Thursday, December 20, 2012

Things to Know About Continuous Insulation

Steel is a pretty good conductor of heat, its R-Value is really low, however it is known that traditionally the area of a wall or ceiling bridged by steel is so small that the overall loss of heat is relatively minor and recently, research has shown that this is false.  If bridging of steel in a wall is equal to less than one tenth or 1 percent of the total wall area, it will allow for heat to flow through small surfaces.  Here are 7 things that you need to know about continuous insulation.

There are several ways to break the bridge across a steel framing member. This can be done by insulated sheathing, designing and installing distance spacers (This will place an air barrier between the framing and the exterior sheathing), adding a reflective surface to the space and this way the air barrier has an increased R-Value and alternate framing members.  In order to ensure the best results, this requires the full involvement of the design team.  Insulation to extreme levels can be achieved with any building, however the return on investment can be reached relatively quickly.
The different types of foam insulation are: expanded polystyrene (EPS), extruded polystyrene (XPS) and polyisocyanurate (Polyiso).   The way EPS is manufactured is by expanding polystyrene beads to fill a form.  Depending on the density of the beads, vapor resistance, thermal resistance and structural strength can be varied.  The way XPS is created is by extruding a mixture called molten polysterene and then using a blowing agent through a die at high temperatures. You can find polyiso anywhere, it is commercially available and it is made up by polyurethane foam modified with polyisocaynurate.  This mix together, will increase the fire resistance while maintaining R-values and strength.

If you want to add space, consider a thermal block on the framing member before installing panels. This will allow the wall to retain its full rating and prevent the short cut caused by fasteners.  
The varieties in facings come with different advantages. One example is the foil facing which helps reduce heat conductivity. Another example is kraft paper facing which is commonly used for batt insulation and works well for increasing the permeability rating on vapor infiltration.  Facing is so important and it does more than just moisture control and heat conductivity.  In sports-type buildings, often constructed using metal building systems, a fiberglass and polyester blend facing will prevent the insulation from being punctured by sharp and blunt objects.  Foil facing has become the most popular in continuous insulation and us generally used as a radiant barrier, in cool roof applications. To read more advantages and tips about continuous insulation, click here.

 

1 comment:

  1. Thank you for this great information about continuous insulation! I have been wanting to get the insulation redone on my home, but I would really like to be sure that it is done well. As far as I have seen, I think that it would be great to get continuous insulation put in. I will have to look into the different types of foam that you have listed, but I think that for right now, I am off to a great start! http://brandxmetals.com/products/diamond-furr/3-inch-c-i-system/diamond-furr-3-ci-sys-os-corner-detail

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