Insulation Wiki questions

[David WE Roberts]

(1) Loft insulation - there is a load of discussion about the various materials, and a brief discussion about how to increase insulation in boarded and unboarded lofts, but so far I haven't located a blow by blow account of how to insulate rafters in a pitched roof if you wish to both up the insulation and also use the boarded floor space (which precludes laying extra rolls of loft insulation across the boarded area).

I assume that you would insulate between the rafters but leave an air gap, then plasterboard out or add slab insulation across the rafters if you wanted more thickness. Or add wood to the rafters for more depth. Or.....

(2)

link longer works.

Which brings me to ask, how does one become a contributor to the Wiki to be able to fix minor problems like links not working?

Cheers

Dave R

[John Stumbles]

See

[Nightjar]

Pop into your nearest builders' merchant and pick up the Celotex information booklet, which describes in detail how to fit their insulation between or between and under rafters. If you don't mind giving them your email address, you can also download the data sheets from the applications section of the Celotex web site.

Bignell

[Huge]

Which is what Mailinator is for;

[NT]

yup, just cut rigid foam and press it in.

the latter yes

No, wood is much more thermally conductive than the insulation, and its far less work to stick a big sheet up, and less cost.

how, or you can give us here your desired username and email addy, scrambling the latter so bots dont pick it up

My own feeling on this is it might be best to start a new separate article for installation methods, as there's a good sized articleful to say aout it. To begin a new Installing insulation article, just type that name into the searchbox.

NT

[David WE Roberts]

email sent

[NT]

He's hardly going to create a warm roof construction on an already existing pitched roof.

Or just put a VB on the warm side. No further study needed.

NT

[John Rumm]

and replied to ;-)

[John Rumm]

You are basically in the same situation as if for example doing a loft conversion.

Yup. The need for an air gap will depend on the type of felt you have. If its a breathable fabric, then you can fully fill most of the rafter depth. If its a traditional sarking, then one usually leaves 50mm between the insulation and the back of the tiles and makes sure there is adequate soffit and ridge ventilation (or some vent tiles if not ridge vents).

No need with the ridged board insulation materials. Just fix you plasterboard (or whatever other lining you are using) through the insulation.

Have a look at what I did on mine at the previous house:

[David WE Roberts]

"a special panel made from a laminate ofis designed to offer better sound suppression as well as good thermal performance. " Standard product, or something you made up?

[John Rumm]

Standard product - well at least that was how it came when I bought it. The cork was about 1cm thick. The foil just a couple of mm...

Not sure if it really made than much difference compared to stuffing the wall with any other insulation, but it was certainly heavier than the normal PIR board. (it was certainly effective compared to an "empty" stud wall)