# Key Post:  Attic Insulation.



## elkii

I'm planning to put extra insulation in the attic in our new house before we fill it with junk. 

Is the standard insulation put in houses these days sufficient?? I'm assuming not..any idea what is the optimum level of fibreglass is..don't want to put in either too much or too little!!

Thanks again...!


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## ClubMan

[broken link removed] recommend at least 150mm/6 inches.


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## sunnyday

Can't say for sure what the optimun thickness is, but one thing to note is the following; the fibre glass type insulation normally used to insulate attics is by it's nature quite loose. That is to say it's not tightly compressed. If you do compress it, either by loading things on top of it, or by trying to pack in a double layer where there's really only sufficient clearance for one layer, you reduce its effectiveness.


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## elkii

Thanks clubman and sunnday , thats interesting about the compression factor. Does it require air pockets then to function correctly? We were thinking of laying attic boards (chipboard) on the final layer before piling in the boxes..maybe we'd better rethink that!!!


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## sunnyday

Hi elkii, I'm no expert, just going on opinion of a few builders. I'd suggest that if you fix the normal 6 inches between the joists and then fix chipboard, it should be a pretty good job. The chipboard will help keep the cooling breeze circulating in a properly ventilated attic from getting at the insulation too much, thus helping to reduce heat loss. By the way, foil backed slabs, or even insulated ones would also be a good help to reduce heat loss through the attic.


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## ClubMan

*Does it require air pockets then to function correctly? We were thinking of laying attic boards (chipboard) on the final layer before piling in the boxes..maybe we'd better rethink that!!!*

Yes - the air within the fiberglass helps to create an insulating barrier which helps retain heat. There should be no problem laying boards as long as the fiberglass is laid in the gaps between the beams as is normally the case. The fiberglass is normally not laid _across_ the beams so compression should not be an issue as long as you have c. 150mm clearance from the ceiling board to the top of the beams.


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## legend99

*..*

You might need to lay extra battons on the existing beams to make sure they are above the height of the insualtaion


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## Maceface

*Attic Insulation - where to put it*

Hey People,

New house and recently went up to the attic. 
Noticed that the area over the en-suite is not covered with insulation.
Now there is insulation for it up there, but is is pulled back away from the area.

Now my question is, should I fix it - put the insulation back over the area (over the ensuite).
The builder said something at the time about not having insulation over certain sections (such as over the lip of the roof because it cases condensation/dampness).

Anyone know what I should do?

Ta,


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## judge

When we got our house we noticed that some of the insulation had been pulled back here and there too. Its probably that the builder was doing some work and forgot to put it back. If its there, then there is no harm in putting it back. There is some missing under our water tanks but I have been told that this is so the heat will help stop the tank freezing !!!!


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## sunnyday

> Its probably that the builder was doing some work and forgot to put it back.


More like he just didn't bother to put it back! >D 
By all means put it back down. Like the judge says, the only place it should be missing is under the tank (which should itself be insulated also).


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## efm1

Quick further question regarding laying attic insulation.

We have downlighters (spots) in all the bedrooms upstairs in our house.  These are fitted through the ceiling - is it ok to cover these light fittings with standard fiberglass insulation ?

I think that the transformers for these lights can heat up - is there a fire risk if I lay the insulation over the light fittings ?

Am I just a big worrier ?

efm


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## Dr Moriarty

*Am I just a big worrier?*

You're damn right to worry about fire hazards in your home..!

The whole point of that fibreglass insulation is that it's capable of absorbing high temperatures without posing a fire risk — the stuff is virtually un-inflammable. But the danger might arise more from the fact that you're trapping heat that would otherwise normally escape away from your spotlight fittings. Are they metal or plastic? What's the bulb rating? Is there much paint in the surrounding area? What's the wiring like, etc.?

You could always try a test — cover them over, leave them turned on for a few hours and then go back in and see how hot they're getting (...carefully!). If they're not going to be left on constantly, and you're not getting any scorchy smells, you should be OK. (God, saying that gives me an awful sense of impending-doom-_and_-guilt-with-it...) On second thoughts — ask an electrician! :eek


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## efm1

*Re: Am I just a big worrier?*

Thanks for the advice Doc !

Basically you are saying "Just give it a bash and if the attic doesn't catch on fire then you'll be grand!" :lol 

.....OK........

Any electricians on this board ????  

efm


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## Dr Moriarty

*"Basically you are saying..."*

...what I bet an electrician will tell you!
:lol


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## askew70

*Re: "Basically you are saying..."*

I put down new insulation in our attic. It wasn't the typical older fibre-glass type insulation, it was a finer variation on that theme with a layer of plastic wrapped round it. Where I encountered spotlights, I just cut a hole in the insulation around the light (this might have been the recommendation on the packaging on the insulation, but I can't remember for sure). I think I cut a hole of about 8 inches or so in diameter. Over a year later the house is still standing  

As for the water tank, I added insulation underneath it, but wrapped some of the older insulation around the tank itself and made up a lid for the tank (with leftover chipboard from the attic flooring that I put down) with a 1-inch thick layer of polystyrene glued to the inside of the lid. Since having done this, our electric shower has been noticeably more effective - we don't have to turn the "heat" dial up on it as far as the water in the tank no longer gets as cold as it used to in winter. As a result, the shower doesn't have to work as hard to heat the water so it uses a little less electricity and the power of the water coming through isn't reduced by as much either. So basically, while insulating the water tank is a wise precaution, it also saves us some money on electricity too.


