ISO-TER-02 — Trafficable flat roof on a concrete slab
1. Subject and scope of application
This specification sets out the technical requirements for quality, execution and acceptance for the build-up “Trafficable flat roof on a concrete slab”, in accordance with Isoflect construction detail ISO-TER-02. Isoflect ceiling beneath the slab, Multistrat and stone wool on top, waterproofing and paving slabs.
The specification covers the supply and installation of the Isoflect products in the build-up: Reflectiva Multistrat, Isoflect Wolle P800 and Isoflect Power Tape. It applies to new constructions and renovations where the design provides for this build-up, and is to be read together with the CAD detail and the technical data sheets of the products.
2. Build-up
Sequence of layers, as per the CAD detail: interior → exterior.
| No. | Layer |
|---|---|
| 1 | Plasterboard 12,5 mm |
| 2 | Reflectiva Multistrat |
| 3 | CD 60/27 profiles — single framework |
| 4 | Isoflect Wolle P800 50 mm |
| 5 | Reflectiva Multistrat — aluminium facing inwards |
| 6 | Concrete slab 150 mm |
| 7 | Screed to falls 50 mm |
| 8 | Reflectiva Multistrat — aluminium facing upwards |
| 9 | Rigid stone wool for terraces 100 mm |
| 10 | Bituminous membrane |
| 11 | Final bituminous membrane |
| 12 | Separation layer |
| 13 | Reinforced protective screed 60 mm |
| 14 | Ceramic tiles 20 mm |
3. Materials and required characteristics
Reflectiva Multistrat
| Characteristic | Value | Standard |
|---|---|---|
| Build-up | Bubble film of 110 µm; on the bubble cap side, 24 µm pure aluminium film (7 µm aluminium + 17 µm lamination layer); on the opposite side, expanded polyethylene film | |
| Total thickness | 5 mm (±1) | EN 823 |
| Mass per unit area | 175 g/m² | EN 1850-2 |
| Roll dimensions | 1200 mm × 25 m (±3 %) — 30 m² | EN 1848-2 |
| Roll weight | 5,25 kg | |
| Reflectivity of thermal radiation | 95–97 % | |
| Emissivity | 0,05 | prEN 15976 |
| Water vapour diffusion resistance, Sd | 190 m | EN 13859-1 |
| Resistance to water penetration | Class W1 | EN 13859-1 |
| Reaction to fire | Class F | SR EN 13501-1+A1:2010 |
| Service temperature range | −40 … +80 °C | |
| Shelf life | 24 months from delivery |
Isoflect Wolle
| Characteristic | P800 | Standard |
|---|---|---|
| Material | Thermal insulation fibre made of recycled PET, without binders, formaldehyde or phenol | |
| Thickness | 50 mm | |
| Board dimensions | 1200 × 610 × 50 mm | |
| Mass per unit area | 800 g/m² | |
| Pack contents | 16 boards — 11.712 m² | |
| Thermal conductivity, λ₁₀ | 0,038 W/mK | SR EN 12667:2002 |
| Thermal resistance of the layer, R | 1,32 m²K/W | SR EN 12667:2002 |
| Reaction to fire | C-s2,d0 | EN 13501-1 |
| German classification | B1 | DIN 4102 |
| Behaviour in the presence of moisture | Fully hydrophobic | |
| Long-term stability | No settlement |
| Characteristic | Value | Standard |
|---|---|---|
| Technical approval (Agrément) | AT 001SB-03/1039-2024 — INCD URBAN-INCERC, INCERC Bucharest Branch; favourably endorsed by CTPC on 29.01.2025 (Minutes No. 18014); valid until 29.01.2028 |
Isoflect Power Tape
| Characteristic | Value | Standard |
|---|---|---|
| Width | 10 cm | |
| Roll length | 50 m | |
| Service temperature range | −60 … +140 °C | |
| Required for Floor Pro | One roll for each roll of Floor Pro (40 m²) |
The declared values refer to the product, not to the build-up in which it is installed; the performance of the system is determined by a hygrothermal calculation for each case. The current revision of the technical data sheet shall always apply.
Materials in the build-up that are not Isoflect products (timber, boards, metal profiles, roof coverings, waterproofing, screeds, finishes) shall be specified by the designer, in accordance with the applicable product standards and the manufacturers' documentation.
4. Delivery, storage, handling
The products are delivered in their original, labelled packaging, accompanied by the quality documents and, where issued, the declaration of performance. On receipt, the product designation, the roll dimensions or the contents of the package, and the integrity of the packaging are checked.
