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What is XPS Foam?

XPS foam, also known as Extruded Polystyrene, has an innate combination of properties that make it one of the most efficient insulating materials available. The closed-cell structure, responsible for the foam’s excellent moisture resistance, also contributes to its high compressive strength and superior thermal performance.

Boardstock Insulation Applications

Roofs – new or retrofit

High R-value, high compressive strength, light weight and moisture resistance make

XPS foam a cost-efficient, effective choice for commercial roofing insulation –

whether new or retrofit—sometimes referred to as "reroofing". The weather

resistance properties allow XPS to be installed under the membrane (the conventional system) or over the membrane (the PMR system) to protect it from damage and weather.


Used with either wood or metal stud framing, XPS foam insulation provides a

highly moisture resistant thermal break envelope outside the studs to sheath

and insulate all framing. XPS offers significant insulating performance while

also reducing air infiltration. New or retrofit siding, brick and stucco finishes

can then be applied.

Applied to masonry or concrete interior walls, XPS insulation can be used with

furring systems or other attachment methods to provide energy efficiency.

Placed within the cavity, XPS insulation retards heat transmission and

reduces the passage of water vapor. XPS will not settle.

Used in a “hard coat” cementitious, mechanically attached exterior insulation

system, XPS can substantially reduce thermal bridging. The system provides

a sturdy, thermally-efficient and attractive exterior.


The long term R-value, high compressive strength, exceptional moisture

resistance and excellent resistance to chemicals typically found in soil

make XPS ideal for use as foundation insulation.

Other XPS applications include:

Exterior Insulation Finish Systems (EIFS)

Insulating Concrete Form Systems (ICFs)

Structural Insulated Panels (SIPs)

Earth shelters

Swimming pools

Recreational vehicles

Agricultural buildings

Low temperature spaces

Ice rinks

Precast concrete systems

Plaza decks

Highway insulation

Airport runway insulation


Fanfold Sheet Products

Air infiltration reduction

XPS in fanfold sheet form is used, in part, as an air infiltration barrier. The leakage of air through

all the normal seams and tiny cracks of the exterior walls can account for as much as 30 percent

of the heat loss in a typical home. Wrapping the home with continuous fanfold sheets of XPS

foam can significantly reduce energy loss.

Water vapor permeability control

Fanfold sheets are a barrier to liquid water. However, the product design

(thickness of the sheet; facer characteristics) allows the transfer of water vapor when

critical for the application. This property is known as permeance and is expressed in “perms.”


XPS fanfold sheets offer the opportunity to significantly reduce air infiltration, making them

the preferred choice in manufactured housing, RV and residing applications. Their

compressive strength and rigidity provide a level firm base on which to apply new siding.

Additionally, XPS fanfold sheets offer dependable moisture resistance and good sound

insulation properties.


XPS offers durability, ease of installation and moisture resistance when used as a

protection board over foundation wall waterproofing.

Above photo shows XPS foam dragon prop wall decor machined with a CNC router



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