HDIII Wall System · Formwork Block · Infill

REI 120 Infill CE · ETA 08/0023

Isotex HD III 44/23 Graphite Wood-Cement Formwork Block

Code: HDIII-44/23

HDIII-44/23 is a 440 mm Isotex wood-cement formwork block with 230 mm graphite EPS and 120 mm concrete core. 44/23 has 120 mm concrete core; treat as infill/special high-insulation option unless engineer confirms load-bearing use.

0.11U-value W/m²K (2D)

13h 16'Phase shift

REI 120Fire rating

44 cmWall depth

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CE · ETA 08/0023 REI 120 EPD S-P-01472 EC8 seismic Bureau Veritas

Thermal performance

0.11 W/m²K (2D)

UNI EN ISO 6946 + UNI EN 10355. Independently tested by ITC-CNR. 3D value not published for this product.

EN ISO 6946NZEB ✓

Thermal inertia

13h 16' phase shift

Wood-cement and concrete mass absorbs heat by day and releases it at night.

EN ISO 13786

Acoustic performance

Rw 53 dB

Wood-cement absorbs noise at low and high frequencies simultaneously.

EN ISO 717-1

Fire resistance

REI 120

Load-bearing capacity, integrity and insulation maintained. Reaction to fire B-s1,d0. LEPIR II façade test passed.

NF EN 13501-2

01Overview

Compliance summary

✓ CE marked ETA 08/0023

✓ REI 120

✓ EPD S-P-01472

✓ EC8 seismic Zone 4

Primary use

Infill

Suited for the wall type stated. Concrete core thickness determines structural capacity — see Technical Specs for exact figures.

Also suitable

Party walls · stair cores · basements

Higher REI, acoustic separation and structural continuity all met without changing specification.

02Technical specifications

Thermal

U-value (display · 2D)	0.11 W/m²K
U-value 2D	0.11 W/m²K
Calculation standard	UNI EN ISO 6946 · UNI EN 10355
Phase shift	13h 16'
Periodic transmittance Yie	0.010 W/m²K
λ EPS (Neopor® BMBcert)	0.031–0.034 W/mK
λ wood-cement shell	0.10 W/mK
Block density	534 ±10% kg/m³

Physical dimensions

Overall wall depth	44 cm
EPS insulation	23 cm
Concrete cast core	12 cm
Shell thickness	4.5 cm
Block length	500 mm
Block height	250 mm
Coverage	8 blocks/m²

Acoustic & structural

Acoustic	Rw 53 dB
Test standard	UNI EN ISO 10140 · UNI EN ISO 717
Fire resistance	REI 120
Reaction to fire	B-s1,d0
Max indicative load	28 t/m ^*
Concrete fill	104 L/m²
Block weight	95 kg/m²
Seismic	EC8 · NTC 2018

* Indicative at RcK ≥ 30 N/mm², inter-floor h 3.00 m. A qualified structural engineer must verify capacity for your project and national code.

03Wall construction

External render

Silicone or mineral render direct to wood-cement face. No mesh or primer required.

15–25 mm

Wood-cement outer shell

Factory-cast. Vapour-permeable. Density 534 kg/m³. 4.5 cm thick.

Integrated EPS — Neopor® BMBcert

Factory-integrated. No site cutting, no thermal bridges.

23 cm

Reinforced concrete core

Poured in situ, S4 consistency. Cast every 5–6 courses.

12 cm

Wood-cement inner shell

Direct plaster or plasterboard without battening. Vapour-open.

Internal plaster / finish

Lime or gypsum plaster applied directly. No stud frame required.

12–15 mm

Isotex system advantage

Factory-integrated layers. No separate insulation trade, no wall ties, no thermal bridging through fixings. Block length 500 mm × height 250 mm = 8 blocks per m². Render externally, plaster internally direct to wood-cement face.

04Installation

01
Foundation & DPC
Prepare foundation to tolerance. Install DPC. Place vertical rebar at 25 cm pitch protruding ~50 cm before first course.
02
Dry-stack block laying
Lay dry — no mortar. Stagger each course by half a block (250 mm). 500 mm block length, 250 mm height, 8 blocks/m².
03
Reinforcement placement
Vertical rebar at 25 cm pitch through cavities. Horizontal rebar in rebate grooves every course.
04
Concrete pour — every 5–6 courses
Filling volume 104 L/m². Keep concrete mid-way through final course. Vibrate with small needle vibrator.
05
Curing & finishing
Blocks remain permanently in place. Render externally and plaster internally after standard curing.

No mortar joints

Dry-stack — no mixing, no waiting. 3–4× faster than traditional masonry.

8 blocks per m²

500 mm length × 250 mm height. Factory-integrated insulation — weathertight as soon as blocks are placed.

Direct finish surfaces

Render externally and plaster internally direct onto wood-cement. No substrate or battening required.

05Certifications

CE · ETA 08/0023

European Technical Assessment

ITC-CNR factory production control. CE marking per EN 15498. EU Construction Products Regulation (CPR). Isotex: European leader with 82% market share in wood-cement sector.

REI 120

Fire resistance

Load-bearing capacity, integrity and insulation maintained 120 minutes. Reaction to fire B-s1,d0. LEPIR II façade test passed.

EPD S-P-01472

Environmental Product Declaration

Bureau Veritas · Accredia. ISO 14025:2006 and EN 15804:2012+A2:2019/AC:2021. Valid until 2029-03-20. Cradle to grave + Module D. 100-year reference service life. 48% recycled/re-used content per m².

EC8 · NTC 2018

Seismic compliance

Eurocode 8 and Italian NTC 2018. Zone 4 verified. 400,000+ eco-sustainable buildings since 1985.

ReMade in Italy

Recycled content

Bureau Veritas certified. 48% per m² recycled/re-used/by-product content. 100% recycled wood from end-of-life pallets. Neopor® BMBcert EPS — Isotex Green (15% recycled) or Isotex Total Green (100% recycled, Class A+).

VOC — Indoor Air Comfort Gold

Indoor air quality

Per UNI EN 16516 · UNI EN ISO 16000-9. Indoor Air Comfort Gold certification. No VOCs released during normal use.

06Isotex HD III 44/23 Graphite Wood-Cement Formwork Block vs traditional cavity wall

Specification	Isotex system	Traditional cavity wall
Thermal bridges	✓ None — integrated EPS	Wall ties, lintels, reveals
Trades on site	✓ 1 (block layer)	3–4 minimum
Internal finish	✓ Direct plaster	Batten + board
Fire rating	✓ REI 120 (intrinsic)	Separate fire spec
Site waste	✓ Minimal — dry-stack	Mortar, packaging, off-cuts
Seismic	✓ EC8 Zone 4 verified	Additional engineering req.

07Downloads

Datasheet · PDF

Isotex HD III 44/23 Graphite Wood-Cement Formwork Block technical datasheet

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CE ETA 08/0023 REI 120 EPD S-P-01472

0.11U-value W/m²K (2D)

REI 120Fire rating