In Indonesian tender packages the sandwich panel clause is often a single line: wall panel, 75 mm, fire rated. But a panel is an assembly, and each layer carries its own number. State only the total and bids cannot be compared, the committee has no ground to reject what arrives, and the contractor is exposed to protest. This guide sets out which clauses belong there, which standards to cite, and which numbers are better left as ranges.
What a tender document may and may not name
For Indonesian government procurement, Presidential Regulation 46/2025 - the second amendment to Regulation 16/2018, in force from 30 April 2025 - rewrote Article 19. When drafting technical specifications, the procurement officer is directed towards domestic products, products carrying an Indonesian National Standard, micro and small enterprise output, and environmentally sound products.
The same article limits brand naming to components, spare parts, part of an existing system, or goods in the electronic catalogue and online shop, and ties domestic sourcing to actual industrial capability per the inventory list issued by the Ministry of Industry. The consolidated text sits at the national legal documentation portal. In practice: write performance and numbers, not a factory name. Local content is a separate subject, covered in our guide to TKDN rules for panel tenders.
Clauses that belong in a wall, partition and ceiling spec
The panel line here covers external walls, internal partitions and room ceilings such as cold rooms and cleanrooms; long-span roof structures and canopies are handled by separate roofing materials outside this line. The clauses below make competing bids comparable line by line.
- Core type - PU, PIR, EPS or stone wool, named explicitly; thermal values and fire behaviour differ widely.
- Nominal thickness and tolerance - a working range of 50-150 mm for every core type, one figure per room type.
- Core density - EN 14509 Annex A.8 sets out how to measure it, not a minimum, so the client states the number.
- Steel facing thickness with its basis - BMT, TCT or APT; pick one and name the term.
- Metallic coating mass - a Z or AZ class to EN 10346, not the single word galvanised.
- Paint system - type and dry film thickness, plus a colour code where appearance matters.
- Reaction to fire class with its standard number - see the next section.
- Dimensional tolerances and documents to be submitted - accessories and fasteners included.
Fire class: two standards that get swapped
EN 13501-1 classifies reaction to fire: classes A1 through F, plus smoke codes s1 to s3 and flaming droplet codes d0 to d2. So B-s1,d0 means limited contribution to fire, the lowest smoke class and no flaming droplets. EN 13501-2 measures something else, the fire resistance of an assembly, reported as EI plus a number of minutes.
The two are independent: a good surface class does not mean a long EI rating. An EI figure is tied to the complete assembly - core, thickness, installation direction, span, even wall height. One European datasheet lists EI 60 at 80 mm, EI 90 at 100 mm and EI 120 from 120 mm upwards, the last only for vertical installation up to a 4 m span.
So a specification should demand a standard number, not an adjective. A bare class A claim means little: GB 8624-2012 in China uses the same wording, and no official ruling makes it equivalent to A2-s1,d0. Many datasheets also record EN 13501-2 as NPD, meaning no performance was declared for that property.
Steel thickness and coating mass: state the basis
Facing thickness is the most commonly misread figure. BMT is base metal thickness, TCT the thickness after metallic coating, APT after painting. In BlueScope tables, BMT 0.42 mm corresponds to TCT 0.47 mm and BMT 0.48 mm to TCT 0.53 mm, a gap of roughly 0.05 mm, so a quoted 0.45 mm with no basis can describe two different products.
Coating mass deserves locking down too. Under EN 10346, Z275 means 275 g/m2 of zinc across both faces combined, with a triple-spot minimum of 235 g/m2, roughly 20 microns per side. Aluminium-zinc coatings come in AZ100, AZ150 and AZ185 classes; the heavier the coating, the longer the life in a corrosive environment.
Evidence documents you can legitimately demand
EN 14509:2013 is the harmonised standard for self-supporting double skin metal faced insulating panels; under it the manufacturer issues a Declaration of Performance and applies CE marking. It also requires the metal grade, facing thickness and tolerance system for each face, three items a tender document can request directly.
Domestically the only product standard for insulating panels is SNI 9186:2023, for PIR cores; EPS and stone wool have none. Aluminium-zinc coated sheet falls under SNI 4096:2019. Reading test reports is covered in the guide to panel certificates and datasheets.
Figures better left as ranges
Three items are often written too rigidly. First, thickness tolerance: one manufacturer catalogue uses plus or minus 2 mm up to 100 mm and 2 per cent above that, but those are catalogue values, not the standard, so ask for the declared tolerance on the supplier datasheet. Second, core density: nominal PIR figures run from 37.5 to 40 kg/m3, while wall stone wool lines quote minimums of 85 to 100 kg/m3.
Third, price. A mid-2026 survey of published price lists puts installed PU panel at 50-75 mm in the range of IDR 350,000-550,000 per square metre, with installation labour alone at IDR 150,000-230,000 per square metre. Treat those as budget brackets, not fixed prices. Note too that EN 14509 is being revised into two parts and those drafts are not yet in force, so the valid reference remains the 2013 edition.
FAQ: Frequently asked questions
May a tender document name a specific panel brand?
For government procurement, Article 19 limits that to components, spare parts, part of an existing system, or goods in the electronic catalogue and online shop. The safer route is to write performance figures, then accept an equivalent proven by datasheet and test report, approved in writing before ordering.
Is writing two hour fire resistance enough in a specification?
Not yet. Add the standard number and the test scope, for example an EN 13501-2 classification for a wall assembly with the installation direction and span tested. Without that, two bids using identical wording can refer to very different assemblies.
Ask us to review your project specification
If you are drafting a tender specification or assessing bids for wall, partition and room ceiling panels, we can help align the technical clauses first. Tell us the rooms, the fire class you target and your schedule through the sandwichpanels.id contact page, then ask for an itemised quotation with datasheets and test documents attached.
