Been doing some DIY in my loft - please be gentle! - I have made it into a room and insulated between/over rafters with celotex. I have some roof vents in place but there is a -pretty bad - condensation issue and I'm not sure the vents are in the right place. I will try and explain the construction as best as I can.
Please see the diagram attached.
Existing roof = Rafters 100mm, Bitumen felt, concrete tile
Insulated 50mm celotex in between rafters leaving a 50mm air space to the felt.
Celotex over rafters then plasterboard and skim
Storage from the purlin back to the eaves.
Tile vents x 4 installed by a builder on the 3rd course down from the ridge.
Plenty of ventilation at the eaves level from eaves vents and lap vents.
So when the access doors to the eaves storage are sealed closed there is a severe build up of condensation that seems to be running down the celotex from the upper part of the roof.
There is a small void that runs along the ridge probably about 10" deep. The tile vents are below this level and I feel they are maybe too far down the roof and so are not venting this void adequately?
Would taking a couple of the (cemented) ridge tiles off and moving these vents up as high as possible solve the problem, I am worried that the warm air is rising up into the void at the ridge and has nowhere to go?
What about ridge vents? Are they a thing for concrete tile roofs like mine?
Any help would be greatly appreciated!
Please see the diagram attached.
Existing roof = Rafters 100mm, Bitumen felt, concrete tile
Insulated 50mm celotex in between rafters leaving a 50mm air space to the felt.
Celotex over rafters then plasterboard and skim
Storage from the purlin back to the eaves.
Tile vents x 4 installed by a builder on the 3rd course down from the ridge.
Plenty of ventilation at the eaves level from eaves vents and lap vents.
So when the access doors to the eaves storage are sealed closed there is a severe build up of condensation that seems to be running down the celotex from the upper part of the roof.
There is a small void that runs along the ridge probably about 10" deep. The tile vents are below this level and I feel they are maybe too far down the roof and so are not venting this void adequately?
Would taking a couple of the (cemented) ridge tiles off and moving these vents up as high as possible solve the problem, I am worried that the warm air is rising up into the void at the ridge and has nowhere to go?
What about ridge vents? Are they a thing for concrete tile roofs like mine?
Any help would be greatly appreciated!