So my "soon™" father-in-law asked me a weird question.
> Can you put rock and glass wool on top of each other?
> If so, which goes on top? or bottom?
Of course I can Google - and I did - but I found tutorials, comparisons and stuff like that.
But the combination of two? Nope.
> inb4 why use both
He said he's got some leftover and he just bought enough rock wool to cover the entire surface.
I guess that would imply that the rock wool would go to the bottom of this thing?
Anyone got some spare helium + mask btw?
>>920917
OP, more info:
- They kinda think that if you put enough insulation on a house, you won't have to pay for the heating.
- He read an article about how heat goes away due to the cold ceiling - so he went to the second floor - which was not used, but fully built - and he destroyed all the walls there, etc.
He zeroed the second floor in 2 days.
- He plans to cover the floor of said second floor with the wool.
So.. enough back story.
If you put these two fucks on top of each other, will that cause any trouble in the summer heat, or anything like that?
>>920917
no one insulates with wool in the US?
>>920944
Read sticky. This is a slow board. Stop bumping it unless it falls down a few pages.
You can use both but it will never be 100% effective as a heat insulator.
Heat loss will still occur, insulation just reduces the amount and slows the process.
Your in law is a moron.
>>920963
> Your in law is a moron.
I have discovered that a long time ago.
Do you have a tip for which should on top or bottom?
Will this mix-up cause any fungus or things like that?
Seriously I just want to give him "something", like some info.
>>920970
It depends on what it's like. I'd use the 'looser' fibre sheet under the firmer stuff and I've found glass fibre sheets to be quite flexible. I think a general rule of thumb with insulation is the firmer the better, as is phenolic insulation solid in make up and a brilliant insulator.
Hope that makes sense.
>>920975
yeah sure, makes sense.
the fibre/glass is the lighter one.
So...
######## rock wool
+++++++ fibre/glass wool
________ floor of second level
And where do you place the insulation plastic sheet?
He bought this kind:
http://www.masterplast.hu/mastermax_3_classic_mc
>>920917
yes you can stack them, but there is no point, because ideally you want to get the entire surfaces (walls and roof) to have a uniform insulation value otherwise you will just get cold spots at some place and make eg a corner that is slightly colder than everywhere else in the room which is fucking retarded.
but yes, you can use both, you can stack them however you want and it will perform the same. as long as it fits into whatever cavity you are putting them into.
>zeroing a second floor to put insulation
this is fucking retarded literally, as in REALLY fucking retarded, because there is no point, you should have insulated the roof. now you have lost an entire FLOOR of usable space. you have basically turned an entire floor into an uninsulated attic. this is ultimate level of stupid.
it's the air trapped by the fibres that does the bulk of the insulating work.
you can stack whatever until the bottom layer starts to compress from the weight and lose insulation value.
you should probably shoot the meth addled nig nog before he re-mortgages your house to feed his addictions. /pol
>>920978
> this is fucking retarded literally, as in REALLY fucking retarded, because there is no point, you should have insulated the roof. now you have lost an entire FLOOR of usable space. you have basically turned an entire floor into an uninsulated attic. this is ultimate level of stupid.
I could tell stories for hours - but I don't think that would be on-topic for /diy/.
Just for the sake of 'completeness'...
>>920982
cont'd:
> Guy hears that condensing furnaces are very efficient
> Think this means his gas bill will be like 5% of the current amount
> Old gas furnace is dying again
> Instead of repair, they spend a fortune on a new condensing furnace and install
... This is where it turns comedy-gold-tier.
> Gas bill is not lower as suspected...
> In order to keep bill low, they don't even heat up the home to 21C or 20C
> Moisture level is around 80%, house is cold, so fungus everywhere
> He hears that radiators work with magic, and somehow are more efficient than floor water heating
> He buys and installs like 10 radiators around the house
> They are not even used even now
> After spending like almost all his savings, he is now on the quest to insulate the entire house from outside, on second level (see above), etc.
All I want now is some sweet helium. Or vodka. Or both.
>>920984
If no one is willing to tell him he is an idiot, you need to be the one to do it otherwise he will die like a little bitch who spent all his fucking life fighting the cold when it should be a simple fucking thing
>>920985
Well I told him that it's simple physics, but he is the kind of person who believes everything he hears.
One guy told him the radiator thing, he ate it up.
