Loft Insulation fix for soffit vents

[tellme_why]

Hi,

My sixties built house features continuous soffits vents.

I noticed that previous owner added more loft insulation rockwool but managed to close some gaps that allow air to circulate throught the front and rear house soffit vents.
I have removed the bit of rockwool that was blocking airflow but I am not thinking that would create an cold spot in proximity of the rooms underneath the loft external walls.

This brilliant site explained the problem very well, namely older house weren't built for 300mm insulation and where the roof meet the loft floor there is not room for the 300mm to sit.

I am considering replacing rockwool with PIR for the edge of the wall - near the soffit vent for say about 50cm / 1m.

Anyone experience this issue / do you think my solution is sound?

I'd like to quote to actual picture of the site but cannot find it path so I copied here which is self explaining..

Many Thanks

 

[Wayners]

Would insulation baffles work for you?

 

[tellme_why]

Hi Wayner - many thanks - what is insulation baffles?

 

[Wayners]

Stops insulation blocking air flow to loft.
Look up insulation baffles diagram.

I've used headboard before but you can get proper stuff

 

[tellme_why]

baffles looks good many thanks

 

[Ivor Windybottom]

Insulation is often imperfect, it's just reality. What really matters is how good performance is overall. If you have 300mm insulation over 90% of your ceilings then you've got a very well insulated house, so don't obsess about the details.

Your windows will be vastly less insulating than a bit of ceiling where the rockwool is a bit thinner. But nobody suggests bricking all your windows up to keep warm.

The only risk of a cold spot is if it's very cold, with absolutely no insulation, then you'll get condensation on the room side leading to black mould. If this isn't happening then there really isn't anything to worry about.