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## sunnyday

*Re: "Basically you are saying..."*

Under no circumstances should you cover the downlighters/spots as they need to release heat (upwards). Allow about 8 inches all around (as mentioned).


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## efm1

*Re: "Basically you are saying..."*

Thakks all for the replies - my insurance company also thanks you for stopping me burning the house down !

efm


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## Geegee

*Loft insulation or heat recovery system.*

When at the Ideal Homes exhibition recently I came across Iso Mega 6 reflective multifoil insulator for lofts.It is manufactured by a french company [broken link removed] and it's website is only in french. Apparently, it has the standard insulation equivalence of 250mm. My loft already has two layers of insulation laid in a criss-cross fashion and my reason for this query is that there was so much heat in the loft during the summer I was thinking about buying a Heat Recovery Ventilation system to harness this heat. 

Would it be better to keep the heat out of the loft in the first place by fitting the above-mentioned insulation or leave it as it is and fit the heat recovery system?


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## ClubMan

*Re: Loft insulation or heat recovery system.*



			
				Geegee said:
			
		

> My loft already has two layers of insulation laid in a criss-cross fashion


Do you mean glass fibre rolls? Why criss-crossed and not just in a single layer? What depth in total?


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## Geegee

*Re: Loft insulation or heat recovery system.*



> Do you mean glass fibre rolls?


 
The bottom layer, yes, the top layer is a quilt.



> Why criss-crossed and not just in a single layer?


 
It traps any escaping heat where the insulation meets the joist.




> What depth in total?


 
I'm not sure as i haven't moved in yet: if it is 100mm thick then 200mm in total or if 150mm thick then 300mm in total.


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## MAJJ

*Attic Insulation - Sheeps Wool vs Conventional?*

Hi Folks,

I'm about to close on my house, tomorrow if all is well. The first, of the many things I want to do, is the insulate the attic. We had a survey done before our purchase and he recommened we attend to this.

There are lots of great posts on the appoach. But I am interested in using sheeps wool and would be like to here opionions/actual experience with this compared to more conventional materials. 

I've read the material from the retailers but would love to hear more independent advice/pros/cons. Including longevity.

BTW - house has double glazing, including the doors front and back and has GFCH. I'm unsure about the quality of insulation ofthe external walls as the house is 30+ years old. I add this in case people suggest priorities 

Thanks


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## Sherman

*Re: Attic Insulation - Sheeps Wool vs Conventional?*

In terms of priorities the attic insulation costs a lot less than dry-lining/retro fitting insulation to the walls, is far far less messy, and has a more noticeable effect on your heating bills.


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## extopia

*Re: Attic Insulation - Sheeps Wool vs Conventional?*

Sheepswool is expensive (I'm sure you've priced via sites like http://www.sheepwoolinsulation.ie/) but I decided to go with it as I just can't abide fibreglass. The stuff is very very easy to work with and you can easily do it yourself - no scratching for days a la fibreglass. The marketing bumph says better U value, longer life etc etc - not sure how true this is, time will tell. But it certainly works! I also used their sound insulating joist strips and underlay, by the way, that works well too.

In terms of priorities, heat rises so attic insulation is the first thing to do. What did your surveyor say about the external wall insulation?


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## Lucret

*Re: Attic Insulation - Sheeps Wool vs Conventional?*

Make sure to take into account sagging by whatever insulation type you go for.  If you start off with 300mm, in ten yrs you may have a decreased depth which will affect the U value.  If you google on this you will get more info.
Icyene looks like a good insulation type and it doesn't off gas / sag.


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## Lucret

*Re: Loft insulation or heat recovery system.*

Could dust in the attic be an issue, the latest edition of self build mag has an article on a self builder who did something similar lately.


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## Leo

*Re: Loft insulation or heat recovery system.*

Heat recovery ventilation expells air from the rooms of the house and takes in fresh air from outside. The heat recovery part is related to the internal heat exchanger which transfers the heat from the expelled air to the fresh air coming into the house.

I don't think you'd want to consider a system which takes air from the attic into the house due to dust, etc. Also, during the summer when the attic reaches these high temperatures is generally the time when you want to keep the rest of the house cool, not make it warmer.
Leo


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## Geegee

*Re: Loft insulation or heat recovery system.*

AFAIK, the loft intake has dust filters fitted as standard and the rationale is that the fresh air is dragged into the loft from outside through the trickle flow vents in the soffit


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## NiallA

*Re: Loft insulation or heat recovery system.*



			
				Geegee said:
			
		

> Would it be better to keep the heat out of the loft in the first place by fitting the above-mentioned insulation or leave it as it is and fit the heat recovery system?


