Mannok's published floor-loading guidance lines up the commercial EPS grades as EPS 100 for general commercial floors and EPS 200 for cold-store floors, with declared compressive stress at 10% compression of 100 kPa and 200 kPa respectively per BS EN 826 [S1][S2].
Yetico publishes EPS 200 with a working-load ceiling of 6.0 t/m2, lambda 0.034 W/m.K, and board sizes 1000 x 500 mm from 10 mm in 10 mm steps, which is the same density class as Mannok's commercial-floor top grade [S4]. The full EPS board reference covers grades, water and fire behaviour, and selection under EN 13163.
Grade ladder and the loading cases that drive it
EPS is sold under a numeric grade that equals the declared compressive stress at 10% compression in kPa, tested to EN 826, so EPS 100 = 100 kPa and EPS 200 = 200 kPa; Mannok publishes the same ladder, with EPS 70 for domestic floors, EPS 100 and EPS 150 for commercial floors, and EPS 200 for cold-store floors [S1][S2].
Under that ladder the rough loading envelope is EPS 70 for domestic floor loads near 1.0–1.5 kPa, EPS 100–150 for retail and office floors typically 2.5–5.0 kPa, and EPS 200 for cold stores and heavy-commercial slabs where Yetico's 6.0 t/m2 working-load figure applies [S1][S4]. Specifiers should match the grade to the unfactored floor load plus a contingency for point loads from pallet trucks, racks, or vehicle traffic, because crushing at the panel edge is the dominant in-service failure mode.
Declared properties that decide a commercial spec
Mannok's NBS source entry for EPS 100 lists 0.036 W/m.K thermal conductivity (to BS EN 13163), 100 kPa compressive at 10% compression (to BS EN 826), 150 kPa bending strength (to BS EN 12089), DS(N)5 dimensional stability (to BS EN 1604), water vapour diffusion resistance 30–70, and water vapour permeability 0.010–0.024 mg/Pa·m·kg, all under EN 13163 [S2].
Compared with XPS board, EPS absorbs more water over the long term and has lower compressive strength per unit density, so on a wet plaza deck, an inverted roof, or a basement wall the spec usually shifts toward XPS regardless of cost.
White vs grey graphite, and the lambda trade
White EPS delivers thermal conductivity near 0.034–0.038 W/m.K, while grey graphite EPS (BASF Neopor type) drops to roughly 0.030–0.032 W/m.K at the same density, a 15–20% gain that lets the designer shave 15–20% off board thickness for the same U-value [S3]. The lambda gain is paid for in board cost, not in mechanical behaviour: density, compressive class, and water-absorption numbers are essentially the same as white at equal grade.
For a Part L target on a commercial floor, the practical move is to fix the grade against the load case first, then pick white or grey to hit the U-value at the lowest board thickness the floor build-up can accept. EPS board selection flows in that order, because under-specifying the grade and over-specifying the lambda gives a board that insulates but crushes.
Fire, facades, and what the datasheet will and will not tell you
Standard EPS is Euroclass F under EN 13501-1; with a fire-retardant additive the same Mannok EPS 100 board is rated Euroclass E, and the specifier must pick the additive variant on the NBS source entry rather than assume the rating is the default [S2]. On North American EIFS jobs, ASTM C 578 governs the Type I–XV density and compressive ladder, and a Dryvit-class system uses Type I board (minimum 0.90 lb/ft3, 10 psi) in 24 in × 48 in PB or 24 in × 96 in PM sheets, ≥3/4 in thick, with vertical adhesive ribbons and running-bond joints offset ≥6 in from sheathing seams per a 2026-07 spec-match guide [S5].
Code-listed submittals for North American projects typically reference ICC ESR-1349 for the foam-plastic insulation, and the supplier's U.L. classification card (R12290 Control 85TO Classification BRYX is one common control number for construction-grade EPS); both should be checked against the actual shipment, not the catalogue page [S5]. Where the assembly is a rainscreen or EIFS over a tall commercial facade, the fire stop at slab edges and the encapsulation of the board in a non-combustible finish are what limit flame spread, not the foam itself.
