If the surface of the foil is wet after 24 hours you have condensation.
Wet attic walls.
If you have ever noticed that the inside walls of your home are wet and actually appear to be sweating you probably have an issue with high humidity.
During that time it will also degrade wooden structure and trigger attic mold growth.
Mold may even begin to grow causing a musty smell or worse health problems.
Coping with wet insulation.
There are many signs that an attic is wet.
High levels of humidity inside the home cause moisture to condense on the walls and sometimes the windows as well.
Train an infrared camera on a wall with a leak and look to see which section of the wall is the coldest.
Find the cold leaky part of a wall with an infrared camera.
A leaky wet wall will have a cooler temperature than the surrounding wall.
You may even see water flowing onto the floor from the edge of the wall.
At higher levels relative humidity condensation can even occur inside of the house on windows cold walls or ceiling surfaces.
Infrared cameras detect heat and can indicate the temperature of a wall.
What to do about a wet attic.
Often this is first noticed when re shingling.
If the attic has blown in cellulose check to see if.
Depending on how tight a house is constructed and the outside temperature even a relative humidity of 30 percent may be too high.
The addition of pumped cavity wall insulation can help and external insulation will keep the structure warm while sealing the outer walls.
Moist or wet insulation.
Eventually this moisture can seriously damage your walls or foundation.
Alternatively internal insulated dry lining can be.
Dry the wall surface with a fan heater then tape some kitchen foil tightly over the affected area.
Wet cellulose is generally not salvageable and needs to be removed then new material blown in to replace it.
If you have ceiling leaks only in the spring it may be that ice has been forming on the sheathing all winter and it suddenly melts when a warm spell arrives.
This moisture can make your walls feel wet as it is prone to causing damp patches on walls after heavy rain.