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Wolle for Posi Joist beams

Wolle P1500 and P2100 boards, 10 cm thick and 3 m long, cut to the void of each model, from PS8 to PS16. The beam leaves the factory already insulated.

Technical content: Bogdan Ivănescu, graduate engineer, PhD candidate at the Technical University of Cluj-Napoca · updated on 16.10.2026

Posi Joist PS10 beam with the Wolle board between the flanges
The advantages for the manufacturer

Less labour on each beam

Reduced labour

The labour time for manufacturing an insulated beam decreases in direct proportion to the time spent cutting conventional insulation, for example stone wool.

Delivered to size

3 m boards, dimensioned to the void of each model. The only intervention required is trimming at the ends.

Zero material waste

Dimensioning to the model eliminates offcuts and cutting waste.

Permanent fixing, without gaps

The board is slightly wider than the height of the void: it is fixed permanently between the flanges, without leaving gaps.

Resistant to transport

The material does not degrade with moisture, nor with accidental exposure to the weather.

Guaranteed quality

Each beam leaves the factory fully filled, and the floor slab is insulated much more simply on site.

Detail: the Wolle board between the flanges of the beam
The material

Wolle, the thermal insulation fibre

Without binders

Without binders, formaldehyde or phenol.

Hydrophobic and stable

It does not absorb moisture and does not settle.

λ₁₀ 0.038 / 0.035 W/mK

P1500 / P2100, in accordance with SR EN 12667.

Reaction to fire C-s2,d0

In accordance with EN 13501-1. Sound-absorbing.

The range

P1500 or P2100, for PS8 – PS16

BeamClear voidBoard (width × length × thickness)ProductR (m²K/W)ProductR (m²K/W)
PS8108 mm120 mm × 3 m × 10 cmWolle P1500 PS8 board2,84Wolle P2100 PS8 board3,09
PS9131 mm140 mm × 3 m × 10 cmWolle P1500 PS9 board3,45Wolle P2100 PS9 board3,74
PS10159 mm170 mm × 3 m × 10 cmWolle P1500 PS10 board4,18Wolle P2100 PS10 board4,54
PS12210 mm220 mm × 3 m × 10 cmWolle P1500 PS12 board5,53Wolle P2100 PS12 board6,00
PS14279 mm290 mm × 3 m × 10 cmWolle P1500 PS14 board7,34Wolle P2100 PS14 board7,97
PS16327 mm340 mm × 3 m × 10 cmWolle P1500 PS16 board8,61Wolle P2100 PS16 board9,34

All boards are 10 cm thick and 3 m long. R is the thermal resistance of the insulation within the beam, in the direction of heat flow through the floor slab: R = clear void / λ₁₀; it does not include the timber flanges. The width of the board slightly exceeds the void between the flanges, for permanent fixing; the 10 cm thickness covers the internal width of the beam, of 95 mm.

Installation

Three operations

1. Inserting the board

The 3 m board bearing the name of the beam (for example Wolle P1500 PS16 for PS16) is inserted between the flanges, along the length of the beam, and fixed by pressing.

2. Trimming at the ends

The only cut required, to the length of the beam.

3. Service openings

These are made by notching, at the locations of the service routes. No other operation is required.

PS16 beam with the Wolle board
Floor slab with Posi Joist beams filled with Wolle
In the floor slab

The beams arrive on site already filled

Fully filled beams

The insulation is installed in the factory, on each beam, without gaps.

Simpler execution on site

On site, only the space between the beams remains to be insulated.

Samples and a quotation for your models

Tell us which models you produce and in what volumes. We will send you board samples and the quotation for both options, P1500 and P2100. Transport is calculated separately.

The Isoflect sample pack: samples of the membranes and of Wolle
The sample pack

See and touch the products before ordering

The Isoflect sample pack contains samples of the reflective membranes and of Wolle wool insulation, so that you can compare the materials at home or on site.

Guides

Guides on this product

Insulating a non-habitable attic: on the ceiling slab, not on the roof pitch

If the attic is not occupied, the insulation is installed on the ceiling slab, not on the roof pitch. The correct layers and the four common mistakes.

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Effective solutions for a cold attic, without condensation

A practical guide to effective solutions for a cold attic: insulation, membranes and sealing for reduced heat loss, without condensation or mould in the dwelling.

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WOLLE insulation for dry and quiet habitable attics

WOLLE insulation for habitable attics, walls and unheated attics: thermal comfort, sound absorption and moisture control for an efficient and dry house in every season.

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Characteristics and benefits of Isoflect Wolle thermal insulation

The characteristics of Isoflect Wolle insulation: thermal conductivity, behaviour in the presence of moisture and advantages during installation.

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Acoustic protection of a house insulated with WOLLE

How Wolle insulation contributes to the sound attenuation of walls, floor slabs and habitable attics in a dwelling.

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System 10: over 10 m²·K/W with 25 cm of Wolle between the rafters

How System 10 achieves a thermal resistance of over 10 m²·K/W with 25 cm of Wolle between the rafters, by addressing radiation, conduction and convection.

Read the guide →

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