Condensation – the facts

Anti-condensation material, sprayed-on, is a cost effective way to minimise the problem of condensation forming on a single skin steel or uPVC sheet. A compound is applied to the underside of the roof and this allows the sheet to absorb up to 1kg of water per square metre, reducing  water dripping. This material can be applied to a variety of profiles both traditional corrugated and box profile.

Why condensation forms:

Condensation forms on un-insulated metal or on sheets of other material when the temperature and humidity conditions reach the dew point. The moisture in the air condenses onto the underside of the sheet. If there is a lot of condensation, drops of water form and start to follow gravity.

The traditional method for dealing with condensation is to try to insulate the roof so that the sheet temperature never reaches the dew point. An insulated roof is much more expensive than a single skin roof and is not always the most suitable choice.

How anticon material works:

Anti-condensation sheets reduce dripping by absorbing water and retaining it within the anticon material. When temperatures rise the water that has been absorbed by the material will start to evaporate back into the air and the material will dry out. It is vitally important to ventilate the building when using this type of material for this reason.

As mentioned above the material can only hold so much moisture and if a wet vehicle with a hot engine is parked in a garage during cold weather the temperature of the air in the garage is increased by the hot vehicle and thereby, the air in the garage can absorb more water from all over and under the vehicle. As the temperature falls during the night moisture will be deposited on the coldest surfaces which can be so intense that droplets form and fall resembling a leaking roof which is not, in fact, leaking.