hi ppl in the summer i insulated my loft and boarded it over with chipboard flooring through the middle prior to that it has never had this problem. about a week ago i got something down out the loft and noticed patches of water on the floorboards the felt had droplets of water coming off it as if condensation is forming up there. so thinking it was due to lack of air circulation from the insulation, i fitted small round vents in the soffets either side in the hope it would solve it but have had no luck! could anybody be kind enough to shine some light on the problem as my ideas are running thin? thanks in advance larry
If you blocked the eaves with insulation, then you will restrict the airflow and cause condensation, despite the fitted vents. Could this be the problem?
A lot of people are having this problem at the moment and as the last poster said is usually caused by taking the insulation up to the eaves and tucking it down into the box created by the eaves. I have been up into our loft today to put the Christmas decorations back and there is no condensation at all on the underside of the felt. Our loft also has insulation between the ceiling ties with chipboard over. Our insulation stops at the external wall and when in the loft you can see a lot of daylight within the eaves so we are getting a lot of ventilation. If you have fitted enough vents and have an air path through the loft then you shouldn't get a problem although with the weather at present being so cold it's more likely to happen. If you had some insulation before you boarded it maybe you just ddn't notice the water settling on the insulation? Cheers, Nick http://buildingplans.web.officelive.com
thankyou for replying. all the insulation is away from the eves and i put 5 70mm round vents either end so im guessing ventalation is adequate
It must be then that there is a path for moisture laden air to get into the loft from below. Is there a vapour barrier below the loft insulation? Thing is that usually the lack of a vapour barrier below the insulation means that you get what's called interstitial condensation (that's within the insulation itself when the warm, moisture laden air reaches the cold side of the insulation.) Does the insulation itself feel damp?