firm price per project on RFQ within one working day.

Export and packing

Wall panels are stacked 10–15 per pack face-to-face with foam separators and PE film on both skins, strapped on timber bearers with edge protection and PE-wrapped, labelled with type, core, thickness, face, colours, length and count; a 40' HC takes about 450–600 m² of 50 mm wall panels, thicker panels less; 12–14 m panels on flat-racks or by covered truck. Flashings and fixing kits in the same load. HS 7308.90 / 9406.

TermDetail
MOQ300 m² per type and thickness
IncotermsFOB Istanbul · CIF / CFR Gulf, Africa · DAP EU, Balkans, Iraq, Caucasus · DAP Aktau
Lead timeStock thicknesses and colours: 5–10 working days; special cores, colours and lengths 2–3 weeks
PackingPanels stacked 8–15 per pack with foam separators, PE film on both faces, strapped on timber bearers, PE-wrapped
Container / truck40' HC ≈ 400–550 m² of 50 mm panels (volume-limited); 12 m panels on flat-rack or by truck to Iraq / Caucasus
DocumentsInvoice, packing list, EN 10204 3.1 (skins), CE DoP (EN 14509), fire classification report, certificate of origin; SASO / SONCAP on request
Payment30% advance, balance against B/L copy; L/C at sight above 100 t

Certificates

Panels ship with the CE declaration of performance under EN 14509, the skin coil EN 10204 3.1 certificates, the EN 13501-1 reaction-to-fire report and — for rockwool fire walls — the EN 13501-2 EI classification; joint airtightness and acoustic (Rw) data on request.

How to order

Specify core, thickness, face (micro-rib / lined / flat), fixing (visible / secret), outer and inner skins and colours, laying direction, panel lengths and quantities (or elevations for a cutting list), flashings, openings and destination.

Standards

  • EN 14509 — self-supporting double-skin metal-faced insulating panels
  • EN 13501-1 fire classification; EN 13165 (PIR/PUR), EN 13162 (mineral wool), EN 13163 (EPS) cores
  • EN 10169 / EN 10346 skin steel
  • EN 10204 3.1

Grades

Grade data sheets (chemistry, mechanicals, equivalents) are on our reference site: DX51D · S250GD · S280GD

Frequently asked questions

What is a wall sandwich panel?

An insulated cladding panel: two flat, micro-ribbed or lined steel skins around a PIR / PUR / rockwool core 40–150 mm, with a tongue-and-groove joint, mounted on girts or columns at 3–6 m, visible- or secret-fixed.

What is the difference between wall and roof panels?

Roof panels have a 5-rib outer skin and an overlapping joint to carry water; wall panels are flat with a tongue-and-groove joint and can hide the fixing. They are not interchangeable.

What is secret-fix (hidden-fix) panel?

A wall panel whose screw sits inside the tongue-and-groove joint so no fastener shows on the façade; it uses a 0.60 mm outer skin and costs about 10 % more.

What thickness of wall panel?

40–50 mm for unheated sheds, 50–60 mm as the standard, 80–100 mm for heated buildings and cold stores, 120–150 mm for energy codes and freezers.

Can wall panels be used as fire walls?

Rockwool-core wall panels achieve EI 30–120 fire resistance and A2-s1,d0 reaction to fire; PIR panels are B-s1,d0 and not fire-resisting.

What is the price of wall sandwich panel?

Per m² FOB Istanbul by thickness, core and fixing — see the bands above.