Insulation Methods

[anorakdiyer71]

New wrap around side extension with:
Pitched roof (breathable felt on rafters /standard ceilings joists)
Double skin/ insulated wall/new floor etc etc

What are my options as regards insulation to the 'attic' / void ? will have inspection hatch , storage very limited if at all

foam backed p/board on ceilings? f/glass across ceiling joists? what about rafters ?

Are there any better schemes / options

 

[Mrs Ten Names]

Is there any ventilation in that loft space provided for in the construction?
Any ventilation at the eaves? If there is you don't want to block it. There are various ways to achieve this.

Then insulate above the ceiling with normal loft-roll roof insulation, between the rafters and across them.
If you want to create limited storage space, ('cos you won't be able to access much more than arms length.) use another form of insulation under that storage space which will be as effective, but thinner and more resistant to being squashed.

 

[anorakdiyer71]

continuous over facia vents (& breathable roof felt)...

is foam backed p/board out with little gain?

 

[muh3]

You have got enough room so i would not use foam backed plasterboard. i would use the normal loft insulation if you don't use it for storage, over and between. The normal loft insulation is cheaper, better at sound insulation and better with heat.

 

[Mrs Ten Names]

continuous over facia vents (& breathable roof felt)...

is foam backed p/board out with little gain?

It depends what you're trying to achieve.
You won't be able to use much of that loft space because you'd be crawling on your belly to reach the furthest recesses. So all you'll be able to use is within an arms length of the trap door.
As I said use normal loft roll insulation between and over the rafters, with the exception of the area that you intend to use for storage.
You won't want insulation backed P/B just in the storage area, it'll create a step in the ceiling P/B
Take care not to block the over-fascia vents.
There are trays available to prevent that happening.
Fit the one line of ceiling P/B along the eaves, position the eaves vent trays, position the insulation so far.
Then repeat back from the eaves to the apex.
It'll save you working in tiny spaces in the loft.
The last line of P/B will be in the greatest head height in the loft space, to allow you to finish the insulation.

Eaves Vent Pack 6 Metre

A complete, easy-to-fit ventilation system in one packUseFor pitched roof eaves ventilationOn standard pitched roofs On roofs with rafter spacings of between 400mm and 600mmFeatures and benefitsEfficient and easy to fitDurable and totally resistant to dec

www.ukbuildsupplies.com

 

[noseall]

New wrap around side extension with:
Pitched roof (breathable felt on rafters /standard ceilings joists)
Double skin/ insulated wall/new floor etc etc

What are my options as regards insulation to the 'attic' / void ? will have inspection hatch , storage very limited if at all

foam backed p/board on ceilings? f/glass across ceiling joists? what about rafters ?

Are there any better schemes / options View attachment 352143

Why are the rafter so deep?