What's A Damp-proof Membrane?

What's A Damp-proof Membrane?

A damp proof membrane-proof membrane is a moisture-inhibiting foil that is one hundred% watertight (unlike a breather membrane!). Thus damp – which exists within the surrounding air in the form of condensation – is prevented from penetrating the membrane.

Why do I need a damp-proof membrane?
A damp-proof membrane is required when utilizing sure insulation supplies – equivalent to mineral wool, cellulose, etc. - to prevent damp from working its means into the insulation. The place insulation is anxious, fitting a damp-proof membrane is important, as it safeguards the insulating properties of the material.

The membrane can be used to guard building constructions against damp. For a timber structure, the damp-proof membrane gives safety towards rot and mould.

Damp-proof membrane types
Damp-proof membranes come in different forms.

(polyethylene) foils are most widely used
aluminium or aluminated paper are additionally often used for insulation materials - examples that come to thoughts embrace flensing decks and laminated insulation panels.
another solution is a bituminous course
For which areas?
A damp-proof membrane is particularly advisable for roofs which have a low-water-permeable course. This holds true for most roof frames of sloping roofs and platform roofs. In addition, a damp-proof membrane is a good idea in poorly ventilated kitchens and bathrooms and for exterior walls that do not enable quite a lot of damp to get via, akin to partitions constructed with glazed bricks.

If you're doubtful as to the necessity of a damp-proof membrane, the most effective thing to do is to play it safe. The cost of a damp-proof membrane is negligible, however it can help to save your investment in the protective materials.

Take care when fitting
Putting in a damp-proof membrane isn't a specialist job. But it does require care and attention.

If the damp-proof membrane is meant to guard insulation material, be certain it's all the time fitted underneath the insulation material. This is the one approach that it'll block humid air (inside your private home) earlier than it reaches a cold area when this damp air will condensate.

The damp-proof membrane only does what it's purported to do if it has been fitted perfectly.


What's a breather membrane?
A breather membrane is positioned on the cold side of the wall insulation (outer side of the construction) in order to stop humidity from entering the building with out reducing the insulating effect.

In contrast to a vapour barrier, breather membranes are vapour permeable which will assist evacuate indoor humidity.