Cost, thickness, and the budget alternative to PIR
UK retail pricing in mid-2026 puts EPS70 at about £11.56 per 2400 x 1200 mm board at 100 mm thickness (≈ £4.0/m2 for 100 mm), EPS100 at £14.52 for 25 mm rising to £58.08 for 100 mm, and EPS150 at £20.26 to £81.02 across the same 25–100 mm range, with EPS 100 at 100 mm working out to roughly £20/m2 [S6].
Buildwiz's 2026 budget comparison frames EPS70 and EPS100 as the cost-down alternative to 100 mm PIR on a 24 m2 floor extension, with the trade-off being that EPS needs more thickness than PIR to hit the same U-value because lambda is roughly 0.034–0.038 W/m.K versus 0.022–0.024 W/m.K for foil-faced PIR, and EPS must be kept clear of electrical cable runs in the floor build-up [S8]. Sandwich-panel construction with an EPS core, sold as a factory-laminated alternative to site-built stud walls, runs a closed-cell water absorption of ≤4% and a service life of 15–20 years under normal maintenance, per a 2026 industrial-warehouse product sheet [S7]. For buyers weighing the insulation board family as a whole, the short version is: EPS wins on cost and embodied carbon per m2 per R-value, loses to XPS on water and compressive, and loses to PIR on thickness-to-U-value.
Selection criteria at a glance: EPS 100 vs EPS 150 vs EPS 200
On a commercial-floor spec the three grades most often compared are EPS 100, EPS 150, and EPS 200, and they line up against four decision criteria as follows: (1) declared compressive stress at 10% compression: 100, 150, 200 kPa per EN 826; (2) indicative working floor load: 2.5, 4.0, 6.0 t/m2; (3) typical applications: offices and retail, heavier commercial and light industrial, cold stores and plaza decks; (4) indicative cost per m2 at 100 mm in the UK mid-2026 market: roughly £20, £28, and £36 [S1][S2][S4][S6].
Specifying engineers should also screen the board against water exposure (if it is below grade or in an inverted roof, push to XPS regardless of grade), fire classification (default Euroclass F, upgrade to E with FR additive), cable contact (EPS in direct contact with electrical cables in floors is a code violation in most jurisdictions), and dimensional stability class DS(N)5 under EN 1604 for heated-floor applications [S2][S8]. A related decision map for hospital-grade applications, where the moisture and fire criteria tighten further, sits in the 2026 hospital XPS selection guide, which is useful as a counter-example when EPS is the wrong call.
Common pitfalls and acceptance checks on delivery
Three failure modes show up repeatedly on commercial EPS jobs: crushing at panel edges where the grade is undersized for the live load, moisture accumulation in below-grade or inverted-roof positions where the specifier picked EPS over XPS for cost, and fire-spread risk on facades where the board was left exposed at slab edges or service penetrations. On delivery, the batch should carry a CE mark to EN 13163, the declared grade and lambda on the label, a Euroclass rating (F or E), and the date code tied to the manufacturer's DoP [S2].
Acceptance on site should confirm the nominal density (for EPS 100 around 20 kg/m3 per Mannok's data), the board dimensions against the structural drawing, that boards are dry and undamaged at unwrap, and that they have been stored off the ground and under cover, because wet boards lose lambda performance until they re-equilibrate. A close-out note in the O&M manual should record the grade, the manufacturer, the DoP reference, and the lambda used in the U-value calculation, so the as-built thermal performance can be audited against the design.
Two signals worth tracking over the rest of 2026: the next revision cycle for EN 13163's declared-property tables, and any UK Part L consultation that tightens floor U-values on commercial buildings, both of which will move the cost-optimal EPS grade for new commercial builds. The EPS board encyclopedia page is updated when EN 13163 amendment text or new manufacturer data sheets land, and is the cleanest place to watch the lambda and lambda-vs-thickness trade for white and grey grades.