Fact or Fiction

Rob Keeble

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Location
GTA Ontario Canada
This question is for the pros that build and insulate buildings.

Its been bugging me for some time and i would simply like to get the facts without digging and unearthing all the specs.


I was told by a pro at the HD pro desk that one merit to using ROXUL the green batt insulation stuff over the pink fibreglass insulating stuff is that if you compress the green stuff you still get the same R value whereas if you compress the pink stuff it gets reduced.

The logic of the whole thing has me baffled given my thought was the insulating material achieved its insulating properties through the use of the "air gaps" that would exist between the strands/layers of the two types of material. So compress either and to me you loose that property.

BUt hey who am i to know. To be fair to the guy he was saying if you have say a corner covered by a stud or cut it incorrectly and need to fill the edge and push the green stuff in (ROXUL) you would not be affecting the R value. Whereas this is not the case with the pink stuff and by this i dont mean the solid pink foam sheets i mean the pink batts that goe between studd bays.

Anyone know the truth? :eek:
 
Rob,

Check this out: http://www.roxul.com/residential/how+to+install+roxul/exterior+walls

Item #2 says to not compress it as it reduces it's effectiveness.

Which contradicts this #2 http://www.roxul.com/residential/how+to+install+roxul

What I think {says it all right there :rofl:} they're saying is, like any loose style batting, is, to not over stuff the area your filling, as in...not trying to fit the R23{designed for 2x6 cavities} into a R15 design {2x4 opening}, the Roxul compressing is referring to the installation method, where-by the batt is slightly over-sized and you need to compress it to insert between the studs and it then rebounds itself to make a better fit than supposedly the glass fiber does.

Personally, I think the old pink standby works fine if properly installed, the real difference I feel is the fire rating of the Roxul which seems superior.... just my 2cents.gif
 
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