Insulating my attic, what's the best stuff to use?

trevorbrady

we have a 1970s built bungalow bought in the days before BER certification etc. The original part of the house (as opposed to the 2005 extension built before we bought) is noticably colder than the extension. The outer walls have the little rounds scars high up from where they were (presumably) pumped with cavity insulation. So I'm suspecting the ceiling it where a lot of the heat loss is occurring. There is a single squished layer of yellow glass fibre insulation up there.

I'm considering replacing the current loft insulation with new stuff and I've begun doing some research. I see the recommended depth is 12" made up from two layers criss-crossed. The attic/roof space is an old design and with rafters and joists everywhere there is no hope of flooring it so it's just insulation I'm concerned with.

What I'm looking for is recommendations for what the best stuff to use is. I honestly have no idea so I'm open to advice...

BryanF

trevorbrady wrote: »

we have a 1970s built bungalow bought in the days before BER certification etc. The original part of the house (as opposed to the 2005 extension built before we bought) is noticably colder than the extension. The outer walls have the little rounds scars high up from where they were (presumably) pumped with cavity insulation. So I'm suspecting the ceiling it where a lot of the heat loss is occurring. There is a single squished layer of yellow glass fibre insulation up there.

I'm considering replacing the current loft insulation with new stuff and I've begun doing some research. I see the recommended depth is 12" made up from two layers criss-crossed. The attic/roof space is an old design and with rafters and joists everywhere there is no hope of flooring it so it's just insulation I'm concerned with.

What I'm looking for is recommendations for what the best stuff to use is. I honestly have no idea so I'm open to advice...

Environmental scale:

1. sheepswool or cellulose
2. mineral wool (rockwool) or recycled plastic bottles (earthwool) etc
3. PIR boards (kingspan xratherm etc

lowest cost scale

1. comparative cost mineral wool, recycled plastic, cellulose
2. PIR
3. sheepswool

do be careful to leave adequate venting at the eaves (50mm continuous ventilation)
also mark location of wiring & extract vents etc
and insulate pipework and watertank preferably with PIR

Carlow52

Have a look here
http://www.boards.ie/vbulletin/showthread.php?p=74820519

I prefer loose cellulose for reason s stated in the above thread

slimjimmc

Usually there's no need to replace the old stuff, just add more insulation to it.

heinbloed

As Slimjimmc said already: it might be the best solution to leave the old mineral fibre where it is and top it up with new insulant.

If it is shredded mineral fibre then close the hatch and stay away from it. It is carcinogenic. Shredded mineralfibre contains small particles which are a high-risk material (the OP spoke about cavity wall filling being present).

Here the WHO statement on mineral fibres, from chapter 8 onwards:

http://www.euro.who.int/__data/assets/pdf_file/0005/74732/E71922.pdf


All mineral fibres can be carcinogenic, those mineral wool insulants manufactured before the year 2000 or shredded afterwards in particular.
In 2000 as -far as I remember-the manufacturers had to switch production methods because of this health risk.

Knauf offered a wrapped-and-packed mineral wool for a while, but with nearly twice the price of the naked material they had no chance in the broader cowboy arena.

Some idiots still shred it and blow it into habitated houses. Filling cavity walls and "doing the attick for cheap in one go". No bother on the health impact for others, the quick buck is so tempting....

So be carefull, OP.

Protective gear is available from most building material supliers. As the material, but not that cheap.....