 
Why spend money on either.  The heat in the attic doesn't affect you, so why pay to keep it out,  in the summer you don't want it to heat your rooms, so why pay to heat them?

In the winter the attic is as cold as outside.


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## tibrok

*Re: Loft insulation or heat recovery system.*

I'm just wondering if anyone could please post the name of the Irish Distributer for Iso Mega 6? I've done a search on google and cannot find anything.


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## Lucret

*Re: Loft insulation or heat recovery system.*

Actis insulation agent at Tel 018365299


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## tibrok

*Re: Loft insulation or heat recovery system.*

Thanks for that.


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## patspost

*Insulating attic in old house*

A friend has an old farm house and was wondering what was the best way to insulate the attic. There is no hatch to access the attic.
The ceilings are reasonably high so putting in the insulation from below would be possible.

Would it be a case of putting up battons then insulation and then screwing on plasterboard ?, or would there be an easier way ?.
What type of insulation, rock wool or some kind or rigid polystyrene.
It would probably be easier to work with a board type insulation over the head than something like rock wool? 

Any suggestions hints appreciated;
Pat


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## z102

*Re: Insulating attic in old house*

First you should determine how much insultion you need. 
That depends on what is there, if nothing is there and you want to put it below the existing ceiling than you should put in about 200mm to be in compliance with the building regulations. And this is to be recommended , the resale value  and the comfort to live in it would be enhanced.
So if when you have decided the room height is good enough for that - for old buildings the building regs make exemptions from the mandatory 245cm - then you have to find the beams in the ceiling. 
If there is realy no access to the attic think about creating it, simply smash a hole into the plaster.
That is to find the beams and check their loadbearing, if they are rotten etc..and check the roof struckture if the house is worth the job.        Then you small make holes from above with a drill at the left and at the right of each beam at each end.
That is to give you a hint where you have the centres of each beam when you stand below them.
Then you mark the beam centres at the ceiling below and fill the drilled holes back again with some gipsum.
This is the first step, if you are still interested how it goes on (smiley) we go on tomorrow, o.K.?


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## patspost

*Re: Insulating attic in old house*

Many thanks for that H, still interested all right.
The taught of going into the attic doesn't appeal, due creepy crawlies and the likes, but if it has to be done, so be it.
It would be safe to assume there is no insulation, house 80 yrs old.
Working over head would a sheet type insulation material be better than a roll of rockwool type thing?.


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## minion

*Re: Insulating attic in old house*

You can get insulation sprayed in through small holes these days.
 after the job is done fill the holes with pollyfilla and paint the ceiling


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## z102

*Re: Insulating attic in old house*

Against the creepy crawleys you can get some sort of boilersuit with a hood, they come in white, are disposeable and some times seen on TV when the authoritys are catching chickens, check the recent TV news from Turkey. These boilersuits cost around €5-10 each. Adviseable is a dust mask as well as gloves.
On we go: After you found the timber structure sturdy and worth it you check with your plaster board supplier for " hangers " , these are strong metall wires divided in two pieces with a bended piece of bended steel plate in between the two. These hangers are screwed with one end into the roof joist at center. This is done on a distance of about 40cm. 
When this job is finished your room looks like a modern art gallery with these things dangling down from the ceiling.
Then you fix roof battons onto the other end of these hangers, paralel with the original ceiling beams/joists.
When you have these roof battons fixed then you level them. Here comes the metall plate holding the two hanger halfs: it gives you the possibility to change the height( or lenght)  of each hanger. So you get an absolute level ceiling . 
Leveling in small rooms is done with the aid of a spirit level, in larger rooms a laser level or a hose filled with water is used. The latter costs around €5-10. The laser is more expensive but can be hired as well, I have seen them in Lidl for €20 as far as I remember. I use the hose for that job, cheaper and less dangerous because there is no chance to burn out parts of the retina.
Then you get the electrician in, for the ceiling lights and maybe vents etc..
Fix all the way around the walls at the height of the new ceiling roof battons as well.This will give you the ability to screw the plaster boards secure to the wall. Quite often the amateur accustic builder saves on this, thinking tape and plaster will hold the ceiling. Which is wrong.
After that you lay your insulation on to the roof battons .
Which material you use doesn't matter, as long as it is doing it's job. Electric PVC insulated cables need protection when using EPS (Aeroboard etc.) which can be provided with a short piece of plastic pipe or ducting.
Sheeps wool or rock wool can be aplied directly to PVC cables.
Done so you aply the plaster board sheets. Better use screws than nails, nails are tricky for the amateur.
Check the plaster board manufacturers home pages for detailed advise on material and workmanship, some material providers have brochures, Collins DIY (library) is also a good resource of knowledge.
When using rock wool or glass wool then wear a mask, better use the wrapped and packed rolls of rock wool. B&Q sell them from the company Knauf , some advice how to use rock wool is to found here: http://www.eurima.org/using_mineral_wool/practical_tips.cfm  (thanks to our moderators who foud this site!)
When you closely look at the pictures provided by Eurima then you will see that they use no mask when working with the WRAPPED mineral wool. Otherwise always use a mask and goggles!


