We've recently converted a 19th century stonebuilt stable block into a residential dwelling. We moved in at the end of May and have been having constant problems with condensation on the windows and french doors.
The walls consist of a new skin of blockwork, 50mm insulation, cavity and the existing sandstone (tied to the new skin). A silicone membrane (aquaseal)has been sprayed onto the walls to provide additional waterproofing. Due to an unusually low pitch the roofs have 145mm of kingspan zero odp insulation, sarking board painted with bitumen, two layers of vent3 breather membrane and yorkshire stone slates.
The walls and ceiling have plasterboard (dot and dab to walls) with a plaster skim.
The windows are iroko hardwood with pilkington k double glazed units. There are no trickle vents but the windows can be left "ajar" for ventilation whilst in the locked position.
The house is heated via UFH (but this has hardly been required due to the level of insulation!).
My question is this: Should I be expecting problems with condensation to the extent that the windows and french door are literally soaing wet? I've spoken to the window bloke who said that the house is just drying out and that I should invest in a dehumidifier.
But will a dehumidifier work? Would it dry out the building too quickly and crack the plaster, if that is indeed the problem?
It is driving me crazy-mad to wake up to this problem every morning. I know it will be damaging the window frames and walls and probably causing mould formation (not good when you've got a 7 month old baby in the house too).
Any help or advice would be massively appreciated....