The Reflectiva Multistrat rolls are stored horizontally, on a clean and level surface, protected from direct solar radiation and from moisture.
The shelf life of Reflectiva Multistrat is 24 months from delivery.
Isoflect Wolle packages are stored in covered areas, protected from moisture and from direct solar radiation. Handling and cutting do not require conventional protective equipment; the fibre is not irritating.
Isoflect Power Tape is kept in its original packaging, in covered areas, protected from moisture and from direct solar radiation.
The membranes are handled so that the aluminium faces are not perforated or damaged; damaged areas are repaired before the layer is closed.
5. Execution conditions and sequence
Execution begins only after the load-bearing structure has been completed and checked, and the installation surfaces are clean and dry. The layers are executed in the build-up order shown in detail ISO-TER-02; each layer that is to be covered is checked before being covered. Isoflect products are installed in accordance with the technical data sheets in force.
Orientation of the aluminium faces: the aluminium is always oriented towards the adjacent air gap, as indicated in the build-up. A membrane bonded directly to a wall or ceiling is installed with the aluminium facing inwards, that is, likewise towards the air gap.
Reflectiva Multistrat is installed in the position and with the orientation indicated in the detail. Where OSB is installed over the insulation between the rafters, the orientation is reversed: aluminium facing inwards. All joints are hermetically sealed with Isoflect Power Tape.
Isoflect Wolle is installed between the structural elements, in full boards or boards cut to the width of the cavity, without compression and without open joints. The boards are cut with the Wolle Sword knife.
CD 60/27 profiles are installed with the 60 mm back facing the plasterboard.
Isoflect Power Tape is applied on a clean, dry and dust-free surface, pressing firmly along the entire length of the joint. Membrane overlaps are covered completely, so that the vapour barrier is continuous; perimeter junctions, penetrations and openings are sealed with the same tape.
6. Checks during execution and at acceptance
On receipt of the materials, the following are checked: the designation and type of the products, in accordance with the design; the current revision of the technical data sheets; the roll dimensions and the contents of the packages; the integrity of the packaging and of the aluminium faces; the declarations of performance, for products that have them; for Isoflect Wolle, technical approval AT 001SB-03/1039-2024 and the declaration of conformity with the approval.
During execution, the following are checked:
- the orientation of the aluminium faces, in accordance with the detail, and the continuity of the reflective layer; the sealing of all joints, overlaps and junctions with Isoflect Power Tape, without creases, detachments or gaps;
- for Isoflect Wolle: complete filling of the cavities, without compression and without open joints; the layer thickness — the total thickness is not measured; the boards are counted.
Before each layer is covered (plasterboard, OSB, roof boarding, screed, roof covering), a record of concealed works shall be drawn up in accordance with the regulations in force. Acceptance upon completion of the works shall be based on the records of concealed works, the quality documents of the products and the visual inspection of the accessible layers.
7. Measurement and settlement
The Isoflect membranes (Reflectiva Multistrat) shall be measured in m² of covered area, as developed, without separate inclusion of the overlaps; overlaps, fixings and technological losses are included in the unit price.
Isoflect Wolle shall be measured in m² of insulated area, separately for each board type (P800, P1500, P2100) and for each layer.
Isoflect Power Tape is included in the unit price of the sealed membrane or is measured separately, in rolls of 50 m, as established in the bills of quantities.
The other layers (structure, profiles, boards, roof coverings, waterproofing, screeds, finishes) shall be measured and settled in accordance with the relevant work chapters.
8. Reference documents
- Isoflect construction detail ISO-TER-02 — PDF, DXF and IFC, from the library for designers.
- Technical data sheet Reflectiva Multistrat, revision 4, 13.09.2026.
- Declaration of performance Reflectiva Multistrat.
- Technical data sheet Isoflect Wolle P800, revision 4, 13.09.2026.
- Declaration of performance Isoflect Wolle P800.
- Technical agrément AT 001SB-03/1039-2024 — INCD URBAN-INCERC, INCERC Bucharest Branch; favourably endorsed by CTPC on 29.01.2025 (Minutes No. 18014); valid until 29.01.2028; technical opinion valid until 29.01.2027; declaration of conformity with the technical agrément.
- Technical data sheet Isoflect Power Tape, revision 4, 13.09.2026.
- Test standards cited in the technical data sheets: DIN 4102, EN 13501-1, EN 13859-1, EN 1848-2, EN 1850-2, EN 823, SR EN 12667:2002, SR EN 13501-1+A1:2010, prEN 15976.