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## patspost

*Re: Insulating attic in old house*

Thanks for that advice Heinbloed, I didn't know about those wire hangers, but I have seen I suppose something similar used for stud partitions, when I say similar I mean using metal batons/studs instead of the usual tiber stud.

You have helped me to itemise the tasks involved, so we will investigate the ceiling and attic adn see how we get on from there.
Thanks again.


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## Berlin

*B&Q Attic Insulation*

Does anyone know the length and width of a roll of B&Q attic insulation? They can give me a price but nothing else, so I can't work out the cost per sq.metre for comparison purposes.


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## MAJJ

*Re: B&Q Attic Insulation*

These are written on the roles. I used knauff combi cut crown roll.
The dimensions for these will be on http://www.knaufinsulation.co.uk/cgi-bin/files/pdf/DATA Crown Loft Roll.pdf Crown Loft Roll.pdf. The last part is part of the link too!


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## JJJ

*Insulation Provider*

I did a search on attic insulation but all I found was reccommendations/information for people undertaking the attic insulation themselves...

Would anyone have reccommendations for attic insulation providers - for my parents house which is approx. 50 years old and had insulation done many years ago...

thanks


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## Berlin

*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)


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## whiplash

*Re: Insulation Provider*

Check out [broken link removed]


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## z102

*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.


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## Lucret

*Re: Insulation Provider*

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


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## ajsnr1

*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


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## Berlin

*Rockwool Insulation*

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


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## npgallag

*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


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## Touch Wood

*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?


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## Sue Ellen

*Re: Rockwool Insulation*

Hi Berlin,

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


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## Jo90

*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.


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## trekie

*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.


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## Berlin

*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.


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## z102

*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.


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## colmoc

*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.


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## z102

*Re: Insulation in attic*

What is your exact question?


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## Leo

*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


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## colmoc

*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.


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## bskinti

*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


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## z102

*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.


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## hotlips

*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


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## z102

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

Ask yourself why you want extra sheeps wool insulation. The mineral fibres of the gass wool wont go away by laying sheeps wool on/under it. 
If you want cheap insulation then go for glass wool. If you want half ways cheap insulation go for wrapped and packed glass wool. But if you want healthy insulation then change the house. Once loose mineral fibre has polluted a place it's very hard to get rid of it.
200mm glass/rock/sheeps wool is the legal minimum of roof insulation.
I used two 100mm layers of sheeps wool.
The recessed lights would have to be covered at their backside. This could be done by clay flowerpots for example. Clay because most likely the cable's insulation used at the lights are made from PVC which should not come into contact with PS (polystyrene). And plastic flower pots are made quiet often from the cheaper PS material. An alternative is changing the PVC cables to silicone cables. Or cover the existing ones in ducting.


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## hotlips

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

Thanks heinbloed. I will think about what we should do. I was thinking healthy but I also don't want to generate any unnecessary waste. I'm not too concerned about the cost. We won't be moving house though. Good idea with the flowerpots. 
I regularly read your posts by the way. Having lived for 8 years in Germany and Austria, I am pretty horrified by the standard and finish of many Irish houses.


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## Sue Ellen

Some other relevant key posts:

*Attics* 

Condensation
Conversion
Flooring
Ladders
Water tank
Windows


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## unfortunate

Just a quick note about the attic insulation - it may be pulled back away from ceiling lights that are installed through the plasterboard into the ceiling.  They can become extremely hot and so they can be a fire hazard


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## z102

If a ceiling light emits to much heat then it shouldn't be installed in the first place. All electrical equipment should state the purpose for which it is designed. Igniting a standard insulation material would be out of the scope. Talk to your electrician, he would know what/whos insurance is responsible for such a quality problem.


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## littletom

Hi, 
Joists in my attic is only 100mm high and I would like to put chip board after the insulation work. Will 100mm thick insulation be enough or do I have to add additional joists for a 200mm insulation thickness?

I don't know how to go about it. I don't want an extra bedroom in the attic but some storage space.

Any suggestions welcome!

Thanks


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## Razza

Heinbloed - do you have opinion on the merits of shredded paper (blown in) v sheepswool? Ecowise in Galway say you get the same level of insulation, but the paper is half the price.


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## ludermor

littletom said:


> Hi,
> Joists in my attic is only 100mm high and I would like to put chip board after the insulation work. Will 100mm thick insulation be enough or do I have to add additional joists for a 200mm insulation thickness?
> 
> I don't know how to go about it. I don't want an extra bedroom in the attic but some storage space.
> 
> Any suggestions welcome!
> 
> Thanks


 
If the joists are only 100mm then i would be worrying about bigger issues that the insulation. What is your reason for putting down the chipboard?


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## Leo

Razza, Heinbloed has been banned since that post, so will be unable to respond. Ask Ecowise for the U value of their product and ask what kind of guarantee they offer.

Littletom, the more insulation you can put in there the better. 150mm would be the recommended minimum.


