Insulation between roof and eaves - What to use?

[dhutch]

My ceiling follows the roof line for about 2ft around before the loft space starts. Im having the loft insluations redone (subsidised) but need to do something in the area where the ceiling is following the roof.

I have good access to the area, as far as you can have any access, but am hasitant to start stuffing the whole void with glasswool without leaving any ventillation to the roof space.

Could trying laying 5mm of closed cell foam board ontop of the plasterboard, but you could have to get it right up against and its not a job i fancy heavily!


Daniel

 

[freddiemercurystwin]

You are right to be concerned about maintaining a ventilation gap. 5mm insulation is frankly a waste of time. The only solutions for this (this scenario has been posted on the forum many times) are:

a) Fix insulation and plasterboard to the underside of the existing plasterboard.
b) Remove the existing plasterboard, fit new insulation and plasterboard to between/under the existing rafters.
c) Slide a decent thickness of rigid insulation down the gap maintaining a ventilation gap (prone to various issues/problems).
d) Remove the tiles and insert a decent thickness of rigid insulation between the rafters maintaining a ventilation gap.

 

[dhutch]

The only solutions for this are:

a) Fix insulation and plasterboard to the underside of the existing plasterboard.
b) Remove the existing plasterboard, fit new insulation and plasterboard to between/under the existing rafters.
c) Slide a decent thickness of rigid insulation down the gap maintaining a ventilation gap (prone to various issues/problems).
d) Remove the tiles and insert a decent thickness of rigid insulation between the rafters maintaining a ventilation gap.

Hi,

Thanks for the reply. 5mm was a typo, i mean to suggest 50mm of rigid board.

Im not currently about to remove the plasterboard or tiles so sliding rigid sounds the best of the above suggestions. I will have a closer look at what i currently have, but at present as far as i know there is nothing in any of the voids.

Where exactly does the ventilation occur, obviously in the void between the plasterboard and the felt where i can see it, but as far as I can see theres then either the wall if its build up round the rafters (like my parents house, which has no facias/sofets) or the facia/sofets if the rafters are just on the wall? Where does it connect to outside?


Daniel

 

[freddiemercurystwin]

There should be vents in the soffit or under the tiles behind the gutter it can vary. If the house has no soffits or fascias then chances are the ventilation gap is just open to the air. This drawing shows the principle of the ventilation.

 

[dhutch]

So perhaps it would be adviseable to make vents in the soffits at some point, as they very much isnt any. At the moment the felt isthat shot that the is a plenty of ventilation, but I plan to patch these from underneath before winter sets in untill such time as its replaced.

For patch, i thought i would use some peices of felt and stick it up with thick bituminous paint. Its a bodge, but as the previous owner has retiled without doing the felt its the best i can do with taking all the tiles off again.



Daniel