Attic insulation

missloulou

Hi,

with all this talk of Government insulation Schemes, what depth should the attic insulation be nowadays?

Thanks

Lou

RKQ

As deep as possible!
IMO 300mm of fibre glass is now standard. So if you had 150mm ceiling joist you would put 150mm fibre glass between the joist and 150mm perpendicular to the joists.

If you did have 150mm deep joists, I'd recommend 150mm between the joists and 200mm perpendicular. Giving 350mm overall.

JohnButler

Hi,

no less than 250mm. That is 100mm between joists and 150mm across joists.

JB

shovel

Hi.

Is it ok to leave the wireing between the two layers of insulation.

I only have about 3" insulation between joists with the wireing on top in my attic which is floored

Would like to take up the floor and lay more but can't lift the wireing enough to put insulation underneath it.

RKQ

shovel wrote: »

Is it ok to leave the wireing between the two layers of insulation.

No, insulation can cause the wires to overheat, causing fire. Leave a wide gap beside the cables.

shovel

Cheers, Thanks for that.

The insulation would be very patchy then

Cables all over the attic and no give in them at all to put any extra insulation over joists

joefromayo

What type of insulation do you use in your attic?

pseudonym1

Matt Cooper was discusing it on his show yesterday - there are grants available to get your attic c tested checking its energy efficinecy. There are stipulations but think it was about a 1/3 of the cost of insulation may be grant aided.
This creates some jobs addresses energy issues and give builders way of work.

yop

Someone has said that they had started to up the prices of insulation already. Has anyone got a docket with the price of insulation that tehy could give us an idea of what it costs per roll of say Fibreglass, rockwool etc.

shovel

There is only 4" joists and 4" fibre insulation in the attic.ply floor is screwed to 2"x1" lengths which are screwed across joists
I am thinking of taking up the floor and 2"x1"and lenghten the cables using junction boxes.

Then put down 6" x2" lengths across the joists and lay new 6" insulation between them and put the floor down again.

Will i need to use full lengths of 6x2? (expensive!) and could i incorperate the 2x1's somehow to keep the cost down.

how do i fix the 6x2 to the joist -screws or metal straps +screws?

any advice appreciated

shovel

sorry lads, post above not showing.

Carlow52

RKQ wrote: »

No, insulation can cause the wires to overheat, causing fire. Leave a wide gap beside the cables.

see the link in this post for current guidance on cable clearance

http://boards.ie/vbulletin/showthread.php?t=2055483835