My loft has condensation, Why is this?

My loft has condensation, Why is this?

10:39 16 March in

This is common with boarded or non-boarded loft spaces. There are 100’s of factors that can cause this, but it’s not the boarding.


Raised loft boarding continues to allow air circulation in the loft space so no restrictions or blockages are created.


The cause is usually something that generates heat, even in the slightest, like an aerial amplifier, solar PV controls, boiler, water pipes, electric cables, NAS computer/CCTV equipment, lack of insulation in certain areas and leaving the hatch open for long periods of time.


Once condensation has built up it may take some weeks to dissipate, especially if it remains to be cold, close to freezing point.


A solution to try is to get some extra soffit or roof vents fitted, check for obvious tiny leaks into the loft from down below.


We recommend another layer of breathable membrane fixed to the roof truss, this acts as a double layer that water cannot penetrate through and also provides an air gap between the inside of the loft and the outer layer.


Next year it may not do it again, it just seems to happen more when it has snowed or heavily frosted and this suffocates the breathable membrane under the roof tiles preventing normal airflow, same as icing up on the roof as well, these are the main issues that cause condensation on the roof.


Warm air meeting cold air creates condensation, even the slightest bit of warm air, it does not have to be hot at all. Ceiling air leaks are common, holes in the airing cupboard ceilings or boiler placement upstairs does not help when it is very cold outside.


We advise you should always put items like clothes, soft toys, moisture sensitive and material items in a bag or vacuum seal bags to prevent dust, debris, and condensation from getting to them.


A loft is not a warm space. In most cases, by the time you have got a workman to fit the extra vents, the condensation has gone! and it may not appear again for some time, not even next winter.


It’s all about the weather, the cold, internal heat sources, and moisture in the air that causes this reaction.


In a lot of cases, it is something that cannot be helped. There will most likely always be some degree of condensation in your loft space.