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## littletom

ludermor said:


> If the joists are only 100mm then i would be worrying about bigger issues that the insulation. What is your reason for putting down the chipboard?


 
Hi Ludermor,

Thanks for the response. So do u think I should increase the height of the joists? I thought putting down chipboard will make it easier to walk on attic.


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## littletom

Leo said:


> Razza, Heinbloed has been banned since that post, so will be unable to respond. Ask Ecowise for the U value of their product and ask what kind of guarantee they offer.
> 
> Littletom, the more insulation you can put in there the better. 150mm would be the recommended minimum.


 
Thanks Leo. I would like to put 200mm, but the joists being only 100mm height, I won't be able to put down chip board for easy walking on the attic and storing things there.


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## Leo

Agreed, you should raise the height. Not 100% sure about how best to go about that. Obviously if you just add extra height to a section, then floor that to use for storage, you're putting weight on the joists that they weren't designed to carry. It depends on the layout  and whether the load can be easily transferred to walls, etc.


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## Guest109

I insulated my attic but i put the fibre glass between roof rafters, then 
covered it with plasterboard, floored the attic and have some degree of heat in that big void up there,and can also be used for storage /playroom etc


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## extopia

ainya said:


> have some degree of heat in that big void up there,and can also be used for storage /playroom etc



Have you been up there in winter? It'll be freezing (at least it should be if your floor insulation is doing its job!)


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## Sue Ellen

ainya said:


> I insulated my attic but i put the fibre glass between roof rafters, then
> covered it with plasterboard, floored the attic and have some degree of heat in that big void up there,and can also be used for storage /playroom etc


 
You should install a light as well as its a dangerous 'ol spot especially with all them spiders lurking ..........


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## additional

Hello, I have a query in relation to retro-insulating a converted attic of a bungalow.
The attic of our bungalow was converted into a room during the 80s however during the conversion, no insulation was placed underneath the floor board. Similarly the roof in the converted attic space was neither insulated adequately. This converted attic is not being used anymore and would only be used for storage if ever used again.
Again, this is probably a silly question, but is it worth while to lift up the floorboards and fill the gaps with insulation, or is the floorboard adequate and carpet enough insulation for the below living space? Or is there any other insulating solution instead of lifting up the floor boards as this would be considerable work. Again the house is not a warm house, so I do think the attic does require some form of insulation. The whole attic is not converted and the part the is not ''converted'' is insulated.


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## suzie

Hi all, 

Need to add additional insulation into my attic. Basically at the moment it has 60mm of Xtherm in between the joists. The joists are 100mm deep. So is it OK to lay a blanket in the opposite direction with this gap between the layers? Also noticed that B&Q are doing a sale on loft insulation at the moment and don't want to miss it again (like last year!!) if its good value. For example they are selling a Knauf Earth Blanket top up insulation (200mmx370mmx4m) for €13. Is that good value? The attic area is approx 10mx10m so would need about 65 blankets at a total cost of €845. Does that appear dear?

Also in places the Xtherm isn't a snug fit between the joists, can I plug these areas with say rockwool as it would seem easier to cut to shape etc?

Thanks

S.


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## richie_irl

Have a similar problem to Suzies.Joists are only 100mm deep.So what I  wanted to know is would it be ok to use 100mm deep glass wool in between the joists and 200mm opposite direction to give me 300mm in total?
Or could I go 200mm in between the joists and 200mm accross or would I be compressing the lower layer too much?
Thanks,
Richie


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## stevo

Does anyone know how Kingspan insulation compares to Glass wool insulation ? Am I correct in thinking they used in different situations ? 
ie Glass wool over the upstairs ceiling joists and Kingspan in the roof joists ?


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## richie_irl

richie_irl said:


> Have a similar problem to Suzies.Joists are only 100mm deep.So what I  wanted to know is would it be ok to use 100mm deep glass wool in between the joists and 200mm opposite direction to give me 300mm in total?
> Or could I go 200mm in between the joists and 200mm accross or would I be compressing the lower layer too much?
> Thanks,
> Richie



Anyone??


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## Cal04

*Re: Loft insulation or heat recovery system.*

Yeah, bit nervous as we have alot of spotlights in the house


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## davek36

the standard IS 10inc,  most companys will put down 2 layers of 6inc, all the attic should be done any where thats pulled up is because the sparks or plummers were working in that area and didn,t put it back down.. never cover down lighters/ spots, you can get covers for them...  the tank should be wrapped and pipes lagged.. do not insulate under the tank.. also don,t forget to do hatch door..   this is not just guess work  i am an insulator..any more questions just ask


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## aircobra19

Why don't you insulate under the tank?

Whats best for wrapping the tank?


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## Orga

I have an 15 year old house with fibre glass insulation, couldn't say how deep it is. In the attic newer insulation was laid by rolling it across the batons. The newer stuff is about 6inches deep I think and itlooks like it was just rolled out. Is this ok? What potential problems exists if any?


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## Squonk

aircobra19 said:


> Why don't you insulate under the tank?


 To stop the water from freezing


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## aircobra19

Squonk said:


> To stop the water from freezing


 
Ah...


