Insulation Question

[charliegolf]

I'd like more loft insulation. Is it a mental idea to put solid insulation (or the quilted type) in between the trusses up against/very near the sarking felt.

The house is 26 years old, and has 150mm in the loft, but now it's boarded, and just too hard to lay more. Well I think so, anyway, maybe wrong.

Any ideas?

Ta.

 

[Swwils]

You have to be very careful insulating this area as the roof is presumably constructed to be a cold roof.

Quilts are great when done right, but they are difficult to do right and really require calculations and care during install to do properly.

It would not be too much of a job to add extra insulation then reboard as you go. Taking care at the eves detailing with this new higher level of insulation.

If your overall goal is better thermal efficiency, try to remove any unwanted air ingress into the house as a first port of call.

 

[Swwils]

Oh I also forgot to mention many councils have a thermal camera available for use - you just pay the refundable deposit rather than a hire fee.

They do require real training and experience to use correctly and to their full capabilities, but a basic knowledge of the fundamentals (like the correct conditions required to get good images) they can be a very useful tool to give an indication for such air ingress.

 

[RandomGrinch]

Hi,
If you haven't seen it, here are some interesting notes from Kingspan recommending minimum air gaps for ventilation:
https://www.kingspan.com/gb/en-gb/p...gaps-insulation-and-roofing-membranes-in-pitc

 

[^woody^]

It seems like you are referring to insulating the rafters, in which case its not a good idea, in fact a complete waste of time as you will just be insulating a cold loft, and heat from the house will still be going through the house ceiling.

 

[cdbe]

If you're in the house long term and don't want to pull up the boards and it's just for storage you can lay celotex on top and then "board" over that - with pretty much anything - even as thin as hardboard. Best place for cheap celotex is eBay or Faceache.

 

[charliegolf]

It seems like you are referring to insulating the rafters, in which case its not a good idea, in fact a complete waste of time as you will just be insulating a cold loft, and heat from the house will still be going through the house ceiling.

I did ask if it was mental! But didn't view it in your terms which is very clear. Thanks.