insulating an attic

bugsntinas

i'm hopefully gonna insulate our attic next year and was after a bit of advice.we live in an old cottade with the bedrooms half in the roof how do you go about insulating down the sloped bits but not blocking up the air flow?

magicianz

Any chance of a small pic of like a cross section of what you want to do? Is the bedroom ceiling sloped? Just did a small bit of very basic stuff so i have a bit of interest in insulation ATM to see if i can improve in anyway

CBYR1983

With difficulty. If you can access it properly you could squeeze rigid boards down. Best job would be to pull down your plasterboard, then insulate between and below the joints.

Admittedly it's tempting to just stuff it in...

bugsntinas

the bedroom ceilings are sloped with only a small bit of flat ceiling in the middle.no pics as it has very limited access due to previous owner putting a studwall thru the hatch.
don't really want to be pulling down all the ceilings as we have to live there aswell and it wouldn't be fair on the wife and kids.
definately won't just pack it in because of the needed airflow.

gsxr1

you could screw insulated slabs to your existing ceiling. Would need taped or plastered. 50mm 8x4 boards are 35 euro each

Unless you pull down the old stuff i cant see any good way of doing it.

endasmail

put in kingspan insulation
if the rafters are 150mm put in 100mm insulation
cut the kingspan to the size between the rafters
fit it and push it down the roof

gsxr1

really the only way to do this is strip.
Trying to ram small bits of PU board in between rafters would be next to useless as even a 1mm gap in that type of insulation greatly decreases its thermal efficiency . I cant see how this would work at all. Rafters are very rarely perfectly parallel and would be a bad job for numerous reasons.

Even if you installed insulated plasterboard, you would be nowhere near the latest building regs.

Have a look here .



http://www.constructireland.ie/vb/showthread.php?t=910

endasmail

the chap has already said he doesnt want to strip it
any gaps left in the insulation can be filled with fibre insulation

martin46585

without a vapour barrier in between the insulation and the room, the warm moisture laden air will condensate behind the plasterboard leading to mould etc on the timber rafters.......as they say......hard to make and omelette without breaking the eggs

bugsntinas

please don't start arguing:D i do like the idea of using insulated plasterboard don't that stuff have a kind of vapour barrier incorporated into it aswell?

fodda

Excellent bit here on insulation. http://www.grow-your-own.ie/insulation.html

meercat

http://www.biobasedinsulation.ie/index.php
i have seen this spray foam done before
just to note,its a bugger to walk on joists after this is done though

gsxr1

endasmail wrote: »

the chap has already said he doesnt want to strip it
any gaps left in the insulation can be filled with fibre insulation

Do you what you are saying?
From above at the roof collor you intend to stick pu insulation. . Not possible . unless you are 2 foot tall

how do you intend using fiberglass to fill gaps that cant be seen or accessed . Again not possible.:rolleyes:

gsxr1

bugsntinas wrote: »

please don't start arguing:D i do like the idea of using insulated plasterboard don't that stuff have a kind of vapour barrier incorporated into it aswell?

I dont think the backing on the composite plaster board is a full vapour barrier . It is vapour check.

Vapour can get through the joints. But there is a special tape that can be applied.

bugsntinas

well i had to rip abit of the ceiling down to trace a burst pipe(turned out a joint seperated)and the gap between the roofing felt and the plasterboard is about6 inches so i think the plasterboard option is the one to go for.was looking at a site and there are 3 types 1 is minimum quality,1 was above that and then one that was high insulation quality with vapour barrier but very expensive.

endasmail

gsxr1 wrote: »

Do you what you are saying?
From above at the roof collor you intend to stick pu insulation. . Not possible . unless you are 2 foot tall

how do you intend using fiberglass to fill gaps that cant be seen or accessed . Again not possible.:rolleyes:

this coming from a lad that wanted to fit insulated plaster boards

bugsntinas

come on people lets no fall out please.
as said there is only about 6 inches of space so not gonna get much insulation up there anyway.

gsxr1

endasmail wrote: »

this coming from a lad that wanted to fit insulated plaster boards

yes.

are you sure you know whats going on here?