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## davek36

stop the water from freezing.. you can wrap tank with fibre glass or you can buy a tank jacket...  one layer should be put between the battons the second layer is more a quilt can be put on top of first layer or countered rolled/blanket rolled   most builders rather it layed on top of first ....  the main problem of not rolling between battons  it will not be out to the eves   which will mean drafts .  6 inch will not be enough  after a few years the fibre glass will go soft..  put more on better off  save problems down the road    you will notice the difference..


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## LLDLY

Check out homebase they are doing great deals on insulation 6/7 euro on rolls


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## NHG

Our attic has aprox 6" of moy insulation which was installed when the house was being build 10yrs ago, we would like to upgrade our insulation and then put a floor over it (just for some storage, i.e. christmas decorations etc)

I have just been told about a product called alutherm quatro which covers 30 sq mtr (costs aprox €480 per roll ), I was told that I could leave in the existing insulation and roll this stuff across the timbers and then floor directly over this. When I asked about my recessed lights, I was told that it would be ok to cover over as this would not be in direct contact with the lights (we were planning of leaving a space around them, keeping the insulation well back and cutting a hole out in the osb board over each one to ensure that they had enough air circulation around them, I have even priced fire hoods to put over each one)

Anyone with any advise or who has used this product.  The product web site is www.aluthermo.com


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## 3CC

I understand that multi-layer foil products do not currently have irish Agrement Certification. I had a quick look at the website for Aluthermo and after a bit of searching, the thermal characteristics are supported by a calculation and relies on some other source for physical test results. It also seems to indicate that the calculations are only for heat transfer by radiation and not conduction which would be the main mechanism of heat transfer. 

I remain to be convinced on this.


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## VByrne

3CC said:


> I understand that multi-layer foil products do not currently have irish Agrement Certification. I had a quick look at the website for Aluthermo and after a bit of searching, the thermal characteristics are supported by a calculation and relies on some other source for physical test results. It also seems to indicate that the calculations are only for heat transfer by radiation and not conduction which would be the main mechanism of heat transfer.
> 
> I remain to be convinced on this.


 
Mineral fibre has no agrement cert either, in fact it has never been tested where there is air and moisture movement (Like a ventilated attic) it's used because it's been around for so long and no one questions it, not exactly best practice. 

This material requires still air to achieve it's advertised U-value, for it's use in an attic it has no fitness for a particular purpose cert anywhere, Cellulose has but you need to use ventilator trays in the soffit, I do not think it would be any different for mineral fibre.

The Irish Agrement Board will confirm this to be true.


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## corkonion

when insulating an attic always cover spotlights with ceramic spot-pots that have ventalation holes...these are quite expensive from insulation specialists... but the cheap flowerpots in B'nQ are identical...buy the ones with drainage holes


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## RMCF

If anybody lives near the border, keep an eye out for the heavily subsidised top-up insulation that B&Q are selling.

http://www.diy.com/diy/jsp/bq/templ..._offers.jsp&noleftnav=true&menu=specialoffers

Its £1 per roll packed in rolls of 3 for £3. I think you are allowed to buy 15 rolls max. This means you can insulation your entire loft in a 3bed semi for approx £40 (I think).

Only problem is, it sells out in mins when it goes on sale. I called to my local B&Q yesterday and they had none left. I had earlier seen a guy heading out to the RoI with a trailer stacked high with the stuff, so they did have some in. Probably just pot luck if you find it in stock.


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## NHG

My oh made boxes (aprox 2' long by height of joice) from fireline plaster board (8 x 4 cost €14.50) to cover recessed lights and transformer.  He said that there was a fierce breeze coming up from downstairs when he was covering them so alot of heat must have been escaping up through them.


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## corkonion

cool....the ceramic flower pots in b'nq are just a euro each...the same "spot pots" are 20 euro each


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## janabiyah

I recently replaced all the halogen lamps in my downlighters with LED lamps.

There is no heat from these and energy consumption is only a fraction of before.

So no need to worry about flower pots etc, and even better, you can just lay the insulation directly over the fitting.


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## niallo34

I'm looking to add more loft insulation in two houses - one mid-terrace and one semi-d both approx 25-30 years old

http://www.diy.com/diy/jsp/bq/nav.jsp?fh_location=//catalog01/en_GB/categories<{9372016}/categories<{9372050}/categories<{9372230}&fh_reftheme=promo_159792389,seeall,//catalog01/en_GB/categories<{9372016}/categories<{9372050}&fh_refview=summary&icamp=ns_6

Can anyone advise which of the products on the above link I should use

I know this was discussed on the thread but there seems to be conflicting opinions - will covering the attic floor in chipboard/ply after loading in between with insulation improve the insulation or cause problems?

Thanks..


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## VByrne

Hi niallo34,
If you compress any fibrous insulation like mineral fibre you reduce it's thermal resistance, which means you will not achieve the level of performance you require, if you are flooring out the attic look at some other materials, if you are just going to use it for storage then raise the base above the level of the mineral fibre, I hope this helps.


