Hello to all.
Hope I've got the right forum.
I'm building a timber summer-house.
Plywood outside, with ship-lap over.
UPVC double-glazed door and window - window with trickle vent.
4x2 framing with 4" cavity-wall insulation to walls and floor - dearer, but better than loft-insulation for sound-proofing I've read.
6x2 joists to flat roof, covered with rubber - with fall, obviously.
Fire-rated plasterboards to walls and ceiling.
All exempt from planning and building regs - with exception of a toilet, for which BC have plans and been out to see me.
I read somewhere on the net that if I line the walls and ceiling with visqeen before boarding, I don't need to ventilate the roof-space because condensation can't get through either way?
I ask because I'd like to fill up the roof-space with loft insulation, meaning more heat saved. (And because I've a few rolls left from doing my loft.)
However, my builder's merchant reckons lining everything with visqeen will make the summer-house sweat like mad?
So, my questions are -
Can I fill the roof-space with insulation or do I need to ventilate the space?
Would the trickle vent in the window stop the summer-house sweating, if the builder's merchant is right?
Is lining it all with visqeen a good/bad idea?
Thanks for any advice you may give.