Other fella told him that the wall of his house is insulated from outside, and now he only have to heat it up once per day - and it remains warm.
He is like a damn robot, can do hard work at 35C for 12 hours without any food or drink...
But yeah, this is where he falls short.
Thanks for the replies everyone.
I will just tell him that it would not make any sense to lay them on top of each other.
(He could have just picked a "wider" insulation.)
>>920981
>air does the insulation
oh so that how it works??? lemme destroy my cold brick walls and rip off the roof, get naked and sit outside by the computer. cant wait to be all warm and insulated by the huge amounts of surrounding air! hell, id be basicly insulated by the whole atmosphere!
>>920997
I think you missed the first few words of his reply.
>>920999
>air trapped by fibers
>air trapped by the planet
same thing
>>921001
obvious blank is obvious
>>921001
Pffff fuck yeah why not! Makes as much sense as leveling a floor in the house to insulate between levels this is fucking genius
>>920917
>>920920
It will be fine. You are only trying to slow down heat transfer. Either from inside to outside or reverse. In both cases, more insulation is better.
In the summer it means you are cooling the inside and the heat using an AC unit. Any other electronic and people will create heat, but heat from outside won't penetrate so fast that the AC can't take care of it a lot easier.
Just don't do something like run your oven inside to cook food and such in the middle of summer. BBQ or something outside instead where the heat can escape.
>>920917
You don't want to compress the glass insulation, more depth == better R value. Put down the wool first, then the fiberglass, depending on the temperature variants you may want to consider a vapor barrier on top of the insulation. My choice would be Wool, then about a meter of blown insulation.
>>921001
Open air is free to flow and transport heat by convection. Air forms a thin film that sort of sticks to the surface of solid objects, so close fibers like fiberglass hold the air still. Once still, air's high resistance to heat conduction provides most of the insulation value of fiberglass or other fibrous insulation.
>>920977
Just at a guess, I'd put it on the floor. Justify it by calling it an infiltration barrier.
>>920977
>http://www.masterplast.hu/mastermax_3_classic_mc
>Vapour-permeable and watertight functional membrane
That's a moisture barrier for roofing, not a vapor barrier for insulation. It won't do anything there unless the roof leaks. What you should get is a vapor barrier, which goes on the warm side of the insulation to stop water vapor from moving through the insulation and condensing on the cool side.
>>921169
why dont you use bags/boexes filled by high pressure air then? it would have much more air in it, wothout any stupid fibers taking up the volume
>>921199
Pressurizing the air would increase its density, increasing its heat transmission. Also, the convection-preventing film of air is less than a millimeter thick. The air would happily form convection cells to transport heat across boxes or bags. To get effective insulation from air, it has to be held in place by physical structures spaced very close together so that there is no air that is not in a surface film.
>>921205
>air does the insulation
>more air does less insulation
:|
>>921242
The more density, the better heat conduction, all other things being equal.
The air in the balloons would definitely form heat cells and that'd ruin its R value.
https://en.wikipedia.org/wiki/Heat_transfer#Convection_vs._conduction
If you could make a carbon fiber epoxy vacuum chamber that'd be better than traditional insulation, but if you filled it with air it would suck.
We use air because we can't afford to make everyone's attic a vacuum chamber.
>>921264
>earth is insulated by the vacuum of space
:|
>>921242
Heat transportation through a gas is proportional to the particle density and inversely proportional to particle speed. Most gases at the same temperature and pressure have about the same particle density. Pressurizing air increases particle density and therefore heat transmission. One thing that's done to improve insulation values in windows and some other applications is to use a heavier gas in place of air. Since temperature is average kinetic energy, and kinetic energy is Mv^2/2, a gas composed of more massive particles (like argon) will have a lower particle speed than air at a given temperature, so it conducts heat more slowly. That said, air's particle density is low enough that it has a low enough heat conduction for most purposes if it can be kept still. Hence fiber insulation.
>>921266
Vacuum prevents conduction and convection but allows radiation (sunlight). Really good insulation like on Dewar flasks and spacecraft use mirrored vacuum chambers to prevent all three modes of heat transfer.
>>921267
Correction: proportional to particle speed
>>921266
Dude. I don't know. I'm sorry you slept through highschool physics and want 4chan to spoon feed it to you because you don't understand.
:|
>>921267
Insulate house with a vaccuum. Shoot it into space.
