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cheyiennerascal
Aluminium vapour barrier
cheyiennerascal

Which side of the wall should aluminiun vapour barrier should be installed on, the exterior of the house or the interior and does it matter if it is single sided or double. Confused

canuk
Re: Aluminium vapour barrier
canuk

"aluminium vapor barrier" ?

canuk
Re: Aluminium vapour barrier
canuk
Quote:

Re: Aluminium foil Wrap
Quote:
Originally Posted by cheyiennerascal
I have heard that aluminium foil wrap or vapour barrier is a good product but I am confused about its application procedures. Is this product applied to the exterior of a building or to the inside(just behind the sheet rock) of these exterior walls. If used inside should plastic vapour barrier be install to give an air tight application. I can see foil breaking down in time. I have seen many homes in the past with aluminium leveling board on the exterior before vinyl siding goes up. :confused:

If you don't mind I'll move this message to your thread so others looking in can contribute.

Cheers.:)

__________________
I'm not familiar with "aluminum vapor barrier" as such.
However .... as you mention there are radiant barrier products that come in many forms. For example .... the "aluminum leveling board" used on the exterior before the siding is installed as a system for improving the insulating performance .

The theory behind this .... the foil would be used to "reflect" the infrared component of heat .... whether from the outside or the inside .... preventing heat gain or loss. So , with preventing heat gain or loss would increase the insulation performance ... in theory.

The fact that any vapor barrier's role is to prevent warm moist air from contacting cold air .... the method of application should be the same for the area you live in .... regardless of the material. In other words if you live in an area with cold winters then typically the vapor barrier should be correctly installed on the warm side (room).

Hope this helps. :)

goldhiller
Re: Aluminium vapour barrier
goldhiller
cheyiennerascal wrote:

Which side of the wall should aluminiun vapour barrier should be installed on, the exterior of the house or the interior and does it matter if it is single sided or double. Confused

Primarily, it depends upon your locale...if being used in a "standard" type of application.

If you live a significant heating zone, then it should face the interior of the house. If you live in the deep south (primarily a hot & humid cooling zone)...then it would face the exterior of the house.

If a 50-50 type of climate...you might even forego the vapor barrier altogether, which would allow the insulation and structural components to dry to both/either the interior or exterior side.

And... it can depend upon what you use for siding material. For instance...if you put a vapor barrier facing the interior AND installed foam-filled vinyl siding on the house as well.....you've created a "double vapor barrier". Any moisture that made it into the wall/roof cavities would have a tough time drying out to either side. Not a good practice. Think terrarium. Rotting of wood components and mold could easily result.

Engineering/designing structures needs to be considered/calculated as a *system*...and not as a one size fits all kinda deal...especially in this day and age of super-tight construction.

Am currently working on an early '70s ranch with stick-built cathedral ceilings thru-out. It has aluminum foil-faced FG batts up there and in the exterior walls. Am about to install membrane roofing over the entire roof (32 squares). First order of business was to install a ridge/soffit vent system cause once the membrane is applied...every rafter bay would become a potential terrarium.

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