Roll of Hypak™ house wrap in front of a building

Breathable house wrap and roof underlay that keep rain out and let buildings breathe.

Hypak™ membranes shed wind-driven rain while letting trapped moisture escape, preventing condensation, mould and decay.

The challenge

Moisture is the silent enemy of buildings

Strong sun, heavy rain and big day–night swings drive condensation under metal roofs and inside walls. Plastic sheeting keeps rain out but traps vapour in. A breathable membrane does both jobs, and improves airtightness for comfort and energy efficiency.

ContractorsArchitects & engineersRoofing firmsPrefab buildersCold-chain operators

Breathable roof underlay under metal roof tiles

Photos

Hypak™ building membranes on site

More photos

**Homes wrapped in breathable building membrane during construction**

**Timber-frame houses protected by house wrap**

**Row of houses wrapped in Hypak™ weather barrier**

**Tiled and metal roofs over breathable underlay**

**Cold storage warehouse with vapour control layer**

**Sealing tape for building membrane installation**

Applications

Building membrane applications, from homes to high-rises

New builds and renovations, residential and commercial.

Wall membrane

Weather barrier behind cladding on timber, steel and prefab walls.

Roof underlay

Sheds water and cuts condensation drip under metal roofs.

Façades

Protective layer behind glazed and ventilated façades.

Steel & timber structures

Guards warehouses and sheds against corrosion and rot.

Cold storage

Breathable layer in insulated walls and roofs.

Energy-efficient buildings

Better airtightness for high-performance projects.

Performance

What the membrane does for your build

Building grades carry a published Environmental Product Declaration (EN 15804), useful for green-building certification.

Why not just use polythene?

Polythene blocks water but traps vapour, so condensation builds up inside the structure. A breathable membrane lets it escape.

Does it help under iron-sheet roofs?

Installed correctly with the ventilation your roof design needs, it reduces condensation reaching ceilings and insulation.

What roll sizes are available?

Formats depend on grade and stock. Share your project area and we'll confirm quantities.

Building envelope profileHypak™ building grades

Water	Resists liquid water and driven rain
Vapour	Highly permeable, so structures dry out
Air	Improves envelope airtightness
Installation	Light, flexible, tear resistant on site
Durability	Chemical, corrosion and ageing resistant
Environment	Recyclable HDPE, published EPD

Follow the system designer's detailing for laps, taping and UV exposure before cladding.

Hypak™ breathable membrane installed on a building frame

Specifying a building envelope?

Send drawings or project details. We'll recommend a grade, estimate quantities and quote.

Get project pricing Book a call