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## niallo34

V said:


> Hi niallo34,
> If you compress any fibrous insulation like mineral fibre you reduce it's thermal resistance, which means you will not achieve the level of performance you require, if you are flooring out the attic look at some other materials, if you are just going to use it for storage then raise the base above the level of the mineral fibre, I hope this helps.



Hi,

So as long as you cover the joists with ply/chipboard at a level where the mineral fibre (insulation) is not squashed down then it makes no difference to the insulation?

Can you advise which fibre from the B&Q link to use?

Thanks


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## VByrne

Hi,
They are all much the same, it's the density that's important, SEI recommend 270mm of mineral fibre, but if you use a material with a higher density it has more thermal resistance, it will cost more to purchase, but you should be able to use less, insulation is often overlooked as an important component in and about the house so don't just base it on price, if you do use mineral fibre it will degrade over time it's not a material I would use but it's up to you, a material that will last for the life time of a building in the long run will be far more cost effective, best of luck.


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## niallo34

Thanks for the info. I've called around most of the places listed and the likes of Brooks, Chadwicks etc seem far more expensive than B&Q etc

B&Q have shops own brand mineral fibre for €13.35 a roll - 200mm depth and 5.45sq mtr - sales there say it's made from the same material as what Brooks etc sells - is this true or should I pay the €22 on average for the same material that Brooks etc sells for a brand name?


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## AlbacoreA

V said:


> Hi niallo34,
> If you compress any fibrous insulation like mineral fibre you reduce it's thermal resistance, which means you will not achieve the level of performance you require, if you are flooring out the attic look at some other materials, if you are just going to use it for storage then raise the base above the level of the mineral fibre, I hope this helps.



What other materials


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## VByrne

Hi 
There's not much diffirence between them, if it comes down to price I'd go with B&Q, it's up to you.

To AlbacoreA,
As I work with foam insulation anything I say will seem to promote it's use, but there are other fibrous materials like Cotton, Wool, Hemp and some products made from Straw, these are all natural produce so will last for a long time, so in the long run will be far more cost effecitve, but they all suffer from the same problem as mineral fibre, they need vapour and air barriers as air and moisture movement will lower there thermal resistance, so they do not perform as good as they do in a lab. Foam insulation is not effected by moisture and in spray form neither is it by air-movement, and last for the life time of a building, have a look at a web site called www.sprayfoam.com any information you may require is there.


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## niallo34

Thanks again for the very informative info.

I know it's a kind of how long is a piece of string question but generally how many square meters are there in an average three bed semi attic?


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## VByrne

Hi,
An average 3 bed is about 55msq floor area, under the rafter, for a 2 pitch add about 10%, for a 3 pitch 15%, and a 4 side pitch add about 20%, these are approx.


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## durafoam

although sprayfoam.com is a good resource, you may find a more simple and direct answer on this site: http://www.dura-foam.com/ You'll find concise explanations on spray foam insulation related topics, including foam roofing and spray foam insulation.


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## redgap

*Re: Am I just a big worrier?*

If you have downlighters in your attic then keep all insulation a min 150mm from the fitting and transformer. 
This is highlighted in the sei website.


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## david ross

*Re: Am I just a big worrier?*



redgap said:


> If you have downlighters in your attic insulation a min 150mm from the fitting and transformer.
> This is highlighted in the sei website.


hi,
i agree to what you said


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## DesignA

What is the name of the insulation below. I couldn't find it there.

"B&Q have shops own brand mineral fibre for €13.35 a roll - 200mm depth and 5.45sq mtr"


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## joer

My house is about twenty years old.,quite cold,a bungalow. Can someone tell me what is the best type of Wall Insulation that can be pumped into the walls , if it is expensive and if there are good points and bad points .  
Thanks


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## MAJJ

Joer, I reckon given your situation you could gain a lot of knowledge for free by availing of the ESBs FREE Halo survey.  This should be a good start. You could then post up here for advice and to clarify the details.

To answer your question I think more information is needed, you need to ascertain the type of construction of your walls this will then allow people to advise you. 

For example if your house is like, mine 9" hollow blocks, there is no continuos cavity and hence this can't be pumped. Often the best way is to look at your walls via the air vents or the ESB box. 

You may have done all this before, so forgive me if so! Am no expert myself but have reviewed my options and learned a bit.




joer said:


> My house is about twenty years old.,quite cold,a bungalow. Can someone tell me what is the best type of Wall Insulation that can be pumped into the walls , if it is expensive and if there are good points and bad points .
> Thanks


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## joer

Thanks Majj,my house has the two rows of 4inch blocks with insulation in between.It is still a cold house. I have been told about the fibers and glue combination,from the people who use it but i have yet to hear from someone who has had it done.I would love to hear whether they noticed an improvement ,how much of an improvement,and roughly how long it took to notice.
Thanks


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## Firefly

Hi,

A bit confused.com this morning. I am looking to lay fibre insulation in my attic. Want to put down 300m. I can buy 100m in B&Q in rolls, but have fread that it is better to put the top layer running perpendicular to the lower layer. Do these need to be cut or just rolled out over the joists?

