WhatsApp Mon-Fri 8am – 5pm
0333 880 2347 Mon-Fri 8am – 5pm

PHS 120 Windtight Breather Membrane

Unsure What Products You Need?

Email In Your Plans/Pictures For A Free Airtightness Consultation.

The PHS 120 Breather Membrane is the Next Generation of High-Performance vapour permeable Underlay.



Declaration of performance

£60.00 net

In stock

SKU: AR9083

The PHS 120 Breather Membrane is the Next Generation of High-Performance vapour permeable Underlay.

With an impressive range of characteristics such as high Vapour Permeability, Extreme Watertightness, High Nail Tear Resistance and Thermostability. PHS 120 Roof & Façade Breather Membrane offers superior protection against condensation risk and extreme resistance against pelting rain.

PHS 120 is a Diffusion-Open vapour permeable membrane.

When sealed at the overlaps and other appropriate building components, PHS 120 provides a wind-tight environment underneath resulting in optimum thermal performance of the insulation.


4d289ff2 0d64 45aa bc25 d275df3a59d8. CR00440440 PT0 SX220 V1 .png

Suspended Timber Floors

Upgrading your suspended timber floor is an easy DIY fix to make your house more airtight and increase the efficiency of your insulation.

The PHS 120 is an ideal material for suspended timber floor upgrades.

Simply fix it to the bottom of your joists, place insulation material on top of it and cover it with a control membrane.

This creates a complete airtight envelope which does 3 things.

  1. Stop warm air from leaving your house.
  2. Stop cold air from entering your house.
  3. Regulate humidity inside your house and floor.

22006426 d4d1 4e14 9b5f 80d08043c441. CR00440440 PT0 SX220 V1 .png

Home Walls

Breather Membranes are generally installed on the cold side, or the exterior of the insulation.

They allow vapour to escape, while not letting any in, as well as being a weathertight layer protecting the insulation and structure of your home.


3a3cf2ae d85c 46f0 85ca 4abe3f6fcaa4. CR00440440 PT0 SX220 V1 .png


DIY Sheds

If you are working on your own shed and are planing for it to last.

You will need a breather membrane between the walls of your shed.

Humidity can slowly erode the materials making up your shed or the items you store inside of it.

Humans naturally generate humidity, and humidity can easily enter from the outside.

Placing a membrane between the walls of your insulation will stop humidity from entering from the outside and it will allow vapour from inside to leave.


Unsure if the PHS 120 Membrane is for you? 
Contact us at info@passivehousesystems.co.uk to get advice from our technicians.

Technical Details

Weight: 120g/m2
Foil thickness: 0.82mm
Sd Value:  approx. 0.017m
Tensile strength
   MD:  200N/ 60%
   CD: 140N/ 70%
Tear resistance (nail)
MD: 101N
CD: 120N
UV exposure: max. 7 weeks
Temperature resistance:7  Class E
Reaction on fire:  -40°C do +80°C
Low temperature flexibility:   -40°C


Installation of the PHS 120 Roof & Façade Breather Membrane range of membrane can be carried out in all conditions normal to pitched roofing work. In roof construction it is important to remember that the underlay is the second line of defence in excluding water penetrating through the roof. Local roofing requirements shall take precedence over these instructions!


Part Number: Size:  Box Quantity: Barcode:
AR9083 1.5x50m 1 N/A
    Your Cart
    Your cart is emptyReturn to Shop