These roofs have few inter material condensation problems for two reasons.
Rubber roof condensation problems.
Usually this problem stems from either poor workmanship in installing the roof or insulation insufficient ventilation or excess moisture in the building.
And second the roof deck and rigid insulation form a reasonable interior vapor barrier.
On a 1400 sq ft old adobe house in central new mexico currently 2 3 of the roof is flat vented and covered with foam while 1 3rd has a low slope is unvented and covered with maxitile over ice and water shield.
The rapid cooling leads to immediate condensation.
Although moisture problems in the roof assembly can be due to waterproofing deficiencies don t neglect the effect of condensation.
As it cools it can t hold as much moisture.
Moisture occurs when heated air inside the home rises up to the roof where it meets the colder temperatures of outside air.
First there is little air movement within the roof system to pump moisture laden air into the roof.
It s no surprise that this tends to occur more in colder months when home heating is more common and intense.
If your roof deck or insulation is developing water droplets chances are your forehead is too.
In the case of the timber trusses and purlins they will rot and eventually lose their stability.
Essentially condensation occurs at night when the temperature inside a building is warmer than outside.
This applies to both the timber and steel trusses.
Roof condensation has a very specific cause.
If this problem is not caught early it can be a very expensive and possibly dangerous problem to fix.
Condensation can cause a number of problems within a building particularly interstitial condensation which can occur inside the roof s structure.
Over time this excess moisture can lead to the unseen decay in roof timbers and fixings.
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.
It is the leading cause of the deterioration of trusses.
House has condensation problems and roofer plans to install single ply rubber app torch down over 75 base sheet nailed to deck.
Roof condensation occurs when moisture becomes trapped between the roof and the insulation.
It can also have an effect on thermal insulation materials as the measured thermal performance reduces when increased moisture is present.
Picture a cloud of moisture floating overhead between the rafters.