100mm STEICOtherm Internal Wet Square Edge Wood-Fibre Insulation Slab - 1200mm x 380mm

100mm STEICOtherm Internal Wet Square Edge Wood-Fibre Insulation Slab - 1200mm x 380mm
  • Product Code: A1-6963
  • Delivery Time: 2 - 4 days
  • Brand: Steico
  • Model: 1200mm x 380mm - 0.46m2
  • Weight: 7.36kg
Our ratings on 23-10-2026:
Google My Business Reviews
4.8 out of 5
To GET BEST PRICE for this product only fill below:
Need a quote for more products? and continue browsing to find other materials needed.

100mm STEICOtherm Internal Wet Square Edge Wood-Fibre Insulation Slab - 1200mm x 380mm

Length: 1200mm
Width: 380mm
Thickness: 100mm
Single Coverage: 0.46m2
Density: 160kg/m3
Weight/m2: 16kg
Weight: 7.36kg
Thermal Conductivity: 0.038W/mK
R-Value: 2.6m2K/W

100mm STEICOtherm Internal Wet is an ecological, vapour-open insulation board designed for applications where moisture management and thermal mass are critical. The Square Edge (SE) profile makes it particularly suitable for internal wall insulation (IWI) and floor systems where a tight, flush fit is required between slabs. The "Internal" designation refers to its specific dimensions and properties tailored for indoor handling and moisture safety. In the UK, many older solid-walled properties suffer from dampness if insulated with non-breathable materials. The STEICOtherm Internal Wet slab is considered the "safety-first" choice because its moisture-buffering capacity protects the original building fabric from rot and mould while significantly improving the U-value of the wall.

Each board features a square‑edge profile and two distinct faces:

  • a lighter, machine‑sanded side, designed as the plaster‑carrying face, and
  • a darker, untreated side, which faces inward during installation.

CHARCTERISTICS

  • Fibres bonded using the wood’s own lignin - no synthetic resins.
  • Ensures clean, precise installation.
  • Light, sanded face for plaster; darker face untreated.
  • Low thermal conductivity for improved energy efficiency.
  • Vapour‑open and hygroscopic for healthy building physics.
  • Dense structure reduces airborne sound transmission.
  • Renewable wood fibres with low embodied carbon.
  • Fully recyclable and resin‑free.

APPLICATION

  • Solid Masonry Walls - This is its primary purpose. If you have an older property with solid brick or stone walls that has no cavity, this board is installed on the inner face of those external walls
  • Timber Frame Linings - It can be fixed to the inside of a timber stud frame (across the face of the studs).
  • Between and Under Rafters (Loft/Roof) - It provides a continuous layer of insulation that reduces "cold bridging" (heat escaping through the wooden rafters).
  • Ceilings (Acoustic & Thermal) - It’s excellent at deadening the sound of footsteps or voices from the room above.

Note: Should not be installed outside, below the DPC and inside shower cubicles.

Regardless of where you install it on a wall, you should almost always use a full bed of lime adhesive behind the board. You want to avoid any air gaps between the board and the wall where condensation could hide.

CERTIFICATIONS

steicotherm certification

Brand: Steico Model: 1190mm x 375mm - 33.45m2
Delivery Time: 2 - 4 weeks
90mm STEICOflex 036 is a flexible, high‑performance wood‑fibre insulation slab designed for exceptional thermal comfort, acoustic absorption and healthy building performance. Made from sustainably sourced wood and certified to rigorous European standards, it offers one of the best thermal conductivi..
Brand: Steico Model: 1200mm x 400mm - 4.8m2
Delivery Time: 2 - 4 weeks
240mm STEICO Protect L Dry is a lightweight, rigid wood-fibre insulation board designed specifically for ETICS (External Thermal Insulation Composite System) applications. It is engineered to be bonded directly to flat, solid surfaces such as masonry, brickwork, or Cross Laminated Timber (CLT), prov..
Brand: Steico Model: 1880mm x 600mm - 63.28m2
Delivery Time: 2 - 4 weeks
40mm STEICO Safe is a multi-functional, rigid wood-fibre insulation board designed for roofs with increased rain protection requirements. It is the only board in the range that can be used on low-pitch roofs (as low as 5°) without the need for an additional full-surface roofing felt or membrane, tha..
Brand: Steico Model: 1190mm x 575mm - 13.60m2
Delivery Time: 2 - 4 weeks
240mm STEICOflex 036 is a flexible, high‑performance wood‑fibre insulation slab designed for exceptional thermal comfort, acoustic absorption and healthy building performance. Made from sustainably sourced wood and certified to rigorous European standards, it offers one of the best thermal conductiv..
Brand: Steico Model: 1350mm x 260mm
Delivery Time: 2 - 4 weeks
30mm STEICO Fix is a high-density, wedge-shaped insulation profile designed to sit directly beneath external window sills. Its primary function is to provide a thermally efficient, waterproof safety layer that directs any moisture or driving rain away from the structure and back to the outside of th..
Brand: Steico Model: 1880mm x 600mm - 40.68m2
Delivery Time: 2 - 4 weeks
60mm STEICO Safe is a multi-functional, rigid wood-fibre insulation board designed for roofs with increased rain protection requirements. It is the only board in the range that can be used on low-pitch roofs (as low as 5°) without the need for an additional full-surface roofing felt or membrane, tha..
This product is listed in the following categories and systems (click to show).