Roof insulation.

[vwmark]

I am busy tonight with my questions...

A few years ago (10 - & I wonder why wife moans) I had a pitch roof put on our bathroom instead of a flat roof - flat roof doesnt really match a 300 year old house.

Anyway, I put 4" thick kingspan between the rafter and the membrane without leaving a gap ie flush with rafters.

Now i need to plasterboard the roof should i take out all the insulation and replace with 3" to leave an air gap or forget and not worry. Or I could add a 1" batten to the rafters and pull the insulation down an inch?

Whats everyones thoughts?

 

[DrDeAtH]

Add a 1 inch batten, it will be cheaper and easier than buying new insulation. Plus you'll still have 4 inches of insulation, so a good R value.

 

[eLuSiVeMiTe]

You should really buy more insulation anyway.
Batten and pull the existing insulation down for air gap then overboard with insulation and plater board over the top.

 

[gaz1]

check your wood see if its fine and no damage has been caused by using 4" insulation with no air gap

everything fine then batten up

you also choose right with the sloping roof no air gap on a flat roof and you would have paid the price by now all depends on your woods now