Key Post: Attic Insulation.

Re: B&Q Attic Insulation

Thanks for that Majj. When I went to B&Q Athlone they were sold out, so I couldn't look at the rolls, and the salesman didn't know the dimensions. Just wanted to compare with Brooks, who have a sale on at the moment. BTW, if anyone is interested, their price is €2.66 per sq.metre, which is pretty good. (That's for 100mm, 150mm and 200mm rolls)

Re: Insulation Provider

Check out [broken link removed]

Re: B&Q Attic Insulation

I thought the thicker the insulation the more expensive the price / m2 ....? For insulation material the reference price is stated ( in builders circles ) per m3.

Re: Insulation Provider

Try B&Q or Homebase they have pre cut insulation rolls that makes DIY easy.

Re: Insulation Provider

if you look up help the age'ed they actually do insulation for free for the elderly i assume both parents are pensioners there are also grants available from dublin city council as far as i know

Rockwool Insulation

Can anyone tell me what rockwool is? Is it better than the normal fibreglass stuff? Thanks.

Re: Rockwool Insulation

Berlin....the advantage of rockwool over fiberglass is that it has better sound insulation quailities...think the thermal qualities are similar....as far as i know

Re: Rockwool Insulation

Rockwool has a higher mass and regulates the heat inside the house better than fibreglass.
Rockwool takes in heat slower and lets it out slower.
Rockwool melts at higher temperatures so is better in the case of fire.
Both have the same U-value.
The old problems with fibreglass was that it collapsed in attics giving only half the U-value.
Also guys said it was very itchy. Both of these problems have now been overcome according to the manufacturers.
There are other issues which are worth considering like the ability of both materials to work when they become moist.
Maybe somebody would like to comment.
I heard that if fibreglass takes in 30% of its weight in water it looses 90% of its insulation ability.
Maybe somebody would like to comment.
Sheeps wool works when moist but to what extent?

Re: Rockwool Insulation

Hi Berlin,

There is some discussion on rockwool in the key post on Insulation and this co. also [broken link removed]

Re: Insulation Provider

How did you find this company [broken link removed]

and what sort of price did they quote for insulating the attic, ours is not a straight forward one as whilst partially floored it needs insulating in the eaves replacing which are difficult to access.

i know it can be done DIY but dont have time and dont fancy a few days crawling around attic like an eejit.

what cost of attic insulation

anyone got a rough idea of how thick insulation should be and much it would cost to insulate the attic of an average three bed house.

Re: what cost of attic insulation

As far as I know, the depth of the insulation depends on the depth of the roofing joists in your attic. That's if you intend to lay boards on top, as the insulation loses some effectiveness if compressed. Otherwise I think you can lay a double layer crossways. We've just bought our insulation for a 192 sq.metre bungalow and it cost just under €500. I suppose it would be less for a 2 storey as the roof space would be smaller.

Re: what cost of attic insulation

The building regulations -or better speaking- the technical guidelines demand about 20cm (glass wool or a similar insulating material) in attic spaces. The U-value is important,so to figure out the U-value check the SEI page at http://www.sei.ie/ ,as well for some advice on how to do it.
Once you are at the job put some extra insulation into the attic, it won't cost much extra but saves a lot of energy.

Insulation in attic

This is probably a no brainer but I have a new house with a converted attic and was wondering if there should be insulation on the inside of the roof in the crawl space of the attic. The stud wall is insulated as well as between the joists in the attic "floor" but I can see the felt on the inside of the roof. Surely this would cause substantial heat-loss in a house.

Any advice much appreciated.

Re: Insulation in attic

What is your exact question?

Re: Insulation in attic

If the walls and above the downstairs ceiling are insulated, you should be fine. Can you tell if the ceiling of the converted section is insulated? You should be able to see the roof felt in the open section of the attic, this is a ventillated space, so insulation at roof level would be a waste.
Leo

Re: Insulation in attic

Sorry Heinbloed. I guess the question is:
Should the house roof (at the felt) have insulation if the converted attic walls (at the stud) are insulated.

Thanks for the response Leo. I'll have a look over the w/e to see if the ceiling is insulated. Might be difficult to tell as it is a very confined space. Anyway. leave it with me.

Re: Insulation in attic

There should be insulation directly over all celings whether its in the crawl area beside studs or over the stud areas and in the sloped celings ie: all around living area is insulated

Re: Insulation in attic

Sorry, Colmoc, I might have sounded a bit duff.
But sure, all over the living space should be an insulating surface/wall. If going for insulation between the rafters make sure that the felt isn't touched by the insulation material. The reason for this is that the felt will be cold and air that touches this felt contains a certain amount of water, vapour. This water will settle on the felt, similar to the alcohol in a still or the damp at a bathroom window. This water should be able to run down freely. If it's hindered to do so by the insulation it will trickle into the insulation material. Like a sponge that takes up a puddle. And then the insulation material will sack, losing it's air content (replaced by water) and therefore loose it's insulation propertys. That is beside the point that mould would grow on it and that the wet material might cause further demage to timber and plaster board.
I lived in a similar situation: The slope was covered by a build-in cupboard and nothing of insulation behind it. These a gangster builders, one man alone on the side couldn't have done that without being noticed by the other builders,engeneers, architects.
Check your house further for other faults as well.

Sheeps wool insulation, how much and what about existing glass fibre?

Hi all

I've searched the forum and also read the key post on insulation. I hope I'm not duplicating anything.

I'm still not sure with how to proceed with increasing the insulation in our attic. Currently there is just the yellow glass fibre which was installed by the builders. I haven't measured the depth but I would guess it's 4"-6".The attic is just partially floored near the trapdoor and there are recessed lights in the bedrooms below.

If we really want to ramp up our attic insulation and want to use sheeps wool, what do we do with the existing glass fibre and what about the recessed lights?

Do we lift the glass fibre, lay the wool on the plasterboard between the joists and then just leave the fibre loose on top? I presume we have to cut holes around the lights.

Also, just wondering what thickness of sheeps wool would be optimal for maximum benefit. I'm looking on [broken link removed] and it seems to come in 60mm, 80mm and 100mm. Is one layer of 100mm pretty good or would some people use 2 layers bring it to 200mm?

If we floor the attic later, I presume we would remove the glass fibre altogether as we would not want to compress it.

If anyone has done this, I'd be interested to hear how you got on and if you noticed a cosier house with less need to use heating as a result!

Many thanks
Helen