Thanks

F


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## justin

hi all i was just wondering has anyone used the blown in loose fill insulation in their attic?somethin like cellulose.my partner suffers from asthma and just wondering would it b dusty as its a loose material.


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## Leo

justin said:


> hi all i was just wondering has anyone used the blown in loose fill insulation in their attic?somethin like cellulose.my partner suffers from asthma and just wondering would it b dusty as its a loose material.


 
My parents got this done a couple of years ago. My mother also suffers with asthma, but has reported no ill-effects from it.

It will make any subsequent work in the attic difficult though. If you need any storage space, you'd be best use conventional insulation and flooring over this area prior to having the rest of it blown. The blown insulation also completely covers all wiring and light fittings, I'd also have niggling concerns about maintaining the ventilation gaps at the eaves.
Leo


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## justin

thanks for that leo
i`ve made boxes to cover the light fittings but big enough so the transformers are not too near the fittings.as for storage i`ve raised the floor in half the attic to allow the insulation underneath.the walls are currently in the process of being blown in(cellulose) and the house is extremly dusty.my biggest fear is not being able to enter attic because of dust.


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## Leo

In my experience, the attic is much less dusty than when they had the old fiber glass insulation up there.


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## Firefly

Hi,

Can anyone recommend the best type of insualtion roll to use for rolling down above the ceiling / between the joists? Also, would the beading be better?

Ta


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## Sandals

Had halo survey carried out who pointed out need for attic insualtion.

B&Q have knauf blankets 200mm thick 370w by 4000l for €13.70 buy two get one free. 

Had been trying to purchase downlight covers but was told by insulation company and two electrical stores, buy 6inch wavin pipe which is fireproof and rodent proof and cut twice as high as insulation, as they find the covers leds to more blown bulbs as heat builds up (or you can replace trad bulbs with led's for €10 each).


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## Firefly

Hi Sandals,

So is the idea to roll out the rolls of fibre between the joist and then just lay these blankets from B&Q over them to bring it up to 200m?

Another Q - I've been reading that fibre contracts over time - is it possible to put down rockwoll between the joists and then these B&Q blankets over, or does the type of insulation have to be the same?

Thanks

F


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## Sandals

we have scattered badly done layer of fibreglass itchy stuff down already but we need twice the amount that is down according to halo guy. so plan to fill in missing areas and then place these blankets over the joists at right angles.  The blacket is 200mm thick so hopefully more cosy house not leting heat escape to the attic.


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## Firefly

Hi,

I've recently insulated my attic floor. Put down 100m between the joists and 200m perpendicular to them. I've read here to keep underneath the water tank insulation-free to prevent freezing, but the question is: I am about to insulate the water tank - do I insulate the bottom of it also or do I leave this bare so that the heat rising from underneath it will get through? Also, should I cover the tank with an insulated top?
Tx
F


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## Firefly

Firefly said:


> Hi,
> 
> http://www.sheepwoolinsulation.ie/support/faq.asp
> 
> I've recently insulated my attic floor. Put down 100m between the joists and 200m perpendicular to them. I've read here to keep underneath the water tank insulation-free to prevent freezing, but the question is: I am about to insulate the water tank - do I insulate the bottom of it also or do I leave this bare so that the heat rising from underneath it will get through? Also, should I cover the tank with an insulated top?
> Tx
> F


 
Hi Firefly  

http://www.sheepwoolinsulation.ie/support/faq.asp

Your water tank should first be sealed to prevent dust and unwanted material from entering your supply. The tank should then be insulated around and on top to effectively keep it within the warm part of the house. Leave under the tank uninsulated, this way warm air from the room below will reduce the chances of your tank freezing in severe conditions.

F.


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## cbyr1983

Jo90 said:


> How did you find this company
> 
> 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.


 

I have this same problem, ceiling upstairs is sloped down to eaves. You would need to be extremely small and sprightly to get in there to stuff insulation down into that area. Particularly in the corners, and I imagine that there is actually no insulation whatsoever above my bathroom.

Risk is also that you block up the eaves. However, it has been suggested to me that most old houses' roofs are not airtight at all meaning that risk of blocking up eaves is very minimal.

Any thoughts on tackling this. There is no way I am going to knock out the plasterboard from below.


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## Sandals

Attic completed (thank god) space blankets brillant to handle and so easy to put into position but very costly, we ended up using 200mm thick knauf rolls from ganleys in athlone (20€ a roll) over rooms like unused bedrooms and bathrooms. these were hard for a female to handle and also hard to cut. first roll after lugging into corner of eaves found I couldnt roll it out as rafter too low so had to remove again and cut one small section off and then put in larger roll. 

hard to tell if making a difference as weather temp so warm outside and we'v no fire on for weeks but like to think money spent is well spent.


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## Firefly

Sandals said:


> Attic completed


 
Well done. It's tough work but the HUGE glass of wine after finishing the job makes it all worthwhile! Like you I'm nearly wanting a cold night (just 1 ) to see if it makes a difference.


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