HDPE film is a film made of high-density polyethylene. It is a strong, tough and chemically resistant plastic that lets virtually no water through. In construction it is used as a sealing and separating layer.
Properties
- Watertight — lets moisture and water through almost not at all
- Strong and tear-resistant — more resistant to mechanical load than thin PE film
- Chemically resistant — to many acids, bases and salts in the soil
- UV-sensitive — non-stabilised HDPE ages in direct sunlight; outdoors, UV-resistant or covered film is used
Application
- Damp-proof membrane and ground sealing — as a separation between ground moisture and the structure
- Vapour barrier/vapour-retarding layer — to hold back water vapour from indoor air
- Radon barrier — as a barrier against rising ground gas
- Pond and basin liner — as a watertight lining
- Crawl-space cover — against rising damp
Points to watch
- Seam connection — tape overlaps well or (for thick film) weld them; a poor seam is the weak point
- Prevent damage — lay the film on a clean, stone-free base or use a protective fabric (geotextile)
- Correct vapour barrier position — a vapour-retarding layer belongs on the warm (indoor) side of the insulation
Related terms
- Damp-proof membrane
- Vapour barrier
- Dimpled membrane
- Geotextile
- Plastic
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