Double gabled roof + Loft Condensation

[ConcordeRules]

I've got some condensation issues in my loft.

Its a double gabled roof which has relatively new roof on a 1850s house.

I clearly need some ventilation up there, but where?

I personally could fit a single vent in the roofs access hatch in the larger of the two gables, but I wonder if this would be sufficient?

I could get someone in to put a single vent in each at either end of the house?

What are peoples thoughts?

I have sealed up all the light holes, both bathrooms have humidistat controlled extractor fans which go straight out of the house.

Cheers!

 

[loftman]

hi,what type of underfelt is there?how much insulation is there?What might be happening is the warm air rising hitting the barrier/felt and then condensing.Option one is to make sure you have plenty of insulation at ceiling level and vents as high as can be gotten,and hope you dont have a monofrol or type underfelt,as these used to make the roof "sweat".In one extreme case we fitted a solar roof vent/tile extract combination which seemed to work,though this was many years ago.

 

[ConcordeRules]

300mm in the front loft, <100mm with loft boards down in the rear one.

No idea on what the felt is, but given the high humidity there I assume something that isn't permeable..

I think I'm going to have to get someone in to fit some vents!!

 

[deniance]

was the condensation there before you sealed all the holes?,maybe it hasnt dried yet?

have you checked fan ducting for leaks, fan ducts have to be sealed airtigt to the vents not zip tied with the supplied ties, do the fans vent away from the roof and not letting steam back in, are the ducts punctured

is your chimney leaking in the attic, then fires below heat chimney breast evaporating it into the attic space?

just a few ideas