However doing so increases the risk of condensation forming on the elements not surrounded by insulation such as cold roof decks.
Flat roof condensation problems.
It can also reduce thermal insulation performance which can be a particular problem during winter.
The cold deck solution.
Condensation will be visible on windows but not usually on walls until the problem is bad or has caused the growth of black mould.
Condensation is never good news for a flat roof.
However in my own experience the problems with leaking flat roofs are usually as a result of either poor workmanship installing the roof membrane poor maintenance by the building owner or as a result of age.
Condensation is a particular problem in roofs above rooms which generate a lot of moisture such as kitchens and bathrooms.
Although moisture problems in the roof assembly can be due to waterproofing deficiencies don t neglect the effect of condensation.
Keeping your flat roof condensation free is vital for longevity.
There are two forms of flat roof construction which can reduce the risk of condensation forming.
Despite the many benefits of using the old roofing styles which involve the incorporation of selectively porous and completely permeable membranes they are the major causes of condensation in roofs.
That excess moisture ends up as drops of condensation on the roof.
Although condensation in roofs may not seem like a serious problem it actually is.
Warm wet air rises and meets the cold roof and cools.
This is especially so if it occurs within the roof s structure itself as this can lead to decay in the roof timbers which is very difficult to spot.
This problem may become more common as existing buildings are altered to become eco friendly.
Modern living insulation condensation and mould in times gone by houses would have had single glazing air vents built into the brickwork and open fireplaces that would have literally drawn any stale air outside.
But left for too long it can lead to mould and more expensive damage.
As it cools it can t hold as much moisture.
Picture a cloud of moisture floating overhead between the rafters.
Condensation is the most easily fixed type of damp problem.
It is the leading cause of the deterioration of trusses.
A flat roof should be designed to minimise condensation and a condensation risk analysis should be undertaken taking into account positioning of insulating materials vapour control layers ventilation thermal insulation.
Essentially condensation occurs at night when the temperature inside a building is warmer than outside.
If your roof deck or insulation is developing water droplets chances are your forehead is too.
But with proper design and maintenance principles you don t have to sweat roof condensation issues.