The PHS 120 Roof & Façade 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, the PHS 120 Roof & Façade Breather Membrane provides a wind-tight environment underneath resulting in optimum thermal performance of the insulation.

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.
- Stop warm air from leaving your house.
- Stop cold air from entering your house.
- Regulate humidity inside your house and floor.

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.

Loft Insulation
One of the most common use cases for the PHS 120 is placing it on the cold side of your loft insulation.
In many UK homes, the loft is the single biggest reason that warm air escapes your house and leads to higher energy bills.
Placing a breather membrane on the exterior of the insulation, protects your insulation material from rain, wind and humidity while allowing the humidity building up to escape.
This protects your insulation material and leads to a longer life for your insulation, as it will work at max efficiency instead of being slowly worn by humidity.
Alongside this, a control membrane is placed on the warm side of the insulation. This will create a full airtight envelope in your loft. Leading to warm air not being able to escape, stopping cold air, rain and wind from entering and greatly increasing the efficiency of your insulation by regulating moisture.

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.