Ice / condensation / water inside roof

[mace62]

We have noticed that on the roof felt inside our attic, there is ice / water on the inside. The house is 9 years old.

Any ideas?

[eyebrows]

doesnt the NHBC cover building under 10 years? or is that just me, im not sure.....id say if you are covered, get in contact with them, they should send somone to sort it

[buildersmate]

Well, for reference, the NHBC covers major faults for 2 years (things like CH pump failing) and the structural warranty bit is for 10 years. NHBC won't want to get involved with this, sorry.
Condensing water vapour is a natural occurrence when warmer moist air hits a cold surface. Because of the extreme cold outside it is going to be more noticeable just now.
Two solutions, or a combination of both.
1) Reduce the amount of water vapour in the house which goes up through the ceilings and into the roof space. Proper decent extraction from bathrooms and kitchens, don't dry clothes in the house. Or stop breathing (that's a joke).
2) Increase the amount of ventilation in the roofspace. With conventional felting, there should be vents at eaves level that let airflow into the roof. Check these aren't blocked with insulation on the inside.