Attic Insulation

liam7831

Need to do my attic, house was built circa 1983 so hardly any insulation up there. Its a 3 bed semi. Is fiberglass rolls still the best to use. I see you can get 100, 150 & 200 mill rolls. Am I best just go with 200?
I know someone who got theirs done with the EXTRATHERM sheets, seems easier to install but dunno which is better. Opinions & advice welcome.

Big Cheese

I have been looking at insulating my attic too. You need to check the specs of the insulation to see which gives you the best U Value. If using rolls you are best to lay 100mm in between the rafters and then put 200mm over that, crossways. Leave a gap near the edge to allow air in to prevent sweating. I have found Knauf 200mm rolls on adverts for 18.50 per roll. Woodies also have it on special at around 19.99. Hopefully picking mine up on Monday and doing it then. Had looked at spray foam but out of price range. Don't know much about rigid boards tbh

liam7831

Big Cheese wrote: »

I have been looking at insulating my attic too. You need to check the specs of the insulation to see which gives you the best U Value. If using rolls you are best to lay 100mm in between the rafters and then put 200mm over that, crossways. Leave a gap near the edge to allow air in to prevent sweating. I have found Knauf 200mm rolls on adverts for 18.50 per roll. Woodies also have it on special at around 19.99. Hopefully picking mine up on Monday and doing it then. Had looked at spray foam but out of price range. Don't know much about rigid boards tbh

Thanks for reply & advice, I see Knauf is much cheaper than Rockwoll, any particular reason for that I wonder other than not being as well known?

Payton

I insulated my attic last year. I used Knuaf earthwool 200mm thick, it made a big difference and done it in little over a day. I left the old fiberglass insulation there as it would have been too messy to remove.

liam7831

Payton wrote: »

I insulated my attic last year. I used Knuaf earthwool 200mm thick, it made a big difference and done it in little over a day. I left the old fiberglass insulation there as it would have been too messy to remove.

Where did you buy it? Did you guesstimate the amount you would need to buy?

Payton

liam7831 wrote: »

Where did you buy it? Did you guesstimate the amount you would need to buy?

I bought it in Smith's builders providers in walkinstown. I have a little over a roll left over. I measured the inside of the house front window to back window and likewise with the width and add roughly 40cm on to each measurement (external walls) and do the maths as per sq meter. Better to have more than less.

Payton

Woodies are selling 200mm earthwool for €20 per roll

Sleeper12

liam7831 wrote: »

Thanks for reply & advice, I see Knauf is much cheaper than Rockwoll, any particular reason for that I wonder other than not being as well known?

Knauf is better than fiberglass & rockwool. It's easier to install as it is not hard on the skin or on the breathing.