# Rockwool Insulation



## rmdt (4 Dec 2008)

What thickness of Rockwool do I need to achieve a u-value of 0.12 when insulating my attic (between/over ceiling joists)?

Also what sort of prices are people being quoted for rolls of rockwool?

Joists are 400mm spacing


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## joker538 (4 Dec 2008)

Have a look at this it should be able to help..
http://www.rockwool.co.uk/graphics/RW-GB-implementation/datasheets/Roll.pdf


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## HJT (5 Dec 2008)

Just pricing Rockwool at the moment. Prices for a 6 meter roll vary from 19e to 22.50 a roll in the Tullamore, Mullingar, Killucan area


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## rmdt (5 Dec 2008)

HJT,

What thickness is the insulation you are pricing?


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## delboy159 (5 Dec 2008)

I am using fibreglass instead of rockwoll for roof insulation.  I use the rockwool for internal studded walls as it has better sound insulation... Fibreglass was cheaper than rockwool when I was purchasing...  In Laois you can nab a 7m2 roll of fibreglass for between €17.85 to €18.50 (or a lot more if you want).. I paid the 18.50, 2 weeks later another builder provider went down to 17.85 - I was raging...

Does 300mm really get you 0.11/0.12 area, didn't think it got that good a U-Value!


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## davek36 (5 Dec 2008)

your better of using fibreglass insulation   2 layers of 150m     i fit it every day of the week and all say its great


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## rmdt (8 Dec 2008)

Thanks guys,

I know that fibreglass is cheaper but there is no way that I will use it as find it terrible stuff to work with and will be laying it myself!

Has anyone an experience of blown rockwool insulation?  How does it compare pricewise to laying rolls of rockwool yourself?

Would also be interested to hear of peoples opinions of the blown paper insulation.

Thanks


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## tosullivan (8 Dec 2008)

get the Knauf Space Blankets...its fiberglass is a roll covered in plastic.  Easy to roll out


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## BarneyMc (8 Dec 2008)

rmdt said:


> I know that fibreglass is cheaper but there is no way that I will use it as find it terrible stuff to work with and will be laying it myself!


 
I got 6" fibre glass (not itchy at all) roll insulation (made by British Gas) in B&Q in the north for £10 a roll. I think it covers about 6 sq metres. Very good for top up insulation.


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## sydthebeat (8 Dec 2008)

joker538 said:


> Have a look at this it should be able to help..
> http://www.rockwool.co.uk/graphics/RW-GB-implementation/datasheets/Roll.pdf


 
those u value quotations are extremely generous to say the least.....


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## Franm (8 Dec 2008)

Note also that it assumes that you also have 100mm between the joists.

http://www.rockwool.co.uk/graphics/RW-GB-implementation/datasheets/Roll.pdf


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## sydthebeat (8 Dec 2008)

Franm said:


> Note also that it assumes that you also have 100mm between the joists.
> 
> http://www.rockwool.co.uk/graphics/RW-GB-implementation/datasheets/Roll.pdf


 
that makes more sense...

400mm would give you about 0.11 alright....


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## ninsaga (8 Dec 2008)

BarneyMc said:


> I got 6" fibre glass (not itchy at all) roll insulation (made by British Gas) in B&Q in the north for £10 a roll. I think it covers about 6 sq metres. Very good for top up insulation.



B&Q are selling 200mm British Gas stuff for €13 a roll - & it does itch I can tell ya that much!


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## BarneyMc (8 Dec 2008)

ninsaga said:


> B&Q are selling 200mm British Gas stuff for €13 a roll - & it does itch I can tell ya that much!


 
didn't itch at all for me... I can tell ya that much


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## davek36 (8 Dec 2008)

if you do find that it itch,s  have a cold shower followed by a hot shower


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## HJT (8 Dec 2008)

HJT said:


> Just pricing Rockwool at the moment. Prices for a 6 meter roll vary from 19e to 22.50 a roll in the Tullamore, Mullingar, Killucan area



150 mm thickness


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## ninsaga (8 Dec 2008)

BarneyMc said:


> didn't itch at all for me... I can tell ya that much



I accidentally brushed my arms across it when installing & the fibers embedded - not nice at all.......nevertheless here's a dare for ya BarneyMc - grab a fistfull of this stuff - stuff it down your jocks & take the dog for a walk


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