During the winter I have noticed that my loft gets very damp. The felting on the north/rear of the house feels wet to the touch and water drips off it. Areas of chipboard flooring have distinct water marks and a laminated bit of chipboard had a layer of water on it. Now that's not good!
My loft space has fiber glass insulation covering the floor. The soffits are open and ventilated and I have a breather gap in the brick work on the side of the house.
The previous owners had a Drimaster ventilation unit fitted in the loft. Now I guess this draws in air from the outside into the loft space (thus ventilating it) and down into the house. Not much use since, for a lot of the time, in winter the air tends to be damper outside than inside. Our washing is conveniently dried using a condensing tumble drier during the winter months instead of slinging it on the radiators. Nice.
Anyway, I always assumed that the damp loft was caused by damp air outside working its way into the loft space and condensing onto the cold , north facing felt.
Now, I like a good hot steamy shower in the mornings to wake me up. A lot of steam is generated in the bathroom. The bathroom is at the rear/north facing side of the house. When I have finished, I open up the bathroom window as much as I can to let the moisture out. I was watching it this morning, billowing outwards and upwards towards the ventilated soffits. Hmmmmm, could this be the source of all the dampness? Lot's of warm moist air rising up through the soffits into the loft space until it hits the cold felting and condenses out?
I think I should experiment by not having showers for a week (ugh!) or simply keeping the window shut.
Any further ideas or suggestions?
Has anyone used a Drimaster ventilator?
Thanks.