Key Post: Attic Insulation.

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elkii

Guest
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...!
 
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.
 
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!!!
 
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.
 
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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You might need to lay extra battons on the existing beams to make sure they are above the height of the insualtaion
 
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,
 
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 !!!!
 
Its probably that the builder was doing some work and forgot to put it back.
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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).
 
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
 
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
 
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 ???? :D

efm
 
"Basically you are saying..."

...what I bet an electrician will tell you!
:lol
 
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.
 
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).
 
Re: "Basically you are saying..."

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

efm
 
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?
 
Re: Loft insulation or heat recovery system.

Geegee said:
My loft already has two layers of insulation laid in a criss-cross fashion
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Do you mean glass fibre rolls? Why criss-crossed and not just in a single layer? What depth in total?
 
Re: Loft insulation or heat recovery system.

Do you mean glass fibre rolls?
Click to expand...

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

Why criss-crossed and not just in a single layer?
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It traps any escaping heat where the insulation meets the joist.


What depth in total?
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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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