Perlite Insulation

[stealthmagic27]

Anyone have any experience with Perlite loose fill insulation?

Looking to go this route for insulating my garage walls (cement block)

Thanks and happy holidays in advance!

 

[mygarageone]

You will be better off using foam board against the block wall , total coverage instead of just the core.

 

[BlackTalon]

perlite has a pretty low r-value (~2.8 per inch)

 

[anthony666]

perlite has a pretty low r-value (~2.8 per inch)

but it's wicked for growing weed in ....... apparently ..... so i'm told ... by a friend

 

[raddksn]

but it's wicked for growing weed in ....... apparently ..... so i'm told ... by a friend

Guys talk ya hear things!

 

[anthony666]

^ exactly

 

[stealthmagic27]

perlite has a pretty low r-value (~2.8 per inch)

So I can fill 8x8x16 hollow block and the r value will be the size of the hollow section x's 2.8?! That gives me an r value of almost 7. I think that's pretty damn good considering the cost is pretty cheap! And whatever is left over I can throw in my soil!

 

[buzz4041]

We use perlite to fill all the block walls in our substations and instrument houses in the plants we build. We do go the extra and do insulation board also as suggested by mygarageone. This helps to keep these big building stable due to all the heat sources of the switchgear and such. Do as much as you can afford. Perlite now and add board later as you go.

 

[stealthmagic27]

Thanks for the reply buzz, am I right with the R value if im filling 8x8x16 hollows? Not sure how big the hollow section is but say its about 4". Then 4" x R value(2.8) = 11.2?

 

[buddyboy]

if you're getting it for free, then go for it.

but think about this, the wall is air tight, so heat will travel through the block, the air cavity in the block will transmit very little heat so filling it with insulation will just keep the heat in the block longer.

imagine a metal cube, the inside empty, put a torch on one side of the cube, heat will transfer to the other side of the cube via the metal, not the air space.

 

[stealthmagic27]

I totally understand where your coming from. Its by no means free, but its a fraction of the cost then any other means of insulation. I can insulate the place for $160 (being only 12 x 22ish). The wall is not airtight, I can look down into hollows of the blocks.

 

[buddyboy]

me: I would stuff a little fiberglass insulation in the top cores just enough to fill the tops of the cores with some concrete to make it air tight. then rigid foam on the interior or exterior.

you need a continuous thermal break, honestly I think filling those cores with anything would be a waste of time and money.

you need to stop the heat from leaving your shop by keeping the heat from getting to the concrete (insulate on the inside) or keeping it in the concrete (insulate on the outside) you're not increasing the R value of the wall by filling the cavities

 

[stealthmagic27]

Hmm, now that you mention it i can feel a bit of cold air coming from the hollows. Hey ill give it a shot, Ill close up the tops of the blocks. Maybe I can throw up some insulation and siding once spring rolls around. Thanks again for the reply buddyboy