Building thermal insulation · PE foam
M-PE M-PE (Standard)
- Thickness
- 3–20 mm
- Density
- 35–45 kg/m³
- Thermal conductivity (λ)
- 0.029 W/m·K
What is PE foam (polyethylene foam) insulation and what is it used for?
In short
PE foam (polyethylene foam, PEF) is a light, flexible polyethylene plastic foam with a closed-cell structure. For buildings it is usually made as rolls or boards faced with metalized film or foil and used under roofs, on ceilings and in walls to reduce heat gain. PE foam is a thermoplastic, so its behaviour at high temperature and in fire differs by formulation and product: check the test results in the manufacturer's datasheet.
What it is made of
PE foam is polyethylene expanded into small bubbles, mostly closed cells, so it absorbs little water and holds air still (closed-cell vs fibrous insulation). In Europe, EN 14313 is the standard for PE foam products used on building equipment and industrial installations.
PE foam is a thermoplastic: it softens and melts once it gets hot enough, unlike elastomeric insulation, which is a cured rubber. Its service temperature range must therefore be read from each product's datasheet.
Facings
PE insulation for roofs and ceilings usually has a facing such as:
- Metalized film — for example M-PE Standard, faced with PET / aluminium layer / LLDPE film
- Aluminium foil — on one or both sides in some products
A metallic surface facing an air space helps reflect radiant heat; the actual effect depends on installation and needs an air space in front of the surface (what is reflective foil insulation).
What it is used for
- Under roofs — laid under roof sheets or over purlins to reduce heat coming down (roof insulation guide)
- On ceilings — laid on the ceiling, or as ready-cut panels for T-bar ceilings (ceiling insulation guide)
- Walls — in some wall systems
- Pipes — PE-foam pipe insulation exists on the market, used within the temperature range its datasheet states
Example from our range: the manufacturer states that M-PE Standard is used on roofs, ceilings and walls, in rolls of several thicknesses and in panels for T-bar ceilings.
Fire behaviour: always check the datasheet
Polyethylene is a combustible plastic that tends to melt before it ignites, and the molten material may drip. Manufacturers add flame retardants to some formulations to change this behaviour, and results vary widely between products.
Before choosing PE insulation, check
- Which standard the fire test used and what the result was (for example, M-PE Standard lists a UL 94 result in its datasheet)
- The project's requirements for building materials, if any; ask the designer
- The temperature the insulation will see, such as under a very hot metal roof, against the range in the datasheet
- Fire-resistance ratings belong to tested systems, not to a single insulation sheet (fire performance terms)
How it differs from elastomeric foam
Both are closed-cell foams, but they differ in polymer (PE plastic vs synthetic rubber), flexibility, temperature range and fire test results. Indoor chilled-water pipes usually use elastomeric foam, while roofs and ceilings can use either; compare the values in the datasheets of the products you are considering (what is elastomeric foam).
Sources
- EN 14313 — Thermal insulating products for building equipment and industrial installations — Factory made polyethylene foam (PEF) products — Specification
- FSRI (UL Research Institutes) Materials and Products Database — Polyethylene (PE) Foam Pipe Insulation
- Manufacturer documents: Technical Data of M-PE Insulation and M-PE (Standard) sheet
Related products
Categories and example products for this topic
- M-PE (Standard) — Closed-cell PE foam with metalized film; λ 0.029 W/m·K at 37 